Bare-module-lexer NPM

bare-module-lexer

Heuristic lexer for detecting imports and exports in JavaScript modules. It trades off correctness for performance, aiming to reliably support the most common import and export patterns with as little overhead as possible.

Usage

const lex = require('bare-module-lexer')

lex(`
  const foo = require('./foo.js')
  exports.bar = 42
`)

// {
//   imports: [
//     { specifier: './foo.js', type: REQUIRE, names: [], position: [ 15, 24, 32 ] }
//   ],
//   exports: [
//     { name: 'bar', position: [ 37, 45, 48 ] }
//   ]
// }

API

`const { imports, exports } = lex(source[, encoding][, options])`

imports is an array of objects with the following shape:

imports = {
  specifier: 'string',
  type: number,
  names: ['string'],
  position: [
    number, // Import start
    number, // Specifier start
    number // Specifier end
  ]
}

exports is an array of objects with the following shape:

exports = {
  name: 'string',
  position: [
    number, // Export start
    number, // Name start
    number // Name end
  ]
}

Options are reserved.

`lex.constants`

Constant	Description
`REQUIRE`	CommonJS `require()`.
`IMPORT`	ES module `import`.
`DYNAMIC`	ES module `import()` if `IMPORT` is set.
`ADDON`	CommonJS `require.addon()` if `REQUIRE` is set, or ES module `import.meta.addon()` if `IMPORT` is set.
`ASSET`	CommonJS `require.asset()` if `REQUIRE` is set, or ES module `import.meta.asset()` if `IMPORT` is set.
`RESOLVE`	CommonJS `require.resolve()` or `require.addon.resolve()` if `REQUIRE` and optionally `ADDON` are set, or ES module `import.meta.resolve()` or `import.meta.addon.resolve()` if `IMPORT` and optionally `ADDON` are set.
`REEXPORT`	Re-export of a CommonJS `require()` if `REQUIRE` is set, or ES module `export from` if `IMPORT` is set.