Function combineSourceMaps

local-cli/bundle/output/unbundle/util.js:52–113

({
  moduleGroups,
  modules,
  withCustomOffsets,
}: CombineSourceMapsOptions)

};

function combineSourceMaps({
  moduleGroups,
  modules,
  withCustomOffsets,
}: CombineSourceMapsOptions): IndexMap {
  const offsets = [];
  const sections = [];
  const sourceMap: IndexMap = withCustomOffsets
    ? {sections, version: 3, x_facebook_offsets: offsets}
    : {sections, version: 3};

  let line = 0;
  modules.forEach(moduleTransport => {
    const {code, id, name} = moduleTransport;
    let column = 0;
    let hasOffset = false;
    let group;
    let groupLines = 0;
    let {map} = moduleTransport;

    if (withCustomOffsets) {
      if (moduleGroups && moduleGroups.modulesInGroups.has(id)) {
        // this is a module appended to another module
        return;
      }


      group = moduleGroups && moduleGroups.groups.get(id);
      if (group && moduleGroups) {
        const {modulesById} = moduleGroups;
        const otherModules: Array<ModuleTransportLike> =
          Array.from(group || [])
            .map(moduleId => modulesById.get(moduleId))
            .filter(Boolean); // needed to appease flow
        otherModules.forEach(m => {
          groupLines += countLines(m.code);
        });
        map = combineSourceMaps({
          modules: [moduleTransport].concat(otherModules),
        });
      }

      hasOffset = id != null;
      column = wrapperEnd(code);
    }

    invariant(
      !Array.isArray(map),
      'Random Access Bundle source maps cannot be built from raw mappings',
    );
    sections.push(Section(line, column, map || lineToLineSourceMap(code, name)));
    if (hasOffset) {
      offsets[id] = line;
      for (const moduleId of group || []) {
        offsets[moduleId] = line;
      }
    }
    line += countLines(code) + groupLines;