Shift Query

Shift-query is a library for querying a Shift AST for patterns of syntax using a CSS style selector system.

This is a fork and update of esquery to be used with the Shift suite of parsers and tools. No significant functionality has been changed.

Demo

Check out the demo here

Install

$ npm install shift-query

Usage

const query = require('shift-query');
const { parseScript } = require('shift-parser');

const ast = parseScript(`
function add(a, b) { return a + b };
function noop() { };

const sum = add(1,2);
`);

const binding = query(ast, '[name="sum"]');
console.log(binding);
/*
[ BindingIdentifier { type: 'BindingIdentifier', name: 'sum' } ]
*/

const functionsWithParams = query(ast, '[params.items.length>0]');
console.log(functionsWithParams);

/*
[ FunctionDeclaration {
  type: 'FunctionDeclaration',
  isAsync: false,
  isGenerator: false,
  name: BindingIdentifier { type: 'BindingIdentifier', name: 'add' },
  params: FormalParameters { type: 'FormalParameters', items: [Array], rest: null },
  body: FunctionBody { type: 'FunctionBody', directives: [], statements: [Array] } } ]
*/

The following selectors are supported:

• AST node type: FunctionDeclaration
• 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 > IdentifierExpression.name
• First or last child: :first-child or :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(ExpressionStatement)
• matches-any: :matches([attr] > :first-child, :last-child)
• subject indicator: !IfStatement > [name="foo"]
• class of AST node: :statement, :expression, :declaration, :function, or :target