How to use metro-config - 10 common examples

const ModuleCache = require("./ModuleCache");

const defaults = require("metro-config/src/defaults/defaults");

const parsePlatformFilePath = require("../../node-haste/lib/parsePlatformFilePath");

const path = require("path");

const _require = require("../../node-haste/DependencyGraph/ModuleResolution"),
  ModuleResolver = _require.ModuleResolver;

const _require2 = require("jest-haste-map"),
  ModuleMap = _require2.ModuleMap;

const platforms = new Set(defaults.platforms);
const GENERIC_PLATFORM = "g";
const PACKAGE_JSON = path.sep + "package.json";
const NULL_MODULE = {
  path: "/",

  getPackage() {},

  isHaste() {
    throw new Error("not implemented");
  },

  getName() {
    throw new Error("not implemented");
  }
}; // This function maps the ModuleGraph data structure to jest-haste-map's ModuleMap

async function restart(): Promise {
      if (restarting) {
        return;
      } else {
        restarting = true;
      }

      if (server) {
        // eslint-disable-next-line no-console
        console.log('Configuration changed. Restarting the server...');
        await promisify(server.close).call(server);
      }

      const config = await loadConfig(argv);

      server = await MetroApi.runServer(config, argv);

      restarting = false;
    }

async function restart(): Promise {
      if (restarting) {
        return;
      } else {
        restarting = true;
      }

      if (server) {
        // eslint-disable-next-line no-console
        console.log('Configuration changed. Restarting the server...');
        await promisify(server.close).call(server);
      }

      const config = await loadConfig(argv);

      server = await MetroApi.runServer(config, argv);

      restarting = false;
    }

}

      if (server) {
        // eslint-disable-next-line no-console
        console.log('Configuration changed. Restarting the server...');
        await promisify(server.close).call(server);
      }

      const config = await loadConfig(argv);

      server = await MetroApi.runServer(config, argv);

      restarting = false;
    }

    const foundConfig = await resolveConfig(argv.config, argv.cwd);

    if (foundConfig) {
      await watchFile(foundConfig.filepath, restart);
    } else {
      await restart();
    }
  }),
});

}

      if (server) {
        // eslint-disable-next-line no-console
        console.log('Configuration changed. Restarting the server...');
        await promisify(server.close).call(server);
      }

      const config = await loadConfig(argv);

      server = await MetroApi.runServer(config, argv);

      restarting = false;
    }

    const foundConfig = await resolveConfig(argv.config, argv.cwd);

    if (foundConfig) {
      await watchFile(foundConfig.filepath, restart);
    } else {
      await restart();
    }
  }),
});

async function configure(flags) {
  const reactNativePath = path.dirname(require.resolve('react-native/package.json'));
  const config = await loadConfig();
  const custom = {
    resolver: {},
    serializer: {},
    transformer: {},
    cacheStores: [
      new FileStore({
        root: flags['cache-location']
      })
    ]
  };

  //
  // We need to create a fake package name that we will point to the root
  // of the users directory so we can resolve their requires and test files
  // without having to rely on `package.json` based resolve due to poor
  // handling of absolute and relative paths.

function mergeConfig(...args) {
    const mergedConfig = metroMergeConfig(...args);

    // We need to remove the invalid `symbolicator` config key if it's present and empty.
    if (
        mergedConfig.symbolicator &&
        Object.values(mergedConfig.symbolicator).length === 0
    ) {
        delete mergedConfig.symbolicator;
    }

    return mergedConfig;
}

// - And point to the correct AssetRegistry, also hidden in the React-Native
  //   module.
  //
  // The `providesModuleNodeModules` and `hasteImplModulePath` are currently
  // not needed to correctly configure metro for Ekke as we're replacing
  // `react-native` with  polyfill, but if we for some reason turn this off,
  // we don't want to research the undocumented codebase of Metro, cli, and
  // React-Native again to figure out how to correctly resolve and bundle
  // React-Native.
  //
  custom.resolver.providesModuleNodeModules = ['react-native'];
  custom.resolver.hasteImplModulePath = path.join(reactNativePath, 'jest/hasteImpl');
  custom.resolver.resolverMainFields = ['react-native', 'browser', 'main'];
  custom.transformer.assetRegistryPath = path.join(reactNativePath, 'Libraries/Image/AssetRegistry');

  const merged = mergeConfig(config, custom);
  debug('metro config', merged);

  return merged;
}

deltaBundler
  ) {
    // Get all the polyfills from the relevant option params (the
    // `getPolyfills()` method and the `polyfillModuleNames` variable).
    const polyfillModuleNames = config.serializer
      .getPolyfills({
        platform: options.platform
      })
      .concat(config.serializer.polyfillModuleNames);

    const transformOptions = _objectSpread({}, options, {
      type: "script"
    });

    const graph = yield deltaBundler.buildGraph(
      [defaults.moduleSystem].concat(_toConsumableArray(polyfillModuleNames)),
      {
        resolve: yield transformHelpers.getResolveDependencyFn(
          bundler,
          options.platform
        ),
        transform: yield transformHelpers.getTransformFn(
          [defaults.moduleSystem].concat(
            _toConsumableArray(polyfillModuleNames)
          ),
          bundler,
          deltaBundler,
          config,
          transformOptions
        ),
        onProgress: null
      }

): Promise<$ReadOnlyArray>> {
  // Get all the polyfills from the relevant option params (the
  // `getPolyfills()` method and the `polyfillModuleNames` variable).
  const polyfillModuleNames = config.serializer
    .getPolyfills({
      platform: options.platform,
    })
    .concat(config.serializer.polyfillModuleNames);

  const transformOptions: TransformInputOptions = {
    ...options,
    type: 'script',
  };

  const graph = await deltaBundler.buildGraph(
    [defaults.moduleSystem, ...polyfillModuleNames],
    {
      resolve: await transformHelpers.getResolveDependencyFn(
        bundler,
        options.platform,
      ),
      transform: await transformHelpers.getTransformFn(
        [defaults.moduleSystem, ...polyfillModuleNames],
        bundler,
        deltaBundler,
        config,
        transformOptions,
      ),
      onProgress: null,
      experimentalImportBundleSupport:
        config.transformer.experimentalImportBundleSupport,
      shallow: false,