TypeScript SourceMapGenerator.fromSourceMap方法代碼示例

export function mergeSourceMaps(
    oldMap: RawSourceMap | null, newMap: RawSourceMap): SourceMapConverter {
  if (!oldMap) {
    return fromObject(newMap);
  }
  const oldMapConsumer = new SourceMapConsumer(oldMap);
  const newMapConsumer = new SourceMapConsumer(newMap);
  const mergedMapGenerator = SourceMapGenerator.fromSourceMap(newMapConsumer);
  mergedMapGenerator.applySourceMap(oldMapConsumer);
  const merged = fromJSON(mergedMapGenerator.toString());
  return merged;
}

function combineSourceMaps(
    program: ts.Program, filePath: string, tscSourceMapText: string): string {
  const tscSourceMap = parseSourceMap(tscSourceMapText);
  let tscSourceMapGenerator: SourceMapGenerator|undefined;
  for (const sourceFileName of tscSourceMap.sources) {
    const sourceFile = program.getSourceFile(sourceFileName);
    if (!sourceFile || !containsInlineSourceMap(sourceFile.text)) {
      continue;
    }
    const preexistingSourceMapText = extractInlineSourceMap(sourceFile.text);
    if (!tscSourceMapGenerator) {
      tscSourceMapGenerator = SourceMapGenerator.fromSourceMap(new SourceMapConsumer(tscSourceMap));
    }
    tscSourceMapGenerator.applySourceMap(
        new SourceMapConsumer(parseSourceMap(preexistingSourceMapText, sourceFileName)));
  }
  return tscSourceMapGenerator ? tscSourceMapGenerator.toString() : tscSourceMapText;
}

export default function buildOptimizerLoader
  (this: webpack.loader.LoaderContext, content: string, previousSourceMap: RawSourceMap) {
  this.cacheable();
  const options: BuildOptimizerLoaderOptions = loaderUtils.getOptions(this) || {};

  // Make up names of the intermediate files so we can chain the sourcemaps.
  const inputFilePath = this.resourcePath + '.pre-build-optimizer.js';
  const outputFilePath = this.resourcePath + '.post-build-optimizer.js';

  const boOutput = buildOptimizer({
    content,
    originalFilePath: this.resourcePath,
    inputFilePath,
    outputFilePath,
    emitSourceMap: options.sourceMap,
    isSideEffectFree: this._module
                      && this._module.factoryMeta
                      && this._module.factoryMeta.sideEffectFree,
  });

  if (boOutput.emitSkipped || boOutput.content === null) {
    // Webpack typings for previousSourceMap are wrong, they are JSON objects and not strings.
    // tslint:disable-next-line:no-any
    this.callback(null, content, previousSourceMap as any);

    return;
  }

  const intermediateSourceMap = boOutput.sourceMap;
  let newContent = boOutput.content;

  let newSourceMap;

  if (options.sourceMap && intermediateSourceMap) {
    // Webpack doesn't need sourceMappingURL since we pass them on explicitely.
    newContent = newContent.replace(/^\/\/# sourceMappingURL=[^\r\n]*/gm, '');

    if (previousSourceMap) {
      // If there's a previous sourcemap, we have to chain them.
      // See https://github.com/mozilla/source-map/issues/216#issuecomment-150839869 for a simple
      // source map chaining example.
      // Use http://sokra.github.io/source-map-visualization/ to validate sourcemaps make sense.

      // Force the previous sourcemap to use the filename we made up for it.
      // In order for source maps to be chained, the consumed source map `file` needs to be in the
      // consumers source map `sources` array.
      previousSourceMap.file = inputFilePath;

      // Chain the sourcemaps.
      const consumer = new SourceMapConsumer(intermediateSourceMap);
      const generator = SourceMapGenerator.fromSourceMap(consumer);
      generator.applySourceMap(new SourceMapConsumer(previousSourceMap));
      newSourceMap = generator.toJSON();
    } else {
      // Otherwise just return our generated sourcemap.
      newSourceMap = intermediateSourceMap;
    }
  }

  // Webpack typings for previousSourceMap are wrong, they are JSON objects and not strings.
  // tslint:disable-next-line:no-any
  this.callback(null, newContent, newSourceMap as any);
}

export function sourceMapTextToGenerator(sourceMapText: string): SourceMapGenerator {
  const sourceMapJson: any = sourceMapText;
  return SourceMapGenerator.fromSourceMap(sourceMapTextToConsumer(sourceMapJson));
}

export function sourceMapConsumerToGenerator(sourceMapConsumer: SourceMapConsumer):
    SourceMapGenerator {
  return SourceMapGenerator.fromSourceMap(sourceMapConsumer);
}