runBeforeMainModule is an empty array

[tsyeyuanfeng]

Do you want to request a feature or report a bug?
report a bug

What is the current behavior?
runBeforeMainModule is an empty array. I noticed that runBeforeMainModule config was removed from metro-bundler in this commit Make the runBeforeMainModule config param to RN repo and make it absolute. runBeforeMainModule is passed into Server instance in react-native local-cli.

const options = {
      assetExts: defaultAssetExts.concat(assetExts),
      assetRegistryPath: ASSET_REGISTRY_PATH,
      blacklistRE: config.getBlacklistRE(),
      extraNodeModules: config.extraNodeModules,
      getPolyfills: config.getPolyfills,
      getTransformOptions: config.getTransformOptions,
      globalTransformCache: null,
      hasteImpl: config.hasteImpl,
      maxWorkers: args.maxWorkers,
      platforms: defaultPlatforms.concat(platforms),
      postMinifyProcess: config.postMinifyProcess,
      postProcessModules: config.postProcessModules,
      postProcessBundleSourcemap: config.postProcessBundleSourcemap,
      projectRoots: config.getProjectRoots(),
      providesModuleNodeModules: providesModuleNodeModules,
      resetCache: args.resetCache,
      reporter: new TerminalReporter(terminal),
      runBeforeMainModule: config.runBeforeMainModule,
      sourceExts: defaultSourceExts.concat(sourceExts),
      transformCache: TransformCaching.useTempDir(),
      transformModulePath: transformModulePath,
      useDeltaBundler: false,
      watch: false,
      workerPath: config.getWorkerPath && config.getWorkerPath(),
};

packagerInstance = new Server(options);

However, runBeforeMainModule is not passed into bundle options.
In shared/output/bundle.js module, runBeforeMainModule is not included when packagerClient.buildBundle is called.

// shared/output/bundle.js
function buildBundle(packagerClient: Server, requestOptions: RequestOptions) {
  return packagerClient.buildBundle({
    ...Server.DEFAULT_BUNDLE_OPTIONS,
    ...requestOptions,
    isolateModuleIDs: true,
  });
}

In Server/index module, runBeforeMainModule is also not included when this._bundler.bundle(options) is called.

async buildBundle(options: BundleOptions): Promise<Bundle> {
    const bundle = await this._bundler.bundle(options);
    const modules = bundle.getModules();
    const nonVirtual = modules.filter(m => !m.virtual);
    bundleDeps.set(bundle, {
      files: new Map(
        nonVirtual.map(({sourcePath, meta}) => [
          sourcePath,
          meta != null ? meta.dependencies : [],
        ]),
      ),
      idToIndex: new Map(modules.map(({id}, i) => [id, i])),
      dependencyPairs: new Map(
        nonVirtual
          .filter(({meta}) => meta && meta.dependencyPairs)
          .map(m => [m.sourcePath, m.meta.dependencyPairs]),
      ),
      outdated: new Set(),
    });
    return bundle;
  }

If the current behavior is a bug, please provide the steps to reproduce and a minimal repository on GitHub that we can yarn install and yarn test.

What is the expected behavior?
Shouldn't this._opts.runBeforeMainModule merged into options when this._bundler.bundle(options) is called in buildBundle function of Server module？

Please provide your exact metro-bundler configuration and mention your metro-bundler, node, yarn/npm version and operating system.

[rafeca]

Thanks for reporting!

The commit that you pointed is in fact causing this issue. I'm going to add a fix for it.

In the meantime, as a workaround, can you try to add a require('InitializeCore'); call at the beginning of your bundle entry point?

[miguelocarvajal]

@rafeca Tried to work around the issue but could not figure it out.

What do you mean by bundle entry point exactly?

[miguelocarvajal]

Shortly after posting I saw "react-native run-ios --device" runs:

node /.../node_modules/react-native/local-cli/cli.js bundle --entry-file index.js --platform ios --dev true --reset-cache --bundle-output /.../ios/build/Build/Products/.../main.jsbundle --assets-dest /.../ios/build/...

So bundle entry point is index.js, sorry for that noise.

Adding require('InitializeCore'); did not work around this issue even though I did see a change in the generated main.jsbundle file.

[rafeca]

Adding require('InitializeCore'); did not work around this issue even though I did see a change in the generated main.jsbundle file.

Did you add it before any other require in that file? What error message are you getting?

[miguelocarvajal]

Yes, added it before any other require in the file.

Error message I am getting is:

"ReferenceError: Can't find variable: process"

[petejkim]

require('InitializeCore') doesn't appear to work

[rafeca]

oh, just realized that if you're using import syntax, you'll need to also import InitializeCore (import Foo from 'InitializeCore';), since imports are hoisted before the require statements. Is this the case?

[miguelocarvajal]

That was the case. That resolved it! Thanks so much!