visitors.js 8.46 KB
"use strict";

exports.__esModule = true;

var _typeof2 = require("babel-runtime/helpers/typeof");

var _typeof3 = _interopRequireDefault(_typeof2);

var _keys = require("babel-runtime/core-js/object/keys");

var _keys2 = _interopRequireDefault(_keys);

var _getIterator2 = require("babel-runtime/core-js/get-iterator");

var _getIterator3 = _interopRequireDefault(_getIterator2);

exports.explode = explode;
exports.verify = verify;
exports.merge = merge;

var _virtualTypes = require("./path/lib/virtual-types");

var virtualTypes = _interopRequireWildcard(_virtualTypes);

var _babelMessages = require("babel-messages");

var messages = _interopRequireWildcard(_babelMessages);

var _babelTypes = require("babel-types");

var t = _interopRequireWildcard(_babelTypes);

var _clone = require("lodash/clone");

var _clone2 = _interopRequireDefault(_clone);

function _interopRequireWildcard(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = {}; if (obj != null) { for (var key in obj) { if (Object.prototype.hasOwnProperty.call(obj, key)) newObj[key] = obj[key]; } } newObj.default = obj; return newObj; } }

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

function explode(visitor) {
  if (visitor._exploded) return visitor;
  visitor._exploded = true;

  for (var nodeType in visitor) {
    if (shouldIgnoreKey(nodeType)) continue;

    var parts = nodeType.split("|");
    if (parts.length === 1) continue;

    var fns = visitor[nodeType];
    delete visitor[nodeType];

    for (var _iterator = parts, _isArray = Array.isArray(_iterator), _i = 0, _iterator = _isArray ? _iterator : (0, _getIterator3.default)(_iterator);;) {
      var _ref;

      if (_isArray) {
        if (_i >= _iterator.length) break;
        _ref = _iterator[_i++];
      } else {
        _i = _iterator.next();
        if (_i.done) break;
        _ref = _i.value;
      }

      var part = _ref;

      visitor[part] = fns;
    }
  }

  verify(visitor);

  delete visitor.__esModule;

  ensureEntranceObjects(visitor);

  ensureCallbackArrays(visitor);

  for (var _iterator2 = (0, _keys2.default)(visitor), _isArray2 = Array.isArray(_iterator2), _i2 = 0, _iterator2 = _isArray2 ? _iterator2 : (0, _getIterator3.default)(_iterator2);;) {
    var _ref2;

    if (_isArray2) {
      if (_i2 >= _iterator2.length) break;
      _ref2 = _iterator2[_i2++];
    } else {
      _i2 = _iterator2.next();
      if (_i2.done) break;
      _ref2 = _i2.value;
    }

    var _nodeType3 = _ref2;

    if (shouldIgnoreKey(_nodeType3)) continue;

    var wrapper = virtualTypes[_nodeType3];
    if (!wrapper) continue;

    var _fns2 = visitor[_nodeType3];
    for (var type in _fns2) {
      _fns2[type] = wrapCheck(wrapper, _fns2[type]);
    }

    delete visitor[_nodeType3];

    if (wrapper.types) {
      for (var _iterator4 = wrapper.types, _isArray4 = Array.isArray(_iterator4), _i4 = 0, _iterator4 = _isArray4 ? _iterator4 : (0, _getIterator3.default)(_iterator4);;) {
        var _ref4;

        if (_isArray4) {
          if (_i4 >= _iterator4.length) break;
          _ref4 = _iterator4[_i4++];
        } else {
          _i4 = _iterator4.next();
          if (_i4.done) break;
          _ref4 = _i4.value;
        }

        var _type = _ref4;

        if (visitor[_type]) {
          mergePair(visitor[_type], _fns2);
        } else {
          visitor[_type] = _fns2;
        }
      }
    } else {
      mergePair(visitor, _fns2);
    }
  }

  for (var _nodeType in visitor) {
    if (shouldIgnoreKey(_nodeType)) continue;

    var _fns = visitor[_nodeType];

    var aliases = t.FLIPPED_ALIAS_KEYS[_nodeType];

    var deprecratedKey = t.DEPRECATED_KEYS[_nodeType];
    if (deprecratedKey) {
      console.trace("Visitor defined for " + _nodeType + " but it has been renamed to " + deprecratedKey);
      aliases = [deprecratedKey];
    }

    if (!aliases) continue;

    delete visitor[_nodeType];

    for (var _iterator3 = aliases, _isArray3 = Array.isArray(_iterator3), _i3 = 0, _iterator3 = _isArray3 ? _iterator3 : (0, _getIterator3.default)(_iterator3);;) {
      var _ref3;

      if (_isArray3) {
        if (_i3 >= _iterator3.length) break;
        _ref3 = _iterator3[_i3++];
      } else {
        _i3 = _iterator3.next();
        if (_i3.done) break;
        _ref3 = _i3.value;
      }

      var alias = _ref3;

      var existing = visitor[alias];
      if (existing) {
        mergePair(existing, _fns);
      } else {
        visitor[alias] = (0, _clone2.default)(_fns);
      }
    }
  }

  for (var _nodeType2 in visitor) {
    if (shouldIgnoreKey(_nodeType2)) continue;

    ensureCallbackArrays(visitor[_nodeType2]);
  }

  return visitor;
}

function verify(visitor) {
  if (visitor._verified) return;

  if (typeof visitor === "function") {
    throw new Error(messages.get("traverseVerifyRootFunction"));
  }

  for (var nodeType in visitor) {
    if (nodeType === "enter" || nodeType === "exit") {
      validateVisitorMethods(nodeType, visitor[nodeType]);
    }

    if (shouldIgnoreKey(nodeType)) continue;

    if (t.TYPES.indexOf(nodeType) < 0) {
      throw new Error(messages.get("traverseVerifyNodeType", nodeType));
    }

    var visitors = visitor[nodeType];
    if ((typeof visitors === "undefined" ? "undefined" : (0, _typeof3.default)(visitors)) === "object") {
      for (var visitorKey in visitors) {
        if (visitorKey === "enter" || visitorKey === "exit") {
          validateVisitorMethods(nodeType + "." + visitorKey, visitors[visitorKey]);
        } else {
          throw new Error(messages.get("traverseVerifyVisitorProperty", nodeType, visitorKey));
        }
      }
    }
  }

  visitor._verified = true;
}

function validateVisitorMethods(path, val) {
  var fns = [].concat(val);
  for (var _iterator5 = fns, _isArray5 = Array.isArray(_iterator5), _i5 = 0, _iterator5 = _isArray5 ? _iterator5 : (0, _getIterator3.default)(_iterator5);;) {
    var _ref5;

    if (_isArray5) {
      if (_i5 >= _iterator5.length) break;
      _ref5 = _iterator5[_i5++];
    } else {
      _i5 = _iterator5.next();
      if (_i5.done) break;
      _ref5 = _i5.value;
    }

    var fn = _ref5;

    if (typeof fn !== "function") {
      throw new TypeError("Non-function found defined in " + path + " with type " + (typeof fn === "undefined" ? "undefined" : (0, _typeof3.default)(fn)));
    }
  }
}

function merge(visitors) {
  var states = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : [];
  var wrapper = arguments[2];

  var rootVisitor = {};

  for (var i = 0; i < visitors.length; i++) {
    var visitor = visitors[i];
    var state = states[i];

    explode(visitor);

    for (var type in visitor) {
      var visitorType = visitor[type];

      if (state || wrapper) {
        visitorType = wrapWithStateOrWrapper(visitorType, state, wrapper);
      }

      var nodeVisitor = rootVisitor[type] = rootVisitor[type] || {};
      mergePair(nodeVisitor, visitorType);
    }
  }

  return rootVisitor;
}

function wrapWithStateOrWrapper(oldVisitor, state, wrapper) {
  var newVisitor = {};

  var _loop = function _loop(key) {
    var fns = oldVisitor[key];

    if (!Array.isArray(fns)) return "continue";

    fns = fns.map(function (fn) {
      var newFn = fn;

      if (state) {
        newFn = function newFn(path) {
          return fn.call(state, path, state);
        };
      }

      if (wrapper) {
        newFn = wrapper(state.key, key, newFn);
      }

      return newFn;
    });

    newVisitor[key] = fns;
  };

  for (var key in oldVisitor) {
    var _ret = _loop(key);

    if (_ret === "continue") continue;
  }

  return newVisitor;
}

function ensureEntranceObjects(obj) {
  for (var key in obj) {
    if (shouldIgnoreKey(key)) continue;

    var fns = obj[key];
    if (typeof fns === "function") {
      obj[key] = { enter: fns };
    }
  }
}

function ensureCallbackArrays(obj) {
  if (obj.enter && !Array.isArray(obj.enter)) obj.enter = [obj.enter];
  if (obj.exit && !Array.isArray(obj.exit)) obj.exit = [obj.exit];
}

function wrapCheck(wrapper, fn) {
  var newFn = function newFn(path) {
    if (wrapper.checkPath(path)) {
      return fn.apply(this, arguments);
    }
  };
  newFn.toString = function () {
    return fn.toString();
  };
  return newFn;
}

function shouldIgnoreKey(key) {
  if (key[0] === "_") return true;

  if (key === "enter" || key === "exit" || key === "shouldSkip") return true;

  if (key === "blacklist" || key === "noScope" || key === "skipKeys") return true;

  return false;
}

function mergePair(dest, src) {
  for (var key in src) {
    dest[key] = [].concat(dest[key] || [], src[key]);
  }
}