Function attachHMRServer

local-cli/server/util/attachHMRServer.js:40–351

* Attaches a WebSocket based connection to the Packager to expose * Hot Module Replacement updates to the simulator.

({httpServer, path, packagerServer}: HMROptions)

 * Hot Module Replacement updates to the simulator.
 */
function attachHMRServer({httpServer, path, packagerServer}: HMROptions) {
  let client = null;

  function disconnect() {
    client = null;
    packagerServer.setHMRFileChangeListener(null);
  }

  // For the give platform and entry file, returns a promise with:
  //   - The full list of dependencies.
  //   - The shallow dependencies each file on the dependency list has
  //   - Inverse shallow dependencies map
  function getDependencies(platform: string, bundleEntry: string): Promise<{
    dependenciesCache: Array<string>,
    dependenciesModulesCache: {[mixed]: Module},
    shallowDependencies: {[string]: Array<Module>},
    inverseDependenciesCache: mixed,
    resolutionResponse: ResolutionResponse<Module, *>,
  }> {
    return packagerServer.getDependencies({
      dev: true,
      entryFile: bundleEntry,
      hot: true,
      minify: false,
      platform: platform,
      recursive: true,
    }).then(response => {
      /* $FlowFixMe: getModuleId might be null */
      const {getModuleId}: {getModuleId: () => number} = response;

      // for each dependency builds the object:
      // `{path: '/a/b/c.js', deps: ['modA', 'modB', ...]}`
      return Promise.all(response.dependencies.map((dep: Module) => {
        return dep.getName().then(depName => {
          if (dep.isAsset() || dep.isJSON()) {
            return Promise.resolve({path: dep.path, deps: []});
          }
          return packagerServer.getShallowDependencies({
            dev: true,
            entryFile: dep.path,
            hot: true,
            minify: false,
            platform: platform,
            recursive: true,
          }).then(deps => {
            return {
              path: dep.path,
              name: depName,
              deps,
            };
          });
        });
      }))
      .then((deps: Array<{path: string, name?: string, deps: Array<Module>}>) => {
        // list with all the dependencies' filenames the bundle entry has
        const dependenciesCache = response.dependencies.map(dep => dep.path);

        // map from module name to path