@datadog/mobile-react-native/lib/module/metro/plugin/metroSerializer.js

A client-side React Native module to interact with Datadog

/*
 * Unless explicitly stated otherwise all files in this repository are licensed under the Apache License Version 2.0.
 * This product includes software developed at Datadog (https://www.datadoghq.com/).
 * Copyright 2016-Present Datadog, Inc.
 *
 * Portions of this code are adapted from Sentry's Metro configuration:
 * https://github.com/getsentry/sentry-react-native/blob/17c0c2e8913030e4826d055284a735efad637312/packages/core/src/js/tools/sentryMetroSerializer.ts
 */
import { DEBUG_ID_PLACEHOLDER, addDebugIdModule, checkIfDebugIdModuleExists, createDebugIdFromBundle, createDebugIdModule, getDebugIdFromBundleSource, injectDebugIdInCode, injectDebugIdInCodeAndSourceMap } from './debugIdHelper';
import { getBaseJSBundleFunction, getBundleToStringFunction, convertSerializerOutput as getMetroBundleWithMap, getSortedModules, getSourceMapStringFunction } from './utils';

/**
 * Creates a Metro serializer that adds a Debug ID module to the bundle.
 * This module injects the Debug ID at runtime, making it globally accessible.
 *
 * @param customSerializer - Optional custom {@link MetroSerializer}. If provided, you are responsible
 * for invoking `options.datadogBundleCallback` within it.
 */
export const createDatadogMetroSerializer = customSerializer => {
  const serializer = customSerializer || createDefaultMetroSerializer();
  return async (entryPoint, preModules, graph, options) => {
    // Skip for hot reload mode
    if (graph.transformOptions.hot) {
      return serializer(entryPoint, preModules, graph, options);
    }

    // Make sure we don't add the Debug ID module twice
    if (checkIfDebugIdModuleExists(preModules)) {
      return serializer(entryPoint, preModules, graph, options);
    }

    // Create a virtual module to inject the Debug ID in a globally accessible property
    const debugIdModule = createDebugIdModule(DEBUG_ID_PLACEHOLDER);

    // Set the datadogBundleCallback in the options, to be used later by the serializer
    options.datadogBundleCallback = createDatadogBundleCallback(debugIdModule);

    // Add the Debug ID virtual module to the pre-modules
    const preModulesWithDebugId = addDebugIdModule(preModules, debugIdModule);

    // Run serializer
    const serializerOutput = serializer(entryPoint, preModulesWithDebugId, graph, options);

    // Get serialized code and sourcemap
    const {
      code,
      map
    } = await getMetroBundleWithMap(serializerOutput);

    // Retrieve the Debug ID, previously injected as a snippet of code in a virtual module by `datadogBundleCallback`.
    const debugId = getDebugIdFromBundleSource(code);
    if (!debugId) {
      throw new Error('[DATADOG METRO PLUGIN] Debug ID was not found in the bundle. Call `options.datadogBundleCallback` if you are using a custom serializer.');
    }

    // Inject the Debug ID as a comment in the bundle, and as a top-level property in the sourcemap.
    const result = injectDebugIdInCodeAndSourceMap(debugId, code, map);
    return result;
  };
};

/**
 * Creates a Metro Bundle Serializer like metro does by default, while also calling the datadogBundleCallback.
 * https://github.com/facebook/metro/blob/a3d021a0d021b5706372059f472715c63019e044/packages/metro/src/Server.js#L272-L307
 */
export const createDefaultMetroSerializer = () => {
  return (entryPoint, preModules, graph, options) => {
    // Creates the default metro bundle
    // https://github.com/facebook/metro/blob/a3d021a0d021b5706372059f472715c63019e044/packages/metro/src/DeltaBundler/Serializers/baseJSBundle.js#L25
    const baseJSBundle = getBaseJSBundleFunction();
    let bundle = baseJSBundle(entryPoint, preModules, graph, options);

    // Modify the bundle through the datadogBundleCallback, if we are not in hot-reload mode
    if (options.datadogBundleCallback && !graph.transformOptions.hot) {
      bundle = options.datadogBundleCallback(bundle);
    }

    // Retrieves the processed code from the bundle
    const bundleToString = getBundleToStringFunction();
    const {
      code
    } = bundleToString(bundle);

    // If we are in hot-reload mode, we skip sourcemaps generation, and only return the code.
    if (graph.transformOptions.hot) {
      return code;
    }

    // Force generation of sourcemaps
    const sourceMapString = getSourceMapStringFunction();
    const map = sourceMapString([...preModules, ...getSortedModules(graph, options)], {
      processModuleFilter: options.processModuleFilter,
      shouldAddToIgnoreList: options.shouldAddToIgnoreList
    });
    return {
      code,
      map
    };
  };
};

/**
 * Creates a callback used to transform the given bundle by injecting the Debug ID snippet.
 * @param debugIdModule - The virtual Debug ID module
 * @returns The bundle callback
 */
export const createDatadogBundleCallback = debugIdModule => {
  return bundle => {
    const debugId = createDebugIdFromBundle(bundle);
    const code = debugIdModule.getSource().toString();
    debugIdModule.setSource(injectDebugIdInCode(code, debugId));
    bundle.pre = injectDebugIdInCode(bundle.pre, debugId);
    return bundle;
  };
};

/**
 * Adds Debug ID module for runtime injection, used for Expo.
 */
export function unstable_beforeAssetSerializationPlugin({
  premodules,
  debugId
}) {
  if (!debugId || checkIfDebugIdModuleExists(premodules)) {
    return premodules;
  }
  return [...addDebugIdModule(premodules, createDebugIdModule(debugId))];
}
//# sourceMappingURL=metroSerializer.js.map