Magic String

This is a port of Rich Haris’ magic-string module, written for the Deno/Browser environment.

Differences from the original

This repo was written in Typescript instead of Javascript. Because of this, I removed some explicit type validation in the original code; the user is responsible to use the API in conformance with the Typescript typings.
Deprecated APIs (insertLeft, insertRight, locate, and locateOrigin) were not ported.
In keeping with Deno style, the entry point is mod.ts instead of index.ts.

Usage

MagicString

import MagicString from 'https://deno.land/x/magic_string/mod.ts';
const s = new MagicString( 'problems = 99' );

s.overwrite( 0, 8, 'answer' );
s.toString(); // 'answer = 99'

s.overwrite( 11, 13, '42' ); // character indices always refer to the original string
s.toString(); // 'answer = 42'

s.prepend( 'const ' ).append( ';' ); // most methods are chainable

console.log('=== FILE: converted.js');
console.log(s.toString());
// 'const answer = 42;'

const map = s.generateMap({
  source: 'source.js',
  file: 'converted.js.map',
  includeContent: true
}); // generates a v3 sourcemap
console.log('\n=== FILE: converted.js.map');
console.log(map.toString());

Bundle

import MagicString, { Bundle } from 'https://deno.land/x/magic_string/mod.ts';

const bundle = new Bundle();

bundle.addSource({
  filename: 'foo.js',
  content: new MagicString( 'var answer = 42;' )
});

bundle.addSource({
  filename: 'bar.js',
  content: new MagicString( 'console.log( answer )' )
});

// Advanced: a source can include an `indentExclusionRanges` property
// alongside `filename` and `content`. This will be passed to `s.indent()`

bundle.indent() // optionally, pass an indent string, otherwise it will be guessed
  .prepend( '(function () {\n' )
  .append( '\n}());' );

console.log('=== FILE: bundled.js');
console.log(bundle.toString());
// (function () {
//   var answer = 42;
//   console.log( answer );
// }());

const map = bundle.generateMap({
  file: 'bundle.js',
  includeContent: true,
  hires: true
});
console.log('\n=== FILE: bundled.js.map');
console.log(map.toString());