[ONOS-3892,3895,3882,3883,3896]Unit test of yang container, list, leaf, leaf-list parser

Change-Id: Iae040d9d354e012584db8adc0aa7ff1ea4c099a0

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for config listener.
+ */
+public class ConfigListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid config statement.
+     */
+    @Test
+    public void processConfigTrue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ConfigTrue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the Config value is set correctly.
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.isConfig(), is(true));
+    }
+
+    /**
+     * Checks valid config statement.
+     */
+    @Test
+    public void processConfigFalse() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ConfigFalse.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the Config value is set correctly.
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.isConfig(), is(false));
+    }
+
+    /**
+     * Checks invalid config statement and expects parser exception.
+     */
+    @Test
+    public void processConfigWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing ';' at '}'");
+        YangNode node = manager.getDataModel("src/test/resources/ConfigWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks invalid config statement and expects parser exception.
+     */
+    @Test
+    public void processConfigInvalidValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'invalid' expecting {'false', 'true'}");
+        YangNode node = manager.getDataModel("src/test/resources/ConfigInvalidValue.yang");
+    }
+
+    /**
+     * Checks invalid config statement and expects parser exception.
+     */
+    @Test
+    public void processConfigEmptyValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing {'false', 'true'} at ';'");
+        YangNode node = manager.getDataModel("src/test/resources/ConfigEmptyValue.yang");
+    }
+
+    /**
+     * Checks config statement as sub-statement of module.
+     */
+    @Test
+    public void processModuleSubStatementConfig() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'config' expecting {'augment', 'choice', 'contact', 'container'," +
+                " 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import', 'include', " +
+                "'leaf', 'leaf-list', 'list', 'namespace', 'notification', 'organization', 'prefix', 'reference'," +
+                " 'revision', 'rpc', 'typedef', 'uses', 'yang-version', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementConfig.yang");
+    }
+
+    /**
+     * Checks config statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementConfig() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementConfig.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the config value is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+        assertThat(container.isConfig(), is(true));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = container.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks config statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementConfig() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementConfig.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module and config value is set.
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.isConfig(), is(true));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks valid config statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementConfig() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementConfig.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether config value is set correctly.
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.isConfig(), is(true));
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing container listener.
+ */
+public class ContainerListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks container statement as sub-statement of module.
+     */
+    @Test
+    public void processModuleSubStatementContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementContainer.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the container is child of module
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("valid"));
+    }
+
+    /**
+     * Checks container statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementContainer.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the container is child of module
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("ospf"));
+
+        // Check whether the container is child of container
+        YangContainer yangContainer1 = (YangContainer) yangContainer.getChild();
+        assertThat(yangContainer1.getName(), is("valid"));
+    }
+
+    /**
+     * Checks container statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementContainer() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementContainer.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList1 = (YangList) yangNode.getChild();
+        assertThat(yangList1.getName(), is("ospf"));
+
+        ListIterator<String> keyList = yangList1.getKeyList().listIterator();
+        assertThat(keyList.next(), is("process-id"));
+
+        // Check whether the list is child of list
+        YangContainer yangContainer = (YangContainer) yangList1.getChild();
+        assertThat(yangContainer.getName(), is("interface"));
+    }
+
+    /**
+     * Checks container with all its sub-statements.
+     */
+    @Test
+    public void processContainerSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the container is child of module
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+
+        // Check whether container properties as set correctly.
+        assertThat(yangContainer.getName(), is("ospf"));
+
+        assertThat(yangContainer.isConfig(), is(true));
+        assertThat(yangContainer.getPresence(), is("\"ospf logs\""));
+        assertThat(yangContainer.getDescription(), is("\"container description\""));
+        assertThat(yangContainer.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(yangContainer.getReference(), is("\"container reference\""));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangContainer.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks cardinality of sub-statements of container.
+     */
+    @Test
+    public void processContainerSubStatementCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Invalid cardinality in reference before processing.");
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementCardinality.yang");
+    }
+
+    /**
+     * Checks container as root node.
+     */
+    @Test
+    public void processContainerRootNode() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("no viable alternative at input 'container'");
+        YangNode node = manager.getDataModel("src/test/resources/ContainerRootNode.yang");
+    }
+
+    /**
+     * Checks invalid identifier for container statement.
+     */
+    @Test
+    public void processContainerInvalidIdentifier() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input '1valid' expecting IDENTIFIER");
+        YangNode node = manager.getDataModel("src/test/resources/ContainerInvalidIdentifier.yang");
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for description listener.
+ */
+public class DescriptionListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid description statement.
+     */
+    @Test
+    public void processDescriptionValidStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DescriptionValidStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the description is set correctly.
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+    }
+
+    /**
+     * Checks whether exception is thrown for invalid description statement.
+     */
+    @Test
+    public void processDescriptionWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("extraneous input '}' expecting {';', '+'}");
+        YangNode node = manager.getDataModel("src/test/resources/DescriptionWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks valid description statement as sub-statement of module.
+     */
+    @Test
+    public void processModuleSubStatementDescription() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementDescription.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the description is set correctly.
+        assertThat(yangNode.getDescription(), is("\"Interval before a route is declared invalid\""));
+    }
+
+    /**
+     * Checks valid description statement as sub-statement of module.
+     */
+    @Test
+    public void processDescriptionEmptyStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DescriptionEmptyStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the description is set correctly.
+        assertThat(yangNode.getDescription(), is("\"\""));
+    }
+
+    /**
+     * Checks valid description statement as sub-statement of revision.
+     */
+    @Test
+    public void processRevisionSubStatementRevision() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionSubStatementRevision.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the description is set correctly.
+        assertThat(yangNode.getDescription(), is("\"module description\""));
+        assertThat(yangNode.getRevision().getDescription(), is("\"revision description\""));
+    }
+
+    /**
+     * Checks description statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementDescription() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementDescription.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the description value is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+        assertThat(container.getDescription(), is("\"container description\""));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = container.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks description statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementDescription() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementDescription.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module and description value is set correctly.
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.isConfig(), is(true));
+        assertThat(yangList.getDescription(), is("\"list description\""));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks valid description statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementDescription() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementDescription.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether description value is set correctly.
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for key listener.
+ */
+public class KeyListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks key statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementKey() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementKey.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        ListIterator<String> keyList = yangList.getKeyList().listIterator();
+        assertThat(keyList.next(), is("invalid-interval"));
+    }
+
+    /**
+     * Check multiple key values.
+     */
+    @Test
+    public void processMultipleKeyValues() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MultipleKeyValues.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        List<String> keyList = yangList.getKeyList();
+        assertThat(keyList.contains("ospf"), is(true));
+        assertThat(keyList.contains("isis"), is(true));
+    }
+
+    /**
+     * Checks key statement without statement end.
+     */
+    @Test
+    public void processKeyWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'leaf' expecting {';', '+'}");
+        YangNode node = manager.getDataModel("src/test/resources/KeyWithoutStatementEnd.yang");
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing leaf-list listener.
+ */
+public class LeafListListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks all the values of leaf-list sub-statements are set
+     * correctly.
+     */
+    @Test
+    public void processLeafListSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatements.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafListInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafListInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafListInfo.isConfig(), is(true));
+        assertThat(leafListInfo.getMaxElelements(), is(3));
+        assertThat(leafListInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafListInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf-list identifier
+     * starts with digit.
+     */
+    @Test
+    public void processLeafListInvalidIdentifier() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input '1invalid-interval' expecting IDENTIFIER");
+        YangNode node = manager.getDataModel("src/test/resources/LeafListInvalidIdentifier.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf-list keyword
+     * is incorrect.
+     */
+    @Test
+    public void processLeafListInvalidStatement() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'leaflist' expecting {'augment', 'choice', 'contact', 'container'," +
+                " 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import', 'include'," +
+                " 'leaf', 'leaf-list', 'list', 'namespace', 'notification', 'organization', 'prefix', 'reference'," +
+                " 'revision', 'rpc', 'typedef', 'uses', 'yang-version', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/LeafListInvalidStatement.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf-list keyword
+     * without Left brace as per grammar.
+     */
+    @Test
+    public void processLeafListWithoutLeftBrace() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing '{' at 'type'");
+        YangNode node = manager.getDataModel("src/test/resources/LeafListWithoutLeftBrace.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when config statement
+     * cardinality is not as per grammar.
+     */
+    @Test
+    public void processLeafListConfigInvalidCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Invalid cardinality in config before processing.");
+        YangNode node = manager.getDataModel("src/test/resources/LeafListConfigInvalidCardinality.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when units statement
+     * cardinality is not as per grammar.
+     */
+    @Test
+    public void processLeafListUnitsInvalidCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Invalid cardinality in units before processing.");
+        YangNode node = manager.getDataModel("src/test/resources/LeafListUnitsInvalidCardinality.yang");
+    }
+
+    /**
+     * Checks leaf-list statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementLeafList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementLeafList.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        //Check whether the container is child of module.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+
+        // Check whether leaf-list properties as set correctly.
+        ListIterator<YangLeafList> leafListIterator = container.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafListInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafListInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafListInfo.isConfig(), is(true));
+        assertThat(leafListInfo.getMinElements(), is(1));
+        assertThat(leafListInfo.getMaxElelements(), is(2147483647));
+        assertThat(leafListInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafListInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks leaf-list statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementLeafList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementLeafList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        // Check whether leaf-list properties as set correctly.
+        ListIterator<YangLeafList> leafListIterator = yangList.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafListInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafListInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafListInfo.isConfig(), is(true));
+
+        assertThat(leafListInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafListInfo.getReference(), is("\"RFC 6020\""));
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing leaf listener.
+ */
+public class LeafListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks all the values of leaf sub-statements are set
+     * correctly.
+     */
+    @Test
+    public void processLeafSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafSubStatements.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isConfig(), is(true));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf identifier
+     * starts with digit.
+     */
+    @Test
+    public void processLeafInvalidIdentifier() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input '1invalid-interval' expecting IDENTIFIER");
+        YangNode node = manager.getDataModel("src/test/resources/LeafInvalidIdentifier.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf keyword
+     * is incorrect.
+     */
+    @Test
+    public void processLeafInvalidStatement() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'leafs' expecting {'augment', 'choice', 'contact', 'container'," +
+                " 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import', 'include'," +
+                " 'leaf', 'leaf-list', 'list', 'namespace', 'notification', 'organization', 'prefix', 'reference'," +
+                " 'revision', 'rpc', 'typedef', 'uses', 'yang-version', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/LeafInvalidStatement.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when leaf keyword
+     * without Left brace as per grammar.
+     */
+    @Test
+    public void processLeafWithoutLeftBrace() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing '{' at 'type'");
+        YangNode node = manager.getDataModel("src/test/resources/LeafWithoutLeftBrace.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when config statement
+     * cardinality is not as per grammar.
+     */
+    @Test
+    public void processLeafConfigInvalidCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Invalid cardinality in config before processing.");
+        YangNode node = manager.getDataModel("src/test/resources/LeafConfigInvalidCardinality.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when mandatory statement
+     * cardinality is not as per grammar.
+     */
+    @Test
+    public void processLeafMandatoryInvalidCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Invalid cardinality in mandatory before processing.");
+        YangNode node = manager.getDataModel("src/test/resources/LeafMandatoryInvalidCardinality.yang");
+    }
+
+    /**
+     * Checks leaf statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementLeaf() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementLeaf.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        //Check whether the container is child of module.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = container.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isConfig(), is(true));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks leaf statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementLeaf() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementLeaf.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isConfig(), is(true));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing list listener.
+ */
+public class ListListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks list statement as sub-statement of module.
+     */
+    @Test
+    public void processModuleSubStatementList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+
+        ListIterator<String> keyList = yangList.getKeyList().listIterator();
+        assertThat(keyList.next(), is("invalid"));
+    }
+
+    /**
+     * Checks list statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the container is child of module
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("ospf"));
+
+        // Check whether the list is child of container
+        YangList yangList = (YangList) yangContainer.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.getKeyList().contains("invalid"), is(true));
+    }
+
+    /**
+     * Checks list statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementList() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementList.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList1 = (YangList) yangNode.getChild();
+        assertThat(yangList1.getName(), is("ospf"));
+        assertThat(yangList1.getKeyList().contains("process-id"), is(true));
+
+        // Check whether the list is child of list
+        YangList yangList = (YangList) yangList1.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.getKeyList().contains("invalid"), is(true));
+    }
+
+    /**
+     * Checks list with all its sub-statements.
+     */
+    @Test
+    public void processListSubStatements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+
+        // Check whether list properties as set correctly.
+        assertThat(yangList.getName(), is("ospf"));
+        assertThat(yangList.getKeyList().contains("process-id"), is(true));
+
+        assertThat(yangList.isConfig(), is(true));
+        assertThat(yangList.getMaxElelements(), is(10));
+        assertThat(yangList.getMinElements(), is(3));
+        assertThat(yangList.getDescription(), is("\"list description\""));
+        assertThat(yangList.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(yangList.getReference(), is("\"list reference\""));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks cardinality of sub-statements of list.
+     */
+    @Test
+    public void processListSubStatementsCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Invalid cardinality in reference before processing.");
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementsCardinality.yang");
+    }
+
+    /**
+     * Checks list statement without child.
+     */
+    @Test
+    public void processListStatementWithoutChild() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Invalid cardinality in list before processing.");
+        YangNode node = manager.getDataModel("src/test/resources/ListStatementWithoutChild.yang");
+    }
+
+    /**
+     * Checks list as root node.
+     */
+    @Test
+    public void processListAsRootNode() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("no viable alternative at input 'list'");
+        YangNode node = manager.getDataModel("src/test/resources/ListAsRootNode.yang");
+    }
+
+    /**
+     * Checks invalid identifier for list statement.
+     */
+    @Test
+    public void processListInvalidIdentifier() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input '1valid' expecting IDENTIFIER");
+        YangNode node = manager.getDataModel("src/test/resources/ListInvalidIdentifier.yang");
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test case for mandatory listener.
+ */
+public class MandatoryListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid mandatory with value true statement.
+     */
+    @Test
+    public void processMandatoryTrue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MandatoryTrue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the mandatory value is set correctly.
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.isMandatory(), is(true));
+    }
+
+    /**
+     * Checks valid mandatory with value false statement.
+     */
+    @Test
+    public void processMandatoryFalse() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MandatoryFalse.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the mandatory value is set correctly.
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.isMandatory(), is(false));
+    }
+
+    /**
+     * Checks default value of mandatory statement.
+     */
+    @Test
+    public void processMandatoryDefaultValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MandatoryDefaultValue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the mandatory value is set correctly.
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.isMandatory(), is(false));
+    }
+
+    /**
+     * Checks invalid of mandatory statement and expects exception.
+     */
+    @Test
+    public void processMandatoryEmptyStatement() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing {'false', 'true'} at ';'");
+        YangNode node = manager.getDataModel("src/test/resources/MandatoryEmptyStatement.yang");
+    }
+
+    /**
+     * Checks invalid mandatory statement(without statement end) and expects exception.
+     */
+    @Test
+    public void processMandatoryWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing ';' at '}'");
+        YangNode node = manager.getDataModel("src/test/resources/MandatoryWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks mandatory statement as sub-statement of module and expects exception.
+     */
+    @Test
+    public void processModuleSubStatementMandatory() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'mandatory' expecting {'augment', 'choice', 'contact', 'container'," +
+                " 'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import', 'include'," +
+                " 'leaf', 'leaf-list', 'list', 'namespace', 'notification', 'organization', 'prefix', 'reference'," +
+                " 'revision', 'rpc', 'typedef', 'uses', 'yang-version', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementMandatory.yang");
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing max-elements listener.
+ */
+public class MaxElementsListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks max-elements as sub-statements of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementMaxElements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementMaxElements.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getMaxElelements(), is(3));
+    }
+
+    /**
+     * Checks max-elements as sub-statements of list.
+     */
+    @Test
+    public void processListSubStatementMaxElements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementMaxElements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.getMaxElelements(), is(3));
+    }
+
+    /**
+     * Checks whether exception is thrown when invalid max-elements keyword
+     * is given as input.
+     */
+    @Test
+    public void processMaxElementsInvalidStatement() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("extraneous input 'max-element' expecting {'config', 'description', 'if-feature'," +
+                " 'max-elements', 'min-elements', 'must', 'ordered-by', 'reference', 'status', 'type', 'units', " +
+                "'when', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/MaxElementsInvalidStatement.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when max-elements statement without statement
+     * end is given as input.
+     */
+    @Test
+    public void processMaxElementsWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing ';' at 'description'");
+        YangNode node = manager.getDataModel("src/test/resources/MaxElementsWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when max-elements cardinality is not
+     * as per the grammar.
+     */
+    @Test
+    public void processMaxElementsCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Invalid cardinality in max-elements before processing.");
+        YangNode node = manager.getDataModel("src/test/resources/MaxElementsCardinality.yang");
+    }
+
+    /**
+     * Checks unbounded value of max-elements statement.
+     */
+    @Test
+    public void processMaxElementsUnbounded() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/MaxElementsUnbounded.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getMaxElelements(), is(2147483647));
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for testing min-elements listener.
+ */
+public class MinElementsListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks min-elements as sub-statements of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementMinElements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementMinElements.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getMinElements(), is(3));
+    }
+
+    /**
+     * Checks min-elements as sub-statements of list.
+     */
+    @Test
+    public void processListSubStatementMinElements() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementMinElements.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.getMinElements(), is(3));
+    }
+
+    /**
+     * Checks whether exception is thrown when invalid min-elements keyword
+     * is given as input.
+     */
+    @Test
+    public void processMinElementsInvalidKeyword() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("extraneous input 'min-element' expecting {'config', 'description', 'if-feature'," +
+                " 'max-elements', 'min-elements', 'must', 'ordered-by', 'reference', 'status', 'type', 'units'," +
+                " 'when', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/MinElementsInvalidKeyword.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when invalid min-elements value
+     * is given as input.
+     */
+    @Test
+    public void processMinElementsInvalidValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'asd' expecting INTEGER");
+        YangNode node = manager.getDataModel("src/test/resources/MinElementsInvalidValue.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when min-elements statement without statement
+     * end is given as input.
+     */
+    @Test
+    public void processMinElementsWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing ';' at 'description'");
+        YangNode node = manager.getDataModel("src/test/resources/MinElementsWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown when min-elements cardinality is not
+     * as per the grammar.
+     */
+    @Test
+    public void processMinElementsInvalidCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Invalid cardinality in" +
+                " min-elements before processing.");
+        YangNode node = manager.getDataModel("src/test/resources/MinElementsInvalidCardinality.yang");
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
+
+/**
+ * Test cases for presence listener.
+ */
+public class PresenceListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks presence statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementPresence() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementPresence.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("valid"));
+        assertThat(yangContainer.getPresence(), is("\"invalid\""));
+    }
+
+    /**
+     * checks default value of presence statement.
+     */
+    @Test
+    public void processPresenceDefaultValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/PresenceDefaultValue.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module
+        YangContainer yangContainer = (YangContainer) yangNode.getChild();
+        assertThat(yangContainer.getName(), is("valid"));
+        assertThat(yangContainer.getPresence(), is(nullValue()));
+    }
+
+    /**
+     * Checks presence statement without statement end.
+     */
+    @Test
+    public void processPresenceWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'leaf' expecting {';', '+'}");
+        YangNode node = manager.getDataModel("src/test/resources/PresenceWithoutStatementEnd.yang");
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test case for reference listener.
+ */
+public class ReferenceListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid reference statement.
+     */
+    @Test
+    public void processReferenceStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ReferenceStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the reference is set correctly.
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks whether exception is thrown for invalid reference statement.
+     */
+    @Test
+    public void processReferenceWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input '}' expecting {';', '+'}");
+        YangNode node = manager.getDataModel("src/test/resources/ReferenceWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks valid reference statement under module.
+     */
+    @Test
+    public void processModuleSubStatementReference() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementReference.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the reference is set correctly.
+        assertThat(yangNode.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks valid reference statement under module.
+     */
+    @Test
+    public void processReferenceEmptyStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ReferenceEmptyStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the reference is set correctly.
+        assertThat(yangNode.getReference(), is("\"\""));
+    }
+
+    /**
+     * Checks valid reference statement as sub-statement of revision.
+     */
+    @Test
+    public void processRevisionSubStatementReference() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/RevisionSubStatementReference.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the reference is set correctly.
+        assertThat(yangNode.getRevision().getReference(), is("\"revision reference\""));
+    }
+
+    /**
+     * Checks reference statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementReference() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementReference.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the reference value is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+        assertThat(container.getReference(), is("\"container reference\""));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = container.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks reference statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementReference() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementReference.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module and description value is set correctly.
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.isConfig(), is(true));
+        assertThat(yangList.getReference(), is("\"list reference\""));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks valid reference statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementReference() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementReference.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether description value is set correctly.
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getReference(), is("\"RFC 6020\""));
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangContainer;
+import org.onosproject.yangutils.datamodel.YangList;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test cases for status listener.
+ */
+public class StatusListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid status statement.
+     */
+    @Test
+    public void processStatusStatementCurrent() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/StatusStatementCurrent.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the status is set correctly.
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+    }
+
+    /**
+     * Checks valid status statement.
+     */
+    @Test
+    public void processStatusStatementDeprecated() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/StatusStatementDeprecated.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the status is set correctly.
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.DEPRECATED));
+    }
+
+    /**
+     * Checks valid status statement.
+     */
+    @Test
+    public void processStatusStatementObsolete() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/StatusStatementObsolete.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether the status is set correctly.
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.OBSOLETE));
+    }
+
+    /**
+     * Checks whether exception is thrown for invalid status statement.
+     */
+    @Test
+    public void processStatusWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("missing ';' at '}'");
+        YangNode node = manager.getDataModel("src/test/resources/StatusWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks whether exception is thrown for invalid status statement.
+     */
+    @Test
+    public void processStatusInvalidValue() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'invalid' expecting {'current', 'deprecated', 'obsolete'}");
+        YangNode node = manager.getDataModel("src/test/resources/StatusInvalidValue.yang");
+    }
+
+    /**
+     * Checks status statement as sub-statement of module.
+     */
+    @Test
+    public void processModuleSubStatementStatus() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'status' expecting {'augment', 'choice', 'contact', 'container', " +
+                "'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import', 'include'," +
+                " 'leaf', 'leaf-list', 'list', 'namespace', 'notification', 'organization', 'prefix', 'reference', " +
+                "'revision', 'rpc', 'typedef', 'uses', 'yang-version', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementStatus.yang");
+    }
+
+    /**
+     * Checks status statement as sub-statement of container.
+     */
+    @Test
+    public void processContainerSubStatementStatus() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ContainerSubStatementStatus.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether status is set correctly.
+        YangContainer container = (YangContainer) yangNode.getChild();
+        assertThat(container.getName(), is("valid"));
+        assertThat(container.isConfig(), is(true));
+        assertThat(container.getStatus(), is(YangStatusType.OBSOLETE));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = container.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks status statement as sub-statement of list.
+     */
+    @Test
+    public void processListSubStatementStatus() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/ListSubStatementStatus.yang");
+
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        // Check whether the list is child of module and status is set.
+        YangList yangList = (YangList) yangNode.getChild();
+        assertThat(yangList.getName(), is("valid"));
+        assertThat(yangList.isConfig(), is(true));
+        assertThat(yangList.getStatus(), is(YangStatusType.CURRENT));
+
+        // Check whether leaf properties as set correctly.
+        ListIterator<YangLeaf> leafIterator = yangList.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks valid status statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementStatus() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementStatus.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether status is set correctly.
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.isConfig(), is(true));
+        assertThat(leafListInfo.getStatus(), is(YangStatusType.CURRENT));
+    }
+}
\ No newline at end of file

+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Test;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangDataTypes;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+
+/**
+ * Test case for type listener.
+ */
+public class TypeListenerTest {
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks derived statement without contraints.
+     */
+    @Test
+    public void processDerivedTypeStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/DerivedTypeStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"hello\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.DERIVED));
+    }
+
+    /**
+     * Checks valid yang data type.
+     */
+    @Test
+    public void processIntegerTypeStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/IntegerTypeStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+    }
+
+    /**
+     * Checks type for leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementType() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementType.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafListInfo.getDataType().getDataType(), is(YangDataTypes.UINT16));
+    }
+}
\ No newline at end of file

+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.yangutils.parser.impl.listeners;
+
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.junit.rules.ExpectedException;
+import org.onosproject.yangutils.datamodel.YangLeaf;
+import org.onosproject.yangutils.datamodel.YangModule;
+import org.onosproject.yangutils.datamodel.YangNode;
+import org.onosproject.yangutils.datamodel.YangNodeType;
+import org.onosproject.yangutils.datamodel.YangStatusType;
+import org.onosproject.yangutils.datamodel.YangLeafList;
+import org.onosproject.yangutils.parser.exceptions.ParserException;
+import org.onosproject.yangutils.parser.impl.YangUtilsParserManager;
+
+import java.io.IOException;
+import java.util.ListIterator;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.Matchers.nullValue;
+
+/**
+ * Test cases for units listener.
+ */
+public class UnitsListenerTest {
+
+    @Rule
+    public ExpectedException thrown = ExpectedException.none();
+
+    private final YangUtilsParserManager manager = new YangUtilsParserManager();
+
+    /**
+     * Checks valid units statement.
+     */
+    @Test
+    public void processUnitsStatement() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/UnitsStatement.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether units value is set correctly.
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+    }
+
+    /**
+     * Checks invalid units statement as sub-statement of module.
+     */
+    @Test
+    public void processModuleSubStatementUnits() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input 'type' expecting {'augment', 'choice', 'contact', 'container', " +
+                "'description', 'extension', 'deviation', 'feature', 'grouping', 'identity', 'import', " +
+                "'include', 'leaf', 'leaf-list', 'list', 'namespace', 'notification', 'organization', " +
+                "'prefix', 'reference', 'revision', 'rpc', 'typedef', 'uses', 'yang-version', '}'}");
+        YangNode node = manager.getDataModel("src/test/resources/ModuleSubStatementUnits.yang");
+    }
+
+    /**
+     * Checks invalid units statement(without statement end).
+     */
+    @Test
+    public void processUnitsWithoutStatementEnd() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("mismatched input '}' expecting {';', '+'}");
+        YangNode node = manager.getDataModel("src/test/resources/UnitsWithoutStatementEnd.yang");
+    }
+
+    /**
+     * Checks order of units statement in leaf.
+     */
+    @Test
+    public void processUnitsStatementOrder() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/UnitsStatementOrder.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        // Check whether leaf properties is set correctly.
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getDataType().getDataTypeName(), is("\"uint16\""));
+        assertThat(leafInfo.getUnits(), is("\"seconds\""));
+        assertThat(leafInfo.getDescription(), is("\"Interval before a route is declared invalid\""));
+        assertThat(leafInfo.isConfig(), is(true));
+        assertThat(leafInfo.isMandatory(), is(true));
+        assertThat(leafInfo.getStatus(), is(YangStatusType.CURRENT));
+        assertThat(leafInfo.getReference(), is("\"RFC 6020\""));
+    }
+
+    /**
+     * Checks the default value of unit statement.
+     */
+    @Test
+    public void processUnitsDefaultValue() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/UnitsDefaultValue.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeaf> leafIterator = yangNode.getListOfLeaf().listIterator();
+        YangLeaf leafInfo = leafIterator.next();
+
+        assertThat(leafInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafInfo.getUnits(), is(nullValue()));
+    }
+
+    /**
+     * Checks invalid occurance of units statement as sub-statement of leaf.
+     */
+    @Test
+    public void processUnitsStatementCardinality() throws IOException, ParserException {
+        thrown.expect(ParserException.class);
+        thrown.expectMessage("Internal parser error detected: Invalid cardinality in units before processing.");
+        YangNode node = manager.getDataModel("src/test/resources/UnitsStatementCardinality.yang");
+    }
+
+    /**
+     * Checks valid units statement as sub-statement of leaf-list.
+     */
+    @Test
+    public void processLeafListSubStatementUnits() throws IOException, ParserException {
+
+        YangNode node = manager.getDataModel("src/test/resources/LeafListSubStatementUnits.yang");
+
+        // Check whether the data model tree returned is of type module.
+        assertThat((node instanceof YangModule), is(true));
+
+        // Check whether the node type is set properly to module.
+        assertThat(node.getNodeType(), is(YangNodeType.MODULE_NODE));
+
+        // Check whether the module name is set correctly.
+        YangModule yangNode = (YangModule) node;
+        assertThat(yangNode.getName(), is("Test"));
+
+        ListIterator<YangLeafList> leafListIterator = yangNode.getListOfLeafList().listIterator();
+        YangLeafList leafListInfo = leafListIterator.next();
+
+        // Check whether units value is set correctly.
+        assertThat(leafListInfo.getLeafName(), is("invalid-interval"));
+        assertThat(leafListInfo.getUnits(), is("\"seconds\""));
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        config ;
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config false;
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        config invalid;
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        config false
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container 1valid {
+        reference "RFC 6020";
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+container valid {
+    reference "RFC 6020";
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container valid {
+        reference "RFC 6020";
+        reference "RFC 6020";
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container valid {
+        config true;
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            description "Interval before a route is declared invalid";
+            mandatory true;
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container ospf {
+        container valid {
+            leaf invalid-interval {
+                type "uint16";
+                units "seconds";
+                status current;
+                reference "RFC 6020";
+            }
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container valid {
+        description "container description";
+        config true;
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            description "Interval before a route is declared invalid";
+            mandatory true;
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
+

+
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container valid {
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            description "Interval before a route is declared invalid";
+            config true;
+            mandatory true;
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container valid {
+        leaf-list invalid-interval {
+            type "uint16";
+            units "seconds";
+            description "Interval before a route is declared invalid";
+            config true;
+            min-elements 1;
+            max-elements unbounded;
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container ospf {
+        list valid {
+            key "invalid";
+            leaf invalid-interval {
+                type "uint16";
+                units "seconds";
+                status current;
+                reference "RFC 6020";
+            }
+        }
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container valid {
+        presence "invalid";
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container valid {
+        reference "container reference";
+        config true;
+        leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container valid {
+        config true;
+        status obsolete;
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            description "Interval before a route is declared invalid";
+            mandatory true;
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container ospf {
+        presence "ospf logs";
+        config true;
+        description "container description";
+        status current;
+        reference "container reference";
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "hello";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    description "";
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        description "Interval before a " + "route is declared invalid";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+      type "uint16";
+      description "Interval before a " + "route is declared invalid"
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        key "invalid"
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+       type "uint16";
+       units "seconds";
+       description "Interval before a route is declared invalid";
+       config true;
+       config false;
+       mandatory true;
+       status current;
+       reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf 1invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leafs invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        config false;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list 1invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaflist invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        max-elements 3;
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        min-elements 3;
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        max-elements 3;
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        units "minutes";
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval 
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        mandatory true;
+        mandatory false;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval 
+    type "uint16";
+    units "seconds";
+    description "Interval before a route is declared invalid";
+    config true;
+    mandatory true;
+    status current;
+    reference "RFC 6020";
+    }
+}
\ No newline at end of file

+list valid {
+    reference "RFC 6020";
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list 1valid {
+        key "invalid-interval";
+        reference "RFC 6020";
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        key "invalid-interval";
+        config true;
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            description "Interval before a route is declared invalid";
+            mandatory true;
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list ospf {
+        key "process-id";
+        container interface {
+            leaf invalid-interval {
+                type "uint16";
+                units "seconds";
+                status current;
+                reference "RFC 6020";
+            }
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+    key "invalid-interval";
+    description "list description";
+    config true;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        key "invalid-interval";
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        key "invalid-interval";
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            description "Interval before a route is declared invalid";
+            config true;
+            mandatory true;
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+
+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        key "invalid-interval";
+        leaf-list invalid-interval {
+            type "uint16";
+            units "seconds";
+            description "Interval before a route is declared invalid";
+            config true;
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list ospf {
+        key "process-id";
+        list valid {
+            key "invalid";
+            leaf invalid-interval {
+                type "uint16";
+                units "seconds";
+                status current;
+                reference "RFC 6020";
+            }
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        key "invalid-interval";
+        max-elements 3;
+        leaf-list invalid-interval {
+            type "uint16";
+            units "seconds";
+            description "Interval before a route is declared invalid";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        key "invalid-interval";
+        min-elements 3;
+        leaf-list invalid-interval {
+            type "uint16";
+            units "seconds";
+            description "Interval before a route is declared invalid";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        key "invalid-interval";
+        reference "list reference";
+        config true;
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            description "Interval before a route is declared invalid";
+            mandatory true;
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        key "invalid-interval";
+        status current;
+        config true;
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            description "Interval before a route is declared invalid";
+            mandatory true;
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list ospf {
+        key "process-id";
+        config true;
+        max-elements 10;
+        min-elements 3;
+        description "list description";
+        status current;
+        reference "list reference";
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        key "invalid-interval";
+        reference "RFC 6020";
+        reference "RFC 6020";
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        mandatory ;
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        mandatory false;
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+    type "uint16";
+    mandatory false
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        max-elements 4;
+        max-elements 6;
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        max-element 3;
+        description "Interval before a route is declared invalid;
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+       type "uint16";
+       max-elements unbounded;
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+    type "uint16";
+    units "seconds";
+    max-elements 3
+    description "Interval before a route is declared invalid";
+    config true;
+    status current;
+    reference "RFC 6020";
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        min-elements 4;
+        min-elements 6;
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        min-element 3;
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+        type "uint16";
+        units "seconds";
+        min-elements asd;
+        description "Interval before a route is declared invalid";
+        config true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf-list invalid-interval {
+    type "uint16";
+    units "seconds";
+    min-elements 3
+    description "Interval before a route is declared invalid";
+    config true;
+    status current;
+    reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    config invalid;
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container valid {
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    description "Interval before a route is declared invalid";
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        key "invalid";
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    mandatory false;
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    reference "RFC 6020";
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    status current;
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    type "uint16";
+    units "seconds";
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    list valid {
+        key "ospf isis";
+        leaf ospf {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+        leaf isis {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container valid {
+        leaf ospf {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    container valid {
+        presence "invalid"
+        leaf invalid-interval {
+            type "uint16";
+            units "seconds";
+            status current;
+            reference "RFC 6020";
+        }
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    reference "";
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        reference "RFC 6020"
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    description "module description";
+    revision 2007-06-09 {
+        reference "revision reference";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    description "module description";
+    revision 2007-06-09 {
+        description "revision description";
+    }
+}
+

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+        leaf invalid-interval {
+        type "uint16";
+        status invalid;
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        status deprecated;
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        status obsolete;
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        status current
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        description "Interval before a route is declared invalid";
+        config true;
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+    }
+}
\ No newline at end of file

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds";
+        units "minutes";
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        units "seconds";
+        type "uint16";
+        description "Interval before a route is declared invalid";
+        config true;
+        mandatory true;
+        status current;
+        reference "RFC 6020";
+    }
+}

+module Test {
+    yang-version 1;
+    namespace http://huawei.com;
+    prefix Ant;
+    leaf invalid-interval {
+        type "uint16";
+        units "seconds"
+    }
+}