Astring

A tiny and fast ESTree formatted AST to JavaScript code generator.

Key features:

• Supports ECMAScript versions 5 and 6.
• Considerably faster than Escodegen and Esotope.
• No dependencies and small footprint (11 KB minified, 3 KB gziped).
• Output code is readable and executable.
• Reduced formatting options.

Installation

If you haven't already, install the Node Package Manager.

Checkout this repository, then run from withing the repository:

npm install

Alternatively, install it with the Node Package Manager:

npm install astring

Usage

The path to the module file is dist/astring.min.js and works both in a browser or Node environment. When run in a browser, it creates a global variable astring.

The astring module consists of a function that takes two arguments node and options. It returns a string representing the rendered code of the provided AST node. The options are:

• indent: string to use for indentation (defaults to \t)
• lineEnd: string to use for line endings (defaults to \n)
• startingIndentLevel: indent level to start from (defaults to 0)

Example

This example uses Acorn, a blazingly fast JavaScript parser and AST producer. It is the perfect companion of Astring.

// Import modules
acorn = require( 'acorn' )
astring = require( 'astring' )

// Example code
code = "let answer = 4 + 7 * 5 + 3;"

// Parse it into an AST
node = acorn.parse( code, { ecmaVersion: 6 } )

// Set formatting options
options = {
    indent: '   ',
    lineEnd: '\n'
}

// Format it
result = astring( node, options )

// Check it
if ( code === result )
    console.log( 'It works !' )
else
    console.log( 'Something went wrong…' )

Caveats

Testing is not done yet (undergoing).