743 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			743 lines
		
	
	
		
			24 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
# Source Map
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[](https://travis-ci.org/mozilla/source-map)
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[](https://www.npmjs.com/package/source-map)
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This is a library to generate and consume the source map format
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[described here][format].
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[format]: https://docs.google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit
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## Use with Node
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    $ npm install source-map
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## Use on the Web
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    <script src="https://raw.githubusercontent.com/mozilla/source-map/master/dist/source-map.min.js" defer></script>
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--------------------------------------------------------------------------------
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<!-- `npm run toc` to regenerate the Table of Contents -->
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<!-- START doctoc generated TOC please keep comment here to allow auto update -->
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<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
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## Table of Contents
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- [Examples](#examples)
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  - [Consuming a source map](#consuming-a-source-map)
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  - [Generating a source map](#generating-a-source-map)
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    - [With SourceNode (high level API)](#with-sourcenode-high-level-api)
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    - [With SourceMapGenerator (low level API)](#with-sourcemapgenerator-low-level-api)
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- [API](#api)
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  - [SourceMapConsumer](#sourcemapconsumer)
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    - [new SourceMapConsumer(rawSourceMap)](#new-sourcemapconsumerrawsourcemap)
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    - [SourceMapConsumer.prototype.computeColumnSpans()](#sourcemapconsumerprototypecomputecolumnspans)
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    - [SourceMapConsumer.prototype.originalPositionFor(generatedPosition)](#sourcemapconsumerprototypeoriginalpositionforgeneratedposition)
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    - [SourceMapConsumer.prototype.generatedPositionFor(originalPosition)](#sourcemapconsumerprototypegeneratedpositionfororiginalposition)
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    - [SourceMapConsumer.prototype.allGeneratedPositionsFor(originalPosition)](#sourcemapconsumerprototypeallgeneratedpositionsfororiginalposition)
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    - [SourceMapConsumer.prototype.hasContentsOfAllSources()](#sourcemapconsumerprototypehascontentsofallsources)
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    - [SourceMapConsumer.prototype.sourceContentFor(source[, returnNullOnMissing])](#sourcemapconsumerprototypesourcecontentforsource-returnnullonmissing)
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    - [SourceMapConsumer.prototype.eachMapping(callback, context, order)](#sourcemapconsumerprototypeeachmappingcallback-context-order)
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  - [SourceMapGenerator](#sourcemapgenerator)
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    - [new SourceMapGenerator([startOfSourceMap])](#new-sourcemapgeneratorstartofsourcemap)
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    - [SourceMapGenerator.fromSourceMap(sourceMapConsumer)](#sourcemapgeneratorfromsourcemapsourcemapconsumer)
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    - [SourceMapGenerator.prototype.addMapping(mapping)](#sourcemapgeneratorprototypeaddmappingmapping)
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    - [SourceMapGenerator.prototype.setSourceContent(sourceFile, sourceContent)](#sourcemapgeneratorprototypesetsourcecontentsourcefile-sourcecontent)
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    - [SourceMapGenerator.prototype.applySourceMap(sourceMapConsumer[, sourceFile[, sourceMapPath]])](#sourcemapgeneratorprototypeapplysourcemapsourcemapconsumer-sourcefile-sourcemappath)
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    - [SourceMapGenerator.prototype.toString()](#sourcemapgeneratorprototypetostring)
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  - [SourceNode](#sourcenode)
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    - [new SourceNode([line, column, source[, chunk[, name]]])](#new-sourcenodeline-column-source-chunk-name)
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    - [SourceNode.fromStringWithSourceMap(code, sourceMapConsumer[, relativePath])](#sourcenodefromstringwithsourcemapcode-sourcemapconsumer-relativepath)
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    - [SourceNode.prototype.add(chunk)](#sourcenodeprototypeaddchunk)
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    - [SourceNode.prototype.prepend(chunk)](#sourcenodeprototypeprependchunk)
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    - [SourceNode.prototype.setSourceContent(sourceFile, sourceContent)](#sourcenodeprototypesetsourcecontentsourcefile-sourcecontent)
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    - [SourceNode.prototype.walk(fn)](#sourcenodeprototypewalkfn)
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    - [SourceNode.prototype.walkSourceContents(fn)](#sourcenodeprototypewalksourcecontentsfn)
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    - [SourceNode.prototype.join(sep)](#sourcenodeprototypejoinsep)
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    - [SourceNode.prototype.replaceRight(pattern, replacement)](#sourcenodeprototypereplacerightpattern-replacement)
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    - [SourceNode.prototype.toString()](#sourcenodeprototypetostring)
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    - [SourceNode.prototype.toStringWithSourceMap([startOfSourceMap])](#sourcenodeprototypetostringwithsourcemapstartofsourcemap)
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<!-- END doctoc generated TOC please keep comment here to allow auto update -->
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## Examples
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### Consuming a source map
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```js
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var rawSourceMap = {
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  version: 3,
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  file: 'min.js',
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  names: ['bar', 'baz', 'n'],
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  sources: ['one.js', 'two.js'],
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  sourceRoot: 'http://example.com/www/js/',
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  mappings: 'CAAC,IAAI,IAAM,SAAUA,GAClB,OAAOC,IAAID;CCDb,IAAI,IAAM,SAAUE,GAClB,OAAOA'
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};
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var smc = new SourceMapConsumer(rawSourceMap);
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console.log(smc.sources);
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// [ 'http://example.com/www/js/one.js',
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//   'http://example.com/www/js/two.js' ]
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console.log(smc.originalPositionFor({
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  line: 2,
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  column: 28
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}));
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// { source: 'http://example.com/www/js/two.js',
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//   line: 2,
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//   column: 10,
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//   name: 'n' }
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console.log(smc.generatedPositionFor({
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  source: 'http://example.com/www/js/two.js',
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  line: 2,
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  column: 10
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}));
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// { line: 2, column: 28 }
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smc.eachMapping(function (m) {
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  // ...
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});
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```
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### Generating a source map
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In depth guide:
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[**Compiling to JavaScript, and Debugging with Source Maps**](https://hacks.mozilla.org/2013/05/compiling-to-javascript-and-debugging-with-source-maps/)
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#### With SourceNode (high level API)
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```js
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function compile(ast) {
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  switch (ast.type) {
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  case 'BinaryExpression':
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    return new SourceNode(
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      ast.location.line,
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      ast.location.column,
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      ast.location.source,
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      [compile(ast.left), " + ", compile(ast.right)]
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    );
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  case 'Literal':
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    return new SourceNode(
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      ast.location.line,
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      ast.location.column,
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      ast.location.source,
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      String(ast.value)
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    );
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  // ...
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  default:
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    throw new Error("Bad AST");
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  }
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}
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var ast = parse("40 + 2", "add.js");
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console.log(compile(ast).toStringWithSourceMap({
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  file: 'add.js'
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}));
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// { code: '40 + 2',
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//   map: [object SourceMapGenerator] }
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```
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#### With SourceMapGenerator (low level API)
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```js
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var map = new SourceMapGenerator({
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  file: "source-mapped.js"
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});
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map.addMapping({
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  generated: {
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    line: 10,
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    column: 35
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  },
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  source: "foo.js",
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  original: {
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    line: 33,
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    column: 2
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  },
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  name: "christopher"
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});
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console.log(map.toString());
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// '{"version":3,"file":"source-mapped.js","sources":["foo.js"],"names":["christopher"],"mappings":";;;;;;;;;mCAgCEA"}'
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```
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## API
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Get a reference to the module:
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```js
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// Node.js
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var sourceMap = require('source-map');
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// Browser builds
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var sourceMap = window.sourceMap;
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// Inside Firefox
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const sourceMap = require("devtools/toolkit/sourcemap/source-map.js");
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```
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### SourceMapConsumer
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A SourceMapConsumer instance represents a parsed source map which we can query
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for information about the original file positions by giving it a file position
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in the generated source.
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#### new SourceMapConsumer(rawSourceMap)
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The only parameter is the raw source map (either as a string which can be
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`JSON.parse`'d, or an object). According to the spec, source maps have the
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following attributes:
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* `version`: Which version of the source map spec this map is following.
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* `sources`: An array of URLs to the original source files.
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* `names`: An array of identifiers which can be referenced by individual
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  mappings.
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* `sourceRoot`: Optional. The URL root from which all sources are relative.
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* `sourcesContent`: Optional. An array of contents of the original source files.
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* `mappings`: A string of base64 VLQs which contain the actual mappings.
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* `file`: Optional. The generated filename this source map is associated with.
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```js
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var consumer = new sourceMap.SourceMapConsumer(rawSourceMapJsonData);
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```
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#### SourceMapConsumer.prototype.computeColumnSpans()
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Compute the last column for each generated mapping. The last column is
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inclusive.
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```js
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// Before:
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consumer.allGeneratedPositionsFor({ line: 2, source: "foo.coffee" })
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// [ { line: 2,
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//     column: 1 },
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//   { line: 2,
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//     column: 10 },
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//   { line: 2,
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//     column: 20 } ]
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consumer.computeColumnSpans();
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// After:
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consumer.allGeneratedPositionsFor({ line: 2, source: "foo.coffee" })
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// [ { line: 2,
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//     column: 1,
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//     lastColumn: 9 },
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//   { line: 2,
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//     column: 10,
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//     lastColumn: 19 },
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//   { line: 2,
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//     column: 20,
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//     lastColumn: Infinity } ]
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```
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#### SourceMapConsumer.prototype.originalPositionFor(generatedPosition)
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Returns the original source, line, and column information for the generated
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source's line and column positions provided. The only argument is an object with
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the following properties:
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* `line`: The line number in the generated source.  Line numbers in
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  this library are 1-based (note that the underlying source map
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  specification uses 0-based line numbers -- this library handles the
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  translation).
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* `column`: The column number in the generated source.  Column numbers
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  in this library are 0-based.
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* `bias`: Either `SourceMapConsumer.GREATEST_LOWER_BOUND` or
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  `SourceMapConsumer.LEAST_UPPER_BOUND`. Specifies whether to return the closest
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  element that is smaller than or greater than the one we are searching for,
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  respectively, if the exact element cannot be found.  Defaults to
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  `SourceMapConsumer.GREATEST_LOWER_BOUND`.
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and an object is returned with the following properties:
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* `source`: The original source file, or null if this information is not
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  available.
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* `line`: The line number in the original source, or null if this information is
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  not available.  The line number is 1-based.
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* `column`: The column number in the original source, or null if this
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  information is not available.  The column number is 0-based.
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* `name`: The original identifier, or null if this information is not available.
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```js
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consumer.originalPositionFor({ line: 2, column: 10 })
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// { source: 'foo.coffee',
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//   line: 2,
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//   column: 2,
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//   name: null }
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consumer.originalPositionFor({ line: 99999999999999999, column: 999999999999999 })
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// { source: null,
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//   line: null,
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//   column: null,
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//   name: null }
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```
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#### SourceMapConsumer.prototype.generatedPositionFor(originalPosition)
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Returns the generated line and column information for the original source,
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line, and column positions provided. The only argument is an object with
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the following properties:
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* `source`: The filename of the original source.
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* `line`: The line number in the original source.  The line number is
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  1-based.
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* `column`: The column number in the original source.  The column
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  number is 0-based.
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and an object is returned with the following properties:
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* `line`: The line number in the generated source, or null.  The line
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  number is 1-based.
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* `column`: The column number in the generated source, or null.  The
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  column number is 0-based.
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```js
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consumer.generatedPositionFor({ source: "example.js", line: 2, column: 10 })
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// { line: 1,
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//   column: 56 }
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```
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#### SourceMapConsumer.prototype.allGeneratedPositionsFor(originalPosition)
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Returns all generated line and column information for the original source, line,
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and column provided. If no column is provided, returns all mappings
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corresponding to a either the line we are searching for or the next closest line
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that has any mappings. Otherwise, returns all mappings corresponding to the
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given line and either the column we are searching for or the next closest column
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that has any offsets.
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The only argument is an object with the following properties:
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* `source`: The filename of the original source.
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* `line`: The line number in the original source.  The line number is
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  1-based.
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* `column`: Optional. The column number in the original source.  The
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  column number is 0-based.
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and an array of objects is returned, each with the following properties:
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* `line`: The line number in the generated source, or null.  The line
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  number is 1-based.
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* `column`: The column number in the generated source, or null.  The
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  column number is 0-based.
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```js
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consumer.allGeneratedpositionsfor({ line: 2, source: "foo.coffee" })
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// [ { line: 2,
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//     column: 1 },
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//   { line: 2,
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//     column: 10 },
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//   { line: 2,
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//     column: 20 } ]
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```
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#### SourceMapConsumer.prototype.hasContentsOfAllSources()
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Return true if we have the embedded source content for every source listed in
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the source map, false otherwise.
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In other words, if this method returns `true`, then
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`consumer.sourceContentFor(s)` will succeed for every source `s` in
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`consumer.sources`.
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```js
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// ...
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if (consumer.hasContentsOfAllSources()) {
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  consumerReadyCallback(consumer);
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} else {
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  fetchSources(consumer, consumerReadyCallback);
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}
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// ...
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```
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#### SourceMapConsumer.prototype.sourceContentFor(source[, returnNullOnMissing])
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Returns the original source content for the source provided. The only
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argument is the URL of the original source file.
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If the source content for the given source is not found, then an error is
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thrown. Optionally, pass `true` as the second param to have `null` returned
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instead.
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```js
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consumer.sources
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// [ "my-cool-lib.clj" ]
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consumer.sourceContentFor("my-cool-lib.clj")
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// "..."
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consumer.sourceContentFor("this is not in the source map");
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// Error: "this is not in the source map" is not in the source map
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consumer.sourceContentFor("this is not in the source map", true);
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// null
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```
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#### SourceMapConsumer.prototype.eachMapping(callback, context, order)
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Iterate over each mapping between an original source/line/column and a
 | 
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generated line/column in this source map.
 | 
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						|
* `callback`: The function that is called with each mapping. Mappings have the
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  form `{ source, generatedLine, generatedColumn, originalLine, originalColumn,
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  name }`
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						|
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						|
* `context`: Optional. If specified, this object will be the value of `this`
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						|
  every time that `callback` is called.
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						|
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						|
* `order`: Either `SourceMapConsumer.GENERATED_ORDER` or
 | 
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  `SourceMapConsumer.ORIGINAL_ORDER`. Specifies whether you want to iterate over
 | 
						|
  the mappings sorted by the generated file's line/column order or the
 | 
						|
  original's source/line/column order, respectively. Defaults to
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						|
  `SourceMapConsumer.GENERATED_ORDER`.
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						|
```js
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consumer.eachMapping(function (m) { console.log(m); })
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// ...
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						|
// { source: 'illmatic.js',
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//   generatedLine: 1,
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//   generatedColumn: 0,
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//   originalLine: 1,
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//   originalColumn: 0,
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//   name: null }
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// { source: 'illmatic.js',
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//   generatedLine: 2,
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						|
//   generatedColumn: 0,
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						|
//   originalLine: 2,
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						|
//   originalColumn: 0,
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						|
//   name: null }
 | 
						|
// ...
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						|
```
 | 
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### SourceMapGenerator
 | 
						|
 | 
						|
An instance of the SourceMapGenerator represents a source map which is being
 | 
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built incrementally.
 | 
						|
 | 
						|
#### new SourceMapGenerator([startOfSourceMap])
 | 
						|
 | 
						|
You may pass an object with the following properties:
 | 
						|
 | 
						|
* `file`: The filename of the generated source that this source map is
 | 
						|
  associated with.
 | 
						|
 | 
						|
* `sourceRoot`: A root for all relative URLs in this source map.
 | 
						|
 | 
						|
* `skipValidation`: Optional. When `true`, disables validation of mappings as
 | 
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  they are added. This can improve performance but should be used with
 | 
						|
  discretion, as a last resort. Even then, one should avoid using this flag when
 | 
						|
  running tests, if possible.
 | 
						|
 | 
						|
```js
 | 
						|
var generator = new sourceMap.SourceMapGenerator({
 | 
						|
  file: "my-generated-javascript-file.js",
 | 
						|
  sourceRoot: "http://example.com/app/js/"
 | 
						|
});
 | 
						|
```
 | 
						|
 | 
						|
#### SourceMapGenerator.fromSourceMap(sourceMapConsumer)
 | 
						|
 | 
						|
Creates a new `SourceMapGenerator` from an existing `SourceMapConsumer` instance.
 | 
						|
 | 
						|
* `sourceMapConsumer` The SourceMap.
 | 
						|
 | 
						|
```js
 | 
						|
var generator = sourceMap.SourceMapGenerator.fromSourceMap(consumer);
 | 
						|
```
 | 
						|
 | 
						|
#### SourceMapGenerator.prototype.addMapping(mapping)
 | 
						|
 | 
						|
Add a single mapping from original source line and column to the generated
 | 
						|
source's line and column for this source map being created. The mapping object
 | 
						|
should have the following properties:
 | 
						|
 | 
						|
* `generated`: An object with the generated line and column positions.
 | 
						|
 | 
						|
* `original`: An object with the original line and column positions.
 | 
						|
 | 
						|
* `source`: The original source file (relative to the sourceRoot).
 | 
						|
 | 
						|
* `name`: An optional original token name for this mapping.
 | 
						|
 | 
						|
```js
 | 
						|
generator.addMapping({
 | 
						|
  source: "module-one.scm",
 | 
						|
  original: { line: 128, column: 0 },
 | 
						|
  generated: { line: 3, column: 456 }
 | 
						|
})
 | 
						|
```
 | 
						|
 | 
						|
#### SourceMapGenerator.prototype.setSourceContent(sourceFile, sourceContent)
 | 
						|
 | 
						|
Set the source content for an original source file.
 | 
						|
 | 
						|
* `sourceFile` the URL of the original source file.
 | 
						|
 | 
						|
* `sourceContent` the content of the source file.
 | 
						|
 | 
						|
```js
 | 
						|
generator.setSourceContent("module-one.scm",
 | 
						|
                           fs.readFileSync("path/to/module-one.scm"))
 | 
						|
```
 | 
						|
 | 
						|
#### SourceMapGenerator.prototype.applySourceMap(sourceMapConsumer[, sourceFile[, sourceMapPath]])
 | 
						|
 | 
						|
Applies a SourceMap for a source file to the SourceMap.
 | 
						|
Each mapping to the supplied source file is rewritten using the
 | 
						|
supplied SourceMap. Note: The resolution for the resulting mappings
 | 
						|
is the minimum of this map and the supplied map.
 | 
						|
 | 
						|
* `sourceMapConsumer`: The SourceMap to be applied.
 | 
						|
 | 
						|
* `sourceFile`: Optional. The filename of the source file.
 | 
						|
  If omitted, sourceMapConsumer.file will be used, if it exists.
 | 
						|
  Otherwise an error will be thrown.
 | 
						|
 | 
						|
* `sourceMapPath`: Optional. The dirname of the path to the SourceMap
 | 
						|
  to be applied. If relative, it is relative to the SourceMap.
 | 
						|
 | 
						|
  This parameter is needed when the two SourceMaps aren't in the same
 | 
						|
  directory, and the SourceMap to be applied contains relative source
 | 
						|
  paths. If so, those relative source paths need to be rewritten
 | 
						|
  relative to the SourceMap.
 | 
						|
 | 
						|
  If omitted, it is assumed that both SourceMaps are in the same directory,
 | 
						|
  thus not needing any rewriting. (Supplying `'.'` has the same effect.)
 | 
						|
 | 
						|
#### SourceMapGenerator.prototype.toString()
 | 
						|
 | 
						|
Renders the source map being generated to a string.
 | 
						|
 | 
						|
```js
 | 
						|
generator.toString()
 | 
						|
// '{"version":3,"sources":["module-one.scm"],"names":[],"mappings":"...snip...","file":"my-generated-javascript-file.js","sourceRoot":"http://example.com/app/js/"}'
 | 
						|
```
 | 
						|
 | 
						|
### SourceNode
 | 
						|
 | 
						|
SourceNodes provide a way to abstract over interpolating and/or concatenating
 | 
						|
snippets of generated JavaScript source code, while maintaining the line and
 | 
						|
column information associated between those snippets and the original source
 | 
						|
code. This is useful as the final intermediate representation a compiler might
 | 
						|
use before outputting the generated JS and source map.
 | 
						|
 | 
						|
#### new SourceNode([line, column, source[, chunk[, name]]])
 | 
						|
 | 
						|
* `line`: The original line number associated with this source node, or null if
 | 
						|
  it isn't associated with an original line.  The line number is 1-based.
 | 
						|
 | 
						|
* `column`: The original column number associated with this source node, or null
 | 
						|
  if it isn't associated with an original column.  The column number
 | 
						|
  is 0-based.
 | 
						|
 | 
						|
* `source`: The original source's filename; null if no filename is provided.
 | 
						|
 | 
						|
* `chunk`: Optional. Is immediately passed to `SourceNode.prototype.add`, see
 | 
						|
  below.
 | 
						|
 | 
						|
* `name`: Optional. The original identifier.
 | 
						|
 | 
						|
```js
 | 
						|
var node = new SourceNode(1, 2, "a.cpp", [
 | 
						|
  new SourceNode(3, 4, "b.cpp", "extern int status;\n"),
 | 
						|
  new SourceNode(5, 6, "c.cpp", "std::string* make_string(size_t n);\n"),
 | 
						|
  new SourceNode(7, 8, "d.cpp", "int main(int argc, char** argv) {}\n"),
 | 
						|
]);
 | 
						|
```
 | 
						|
 | 
						|
#### SourceNode.fromStringWithSourceMap(code, sourceMapConsumer[, relativePath])
 | 
						|
 | 
						|
Creates a SourceNode from generated code and a SourceMapConsumer.
 | 
						|
 | 
						|
* `code`: The generated code
 | 
						|
 | 
						|
* `sourceMapConsumer` The SourceMap for the generated code
 | 
						|
 | 
						|
* `relativePath` The optional path that relative sources in `sourceMapConsumer`
 | 
						|
  should be relative to.
 | 
						|
 | 
						|
```js
 | 
						|
var consumer = new SourceMapConsumer(fs.readFileSync("path/to/my-file.js.map", "utf8"));
 | 
						|
var node = SourceNode.fromStringWithSourceMap(fs.readFileSync("path/to/my-file.js"),
 | 
						|
                                              consumer);
 | 
						|
```
 | 
						|
 | 
						|
#### SourceNode.prototype.add(chunk)
 | 
						|
 | 
						|
Add a chunk of generated JS to this source node.
 | 
						|
 | 
						|
* `chunk`: A string snippet of generated JS code, another instance of
 | 
						|
   `SourceNode`, or an array where each member is one of those things.
 | 
						|
 | 
						|
```js
 | 
						|
node.add(" + ");
 | 
						|
node.add(otherNode);
 | 
						|
node.add([leftHandOperandNode, " + ", rightHandOperandNode]);
 | 
						|
```
 | 
						|
 | 
						|
#### SourceNode.prototype.prepend(chunk)
 | 
						|
 | 
						|
Prepend a chunk of generated JS to this source node.
 | 
						|
 | 
						|
* `chunk`: A string snippet of generated JS code, another instance of
 | 
						|
   `SourceNode`, or an array where each member is one of those things.
 | 
						|
 | 
						|
```js
 | 
						|
node.prepend("/** Build Id: f783haef86324gf **/\n\n");
 | 
						|
```
 | 
						|
 | 
						|
#### SourceNode.prototype.setSourceContent(sourceFile, sourceContent)
 | 
						|
 | 
						|
Set the source content for a source file. This will be added to the
 | 
						|
`SourceMap` in the `sourcesContent` field.
 | 
						|
 | 
						|
* `sourceFile`: The filename of the source file
 | 
						|
 | 
						|
* `sourceContent`: The content of the source file
 | 
						|
 | 
						|
```js
 | 
						|
node.setSourceContent("module-one.scm",
 | 
						|
                      fs.readFileSync("path/to/module-one.scm"))
 | 
						|
```
 | 
						|
 | 
						|
#### SourceNode.prototype.walk(fn)
 | 
						|
 | 
						|
Walk over the tree of JS snippets in this node and its children. The walking
 | 
						|
function is called once for each snippet of JS and is passed that snippet and
 | 
						|
the its original associated source's line/column location.
 | 
						|
 | 
						|
* `fn`: The traversal function.
 | 
						|
 | 
						|
```js
 | 
						|
var node = new SourceNode(1, 2, "a.js", [
 | 
						|
  new SourceNode(3, 4, "b.js", "uno"),
 | 
						|
  "dos",
 | 
						|
  [
 | 
						|
    "tres",
 | 
						|
    new SourceNode(5, 6, "c.js", "quatro")
 | 
						|
  ]
 | 
						|
]);
 | 
						|
 | 
						|
node.walk(function (code, loc) { console.log("WALK:", code, loc); })
 | 
						|
// WALK: uno { source: 'b.js', line: 3, column: 4, name: null }
 | 
						|
// WALK: dos { source: 'a.js', line: 1, column: 2, name: null }
 | 
						|
// WALK: tres { source: 'a.js', line: 1, column: 2, name: null }
 | 
						|
// WALK: quatro { source: 'c.js', line: 5, column: 6, name: null }
 | 
						|
```
 | 
						|
 | 
						|
#### SourceNode.prototype.walkSourceContents(fn)
 | 
						|
 | 
						|
Walk over the tree of SourceNodes. The walking function is called for each
 | 
						|
source file content and is passed the filename and source content.
 | 
						|
 | 
						|
* `fn`: The traversal function.
 | 
						|
 | 
						|
```js
 | 
						|
var a = new SourceNode(1, 2, "a.js", "generated from a");
 | 
						|
a.setSourceContent("a.js", "original a");
 | 
						|
var b = new SourceNode(1, 2, "b.js", "generated from b");
 | 
						|
b.setSourceContent("b.js", "original b");
 | 
						|
var c = new SourceNode(1, 2, "c.js", "generated from c");
 | 
						|
c.setSourceContent("c.js", "original c");
 | 
						|
 | 
						|
var node = new SourceNode(null, null, null, [a, b, c]);
 | 
						|
node.walkSourceContents(function (source, contents) { console.log("WALK:", source, ":", contents); })
 | 
						|
// WALK: a.js : original a
 | 
						|
// WALK: b.js : original b
 | 
						|
// WALK: c.js : original c
 | 
						|
```
 | 
						|
 | 
						|
#### SourceNode.prototype.join(sep)
 | 
						|
 | 
						|
Like `Array.prototype.join` except for SourceNodes. Inserts the separator
 | 
						|
between each of this source node's children.
 | 
						|
 | 
						|
* `sep`: The separator.
 | 
						|
 | 
						|
```js
 | 
						|
var lhs = new SourceNode(1, 2, "a.rs", "my_copy");
 | 
						|
var operand = new SourceNode(3, 4, "a.rs", "=");
 | 
						|
var rhs = new SourceNode(5, 6, "a.rs", "orig.clone()");
 | 
						|
 | 
						|
var node = new SourceNode(null, null, null, [ lhs, operand, rhs ]);
 | 
						|
var joinedNode = node.join(" ");
 | 
						|
```
 | 
						|
 | 
						|
#### SourceNode.prototype.replaceRight(pattern, replacement)
 | 
						|
 | 
						|
Call `String.prototype.replace` on the very right-most source snippet. Useful
 | 
						|
for trimming white space from the end of a source node, etc.
 | 
						|
 | 
						|
* `pattern`: The pattern to replace.
 | 
						|
 | 
						|
* `replacement`: The thing to replace the pattern with.
 | 
						|
 | 
						|
```js
 | 
						|
// Trim trailing white space.
 | 
						|
node.replaceRight(/\s*$/, "");
 | 
						|
```
 | 
						|
 | 
						|
#### SourceNode.prototype.toString()
 | 
						|
 | 
						|
Return the string representation of this source node. Walks over the tree and
 | 
						|
concatenates all the various snippets together to one string.
 | 
						|
 | 
						|
```js
 | 
						|
var node = new SourceNode(1, 2, "a.js", [
 | 
						|
  new SourceNode(3, 4, "b.js", "uno"),
 | 
						|
  "dos",
 | 
						|
  [
 | 
						|
    "tres",
 | 
						|
    new SourceNode(5, 6, "c.js", "quatro")
 | 
						|
  ]
 | 
						|
]);
 | 
						|
 | 
						|
node.toString()
 | 
						|
// 'unodostresquatro'
 | 
						|
```
 | 
						|
 | 
						|
#### SourceNode.prototype.toStringWithSourceMap([startOfSourceMap])
 | 
						|
 | 
						|
Returns the string representation of this tree of source nodes, plus a
 | 
						|
SourceMapGenerator which contains all the mappings between the generated and
 | 
						|
original sources.
 | 
						|
 | 
						|
The arguments are the same as those to `new SourceMapGenerator`.
 | 
						|
 | 
						|
```js
 | 
						|
var node = new SourceNode(1, 2, "a.js", [
 | 
						|
  new SourceNode(3, 4, "b.js", "uno"),
 | 
						|
  "dos",
 | 
						|
  [
 | 
						|
    "tres",
 | 
						|
    new SourceNode(5, 6, "c.js", "quatro")
 | 
						|
  ]
 | 
						|
]);
 | 
						|
 | 
						|
node.toStringWithSourceMap({ file: "my-output-file.js" })
 | 
						|
// { code: 'unodostresquatro',
 | 
						|
//   map: [object SourceMapGenerator] }
 | 
						|
```
 |