name : source-map-generator.js /* -*- Mode: js; js-indent-level: 2; -*- */ /* * Copyright 2011 Mozilla Foundation and contributors * Licensed under the New BSD license. See LICENSE or: * http://opensource.org/licenses/BSD-3-Clause */ var base64VLQ = require('./base64-vlq'); var util = require('./util'); var ArraySet = require('./array-set').ArraySet; var MappingList = require('./mapping-list').MappingList; /** * An instance of the SourceMapGenerator represents a source map which is * being built incrementally. You may pass an object with the following * properties: * * - file: The filename of the generated source. * - sourceRoot: A root for all relative URLs in this source map. */ function SourceMapGenerator(aArgs) { if (!aArgs) { aArgs = {}; } this._file = util.getArg(aArgs, 'file', null); this._sourceRoot = util.getArg(aArgs, 'sourceRoot', null); this._skipValidation = util.getArg(aArgs, 'skipValidation', false); this._sources = new ArraySet(); this._names = new ArraySet(); this._mappings = new MappingList(); this._sourcesContents = null; } SourceMapGenerator.prototype._version = 3; /** * Creates a new SourceMapGenerator based on a SourceMapConsumer * * @param aSourceMapConsumer The SourceMap. */ SourceMapGenerator.fromSourceMap = function SourceMapGenerator_fromSourceMap(aSourceMapConsumer) { var sourceRoot = aSourceMapConsumer.sourceRoot; var generator = new SourceMapGenerator({ file: aSourceMapConsumer.file, sourceRoot: sourceRoot }); aSourceMapConsumer.eachMapping(function (mapping) { var newMapping = { generated: { line: mapping.generatedLine, column: mapping.generatedColumn } }; if (mapping.source != null) { newMapping.source = mapping.source; if (sourceRoot != null) { newMapping.source = util.relative(sourceRoot, newMapping.source); } newMapping.original = { line: mapping.originalLine, column: mapping.originalColumn }; if (mapping.name != null) { newMapping.name = mapping.name; } } generator.addMapping(newMapping); }); aSourceMapConsumer.sources.forEach(function (sourceFile) { var sourceRelative = sourceFile; if (sourceRoot !== null) { sourceRelative = util.relative(sourceRoot, sourceFile); } if (!generator._sources.has(sourceRelative)) { generator._sources.add(sourceRelative); } var content = aSourceMapConsumer.sourceContentFor(sourceFile); if (content != null) { generator.setSourceContent(sourceFile, content); } }); return generator; }; /** * 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. */ SourceMapGenerator.prototype.addMapping = function SourceMapGenerator_addMapping(aArgs) { var generated = util.getArg(aArgs, 'generated'); var original = util.getArg(aArgs, 'original', null); var source = util.getArg(aArgs, 'source', null); var name = util.getArg(aArgs, 'name', null); if (!this._skipValidation) { this._validateMapping(generated, original, source, name); } if (source != null) { source = String(source); if (!this._sources.has(source)) { this._sources.add(source); } } if (name != null) { name = String(name); if (!this._names.has(name)) { this._names.add(name); } } this._mappings.add({ generatedLine: generated.line, generatedColumn: generated.column, originalLine: original != null && original.line, originalColumn: original != null && original.column, source: source, name: name }); }; /** * Set the source content for a source file. */ SourceMapGenerator.prototype.setSourceContent = function SourceMapGenerator_setSourceContent(aSourceFile, aSourceContent) { var source = aSourceFile; if (this._sourceRoot != null) { source = util.relative(this._sourceRoot, source); } if (aSourceContent != null) { // Add the source content to the _sourcesContents map. // Create a new _sourcesContents map if the property is null. if (!this._sourcesContents) { this._sourcesContents = Object.create(null); } this._sourcesContents[util.toSetString(source)] = aSourceContent; } else if (this._sourcesContents) { // Remove the source file from the _sourcesContents map. // If the _sourcesContents map is empty, set the property to null. delete this._sourcesContents[util.toSetString(source)]; if (Object.keys(this._sourcesContents).length === 0) { this._sourcesContents = null; } } }; /** * Applies the mappings of a sub-source-map for a specific source file to the * source map being generated. Each mapping to the supplied source file is * rewritten using the supplied source map. Note: The resolution for the * resulting mappings is the minimium of this map and the supplied map. * * @param aSourceMapConsumer The source map to be applied. * @param aSourceFile Optional. The filename of the source file. * If omitted, SourceMapConsumer's file property will be used. * @param aSourceMapPath Optional. The dirname of the path to the source map * to be applied. If relative, it is relative to the SourceMapConsumer. * This parameter is needed when the two source maps aren't in the same * directory, and the source map to be applied contains relative source * paths. If so, those relative source paths need to be rewritten * relative to the SourceMapGenerator. */ SourceMapGenerator.prototype.applySourceMap = function SourceMapGenerator_applySourceMap(aSourceMapConsumer, aSourceFile, aSourceMapPath) { var sourceFile = aSourceFile; // If aSourceFile is omitted, we will use the file property of the SourceMap if (aSourceFile == null) { if (aSourceMapConsumer.file == null) { throw new Error( 'SourceMapGenerator.prototype.applySourceMap requires either an explicit source file, ' + 'or the source map\'s "file" property. Both were omitted.' ); } sourceFile = aSourceMapConsumer.file; } var sourceRoot = this._sourceRoot; // Make "sourceFile" relative if an absolute Url is passed. if (sourceRoot != null) { sourceFile = util.relative(sourceRoot, sourceFile); } // Applying the SourceMap can add and remove items from the sources and // the names array. var newSources = new ArraySet(); var newNames = new ArraySet(); // Find mappings for the "sourceFile" this._mappings.unsortedForEach(function (mapping) { if (mapping.source === sourceFile && mapping.originalLine != null) { // Check if it can be mapped by the source map, then update the mapping. var original = aSourceMapConsumer.originalPositionFor({ line: mapping.originalLine, column: mapping.originalColumn }); if (original.source != null) { // Copy mapping mapping.source = original.source; if (aSourceMapPath != null) { mapping.source = util.join(aSourceMapPath, mapping.source) } if (sourceRoot != null) { mapping.source = util.relative(sourceRoot, mapping.source); } mapping.originalLine = original.line; mapping.originalColumn = original.column; if (original.name != null) { mapping.name = original.name; } } } var source = mapping.source; if (source != null && !newSources.has(source)) { newSources.add(source); } var name = mapping.name; if (name != null && !newNames.has(name)) { newNames.add(name); } }, this); this._sources = newSources; this._names = newNames; // Copy sourcesContents of applied map. aSourceMapConsumer.sources.forEach(function (sourceFile) { var content = aSourceMapConsumer.sourceContentFor(sourceFile); if (content != null) { if (aSourceMapPath != null) { sourceFile = util.join(aSourceMapPath, sourceFile); } if (sourceRoot != null) { sourceFile = util.relative(sourceRoot, sourceFile); } this.setSourceContent(sourceFile, content); } }, this); }; /** * A mapping can have one of the three levels of data: * * 1. Just the generated position. * 2. The Generated position, original position, and original source. * 3. Generated and original position, original source, as well as a name * token. * * To maintain consistency, we validate that any new mapping being added falls * in to one of these categories. */ SourceMapGenerator.prototype._validateMapping = function SourceMapGenerator_validateMapping(aGenerated, aOriginal, aSource, aName) { // When aOriginal is truthy but has empty values for .line and .column, // it is most likely a programmer error. In this case we throw a very // specific error message to try to guide them the right way. // For example: https://github.com/Polymer/polymer-bundler/pull/519 if (aOriginal && typeof aOriginal.line !== 'number' && typeof aOriginal.column !== 'number') { throw new Error( 'original.line and original.column are not numbers -- you probably meant to omit ' + 'the original mapping entirely and only map the generated position. If so, pass ' + 'null for the original mapping instead of an object with empty or null values.' ); } if (aGenerated && 'line' in aGenerated && 'column' in aGenerated && aGenerated.line > 0 && aGenerated.column >= 0 && !aOriginal && !aSource && !aName) { // Case 1. return; } else if (aGenerated && 'line' in aGenerated && 'column' in aGenerated && aOriginal && 'line' in aOriginal && 'column' in aOriginal && aGenerated.line > 0 && aGenerated.column >= 0 && aOriginal.line > 0 && aOriginal.column >= 0 && aSource) { // Cases 2 and 3. return; } else { throw new Error('Invalid mapping: ' + JSON.stringify({ generated: aGenerated, source: aSource, original: aOriginal, name: aName })); } }; /** * Serialize the accumulated mappings in to the stream of base 64 VLQs * specified by the source map format. */ SourceMapGenerator.prototype._serializeMappings = function SourceMapGenerator_serializeMappings() { var previousGeneratedColumn = 0; var previousGeneratedLine = 1; var previousOriginalColumn = 0; var previousOriginalLine = 0; var previousName = 0; var previousSource = 0; var result = ''; var next; var mapping; var nameIdx; var sourceIdx; var mappings = this._mappings.toArray(); for (var i = 0, len = mappings.length; i < len; i++) { mapping = mappings[i]; next = '' if (mapping.generatedLine !== previousGeneratedLine) { previousGeneratedColumn = 0; while (mapping.generatedLine !== previousGeneratedLine) { next += ';'; previousGeneratedLine++; } } else { if (i > 0) { if (!util.compareByGeneratedPositionsInflated(mapping, mappings[i - 1])) { continue; } next += ','; } } next += base64VLQ.encode(mapping.generatedColumn - previousGeneratedColumn); previousGeneratedColumn = mapping.generatedColumn; if (mapping.source != null) { sourceIdx = this._sources.indexOf(mapping.source); next += base64VLQ.encode(sourceIdx - previousSource); previousSource = sourceIdx; // lines are stored 0-based in SourceMap spec version 3 next += base64VLQ.encode(mapping.originalLine - 1 - previousOriginalLine); previousOriginalLine = mapping.originalLine - 1; next += base64VLQ.encode(mapping.originalColumn - previousOriginalColumn); previousOriginalColumn = mapping.originalColumn; if (mapping.name != null) { nameIdx = this._names.indexOf(mapping.name); next += base64VLQ.encode(nameIdx - previousName); previousName = nameIdx; } } result += next; } return result; }; SourceMapGenerator.prototype._generateSourcesContent = function SourceMapGenerator_generateSourcesContent(aSources, aSourceRoot) { return aSources.map(function (source) { if (!this._sourcesContents) { return null; } if (aSourceRoot != null) { source = util.relative(aSourceRoot, source); } var key = util.toSetString(source); return Object.prototype.hasOwnProperty.call(this._sourcesContents, key) ? this._sourcesContents[key] : null; }, this); }; /** * Externalize the source map. */ SourceMapGenerator.prototype.toJSON = function SourceMapGenerator_toJSON() { var map = { version: this._version, sources: this._sources.toArray(), names: this._names.toArray(), mappings: this._serializeMappings() }; if (this._file != null) { map.file = this._file; } if (this._sourceRoot != null) { map.sourceRoot = this._sourceRoot; } if (this._sourcesContents) { map.sourcesContent = this._generateSourcesContent(map.sources, map.sourceRoot); } return map; }; /** * Render the source map being generated to a string. */ SourceMapGenerator.prototype.toString = function SourceMapGenerator_toString() { return JSON.stringify(this.toJSON()); }; exports.SourceMapGenerator = SourceMapGenerator;