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Esprima (esprima.org, BSD license) is a high performance,
standard-compliant ECMAScript
parser written in ECMAScript (also popularly known as
JavaScript).
Esprima is created and maintained by Ariya Hidayat,
with the help of many contributors.


Features


Full support for ECMAScript 2017 (ECMA-262 8th Edition)
Sensible syntax tree format as standardized by ESTree project

Experimental support for JSX, a syntax extension for React

Optional tracking of syntax node location (index-based and line-column)

Heavily tested (~1500 unit tests with full code coverage)


API

Esprima can be used to perform lexical analysis (tokenization) or syntactic analysis (parsing) of a JavaScript program.

A simple example on Node.js REPL:

> var esprima = require('esprima');
> var program = 'const answer = 42';

> esprima.tokenize(program);
[ { type: 'Keyword', value: 'const' },
  { type: 'Identifier', value: 'answer' },
  { type: 'Punctuator', value: '=' },
  { type: 'Numeric', value: '42' } ]

> esprima.parseScript(program);
{ type: 'Program',
  body:
   [ { type: 'VariableDeclaration',
       declarations: [Object],
       kind: 'const' } ],
  sourceType: 'script' }


For more information, please read the complete documentation.