ESQuery is a library for querying the AST output by Esprima for patterns of syntax using a CSS style selector system. Check out the demo:
The following selectors are supported:
- AST node type:
ForStatement -
wildcard:
* -
attribute existence:
[attr] -
attribute value:
[attr="foo"]or[attr=123] - attribute regex:
[attr=/foo.*/] - attribute conditons:
[attr!="foo"],[attr>2],[attr<3],[attr>=2], or[attr<=3] - nested attribute:
[attr.level2="foo"] - field:
FunctionDeclaration > Identifier.id -
First or last child:
:first-childor:last-child -
nth-child (no ax+b support):
:nth-child(2) -
nth-last-child (no ax+b support):
:nth-last-child(1) -
descendant:
ancestor descendant -
child:
parent > child -
following sibling:
node ~ sibling -
adjacent sibling:
node + adjacent -
negation:
:not(ForStatement) -
matches-any:
:matches([attr] > :first-child, :last-child) -
subject indicator:
!IfStatement > [name="foo"] - class of AST node:
:statement,:expression,:declaration,:function, or:pattern
