Function encodeSourceMap

front_end/testing/SourceMapEncoder.ts:39–132

(textMap: string[], sourceRoot?: string)

 * as a source map.
 **/
export function encodeSourceMap(textMap: string[], sourceRoot?: string): SDK.SourceMap.SourceMapV3Object {
  let mappings = '';
  const sources: string[] = [];
  const names: string[] = [];
  let sourcesContent: Array<null|string>|undefined;

  const state = {
    line: -1,
    column: 0,
    srcFile: 0,
    srcLine: 0,
    srcColumn: 0,
    srcName: 0,
  };

  for (const mapping of textMap) {
    let match = mapping.match(/^(\d+):(\d+)(?:\s*=>\s*([^:]+):(\d+):(\d+)(?:@(\S+))?)?$/);
    if (!match) {
      match = mapping.match(/^([^:]+):\s*(.+)$/);
      if (!match) {
        throw new Error(`Cannot parse mapping "${mapping}"`);
      }
      (sourcesContent = sourcesContent ?? [])[getOrAddString(sources, match[1])] = match[2];
      continue;
    }

    const lastState = Object.assign({}, state);
    state.line = Number(match[1]);
    state.column = Number(match[2]);
    const hasSource = match[3] !== undefined;
    const hasName = hasSource && (match[6] !== undefined);
    if (hasSource) {
      state.srcFile = getOrAddString(sources, match[3]);
      state.srcLine = Number(match[4]);
      state.srcColumn = Number(match[5]);
      if (hasName) {
        state.srcName = getOrAddString(names, match[6]);
      }
    }

    if (state.line < lastState.line) {
      throw new Error('Line numbers must be increasing');
    }

    const isNewLine = state.line !== lastState.line;

    if (isNewLine) {
      // Fixup for the first line mapping.
      if (lastState.line === -1) {
        lastState.line = 0;
      }
      // Insert semicolons for all the new lines.
      mappings += ';'.repeat(state.line - lastState.line);
      // Reset the compiled code column counter.
      lastState.column = 0;
    } else {
      mappings += ',';
    }