react-native/ReactAndroid/src/main/java/com/facebook/react/NativeModuleRegistryBuilder.java

// Copyright (c) Facebook, Inc. and its affiliates.

// This source code is licensed under the MIT license found in the
// LICENSE file in the root directory of this source tree.

package com.facebook.react;

import com.facebook.react.bridge.ModuleHolder;
import com.facebook.react.bridge.NativeModuleRegistry;
import com.facebook.react.bridge.ReactApplicationContext;
import com.facebook.react.config.ReactFeatureFlags;
import java.util.HashMap;
import java.util.Map;

/** Helper class to build NativeModuleRegistry. */
public class NativeModuleRegistryBuilder {

  private final ReactApplicationContext mReactApplicationContext;
  private final ReactInstanceManager mReactInstanceManager;

  private final Map<String, ModuleHolder> mModules = new HashMap<>();

  public NativeModuleRegistryBuilder(
      ReactApplicationContext reactApplicationContext, ReactInstanceManager reactInstanceManager) {
    mReactApplicationContext = reactApplicationContext;
    mReactInstanceManager = reactInstanceManager;
  }

  public void processPackage(ReactPackage reactPackage) {
    // We use an iterable instead of an iterator here to ensure thread safety, and that this list
    // cannot be modified
    Iterable<ModuleHolder> moduleHolders;
    if (reactPackage instanceof LazyReactPackage) {
      moduleHolders =
          ((LazyReactPackage) reactPackage).getNativeModuleIterator(mReactApplicationContext);
    } else if (reactPackage instanceof TurboReactPackage) {
      moduleHolders =
          ((TurboReactPackage) reactPackage).getNativeModuleIterator(mReactApplicationContext);
    } else {
      moduleHolders =
          ReactPackageHelper.getNativeModuleIterator(
              reactPackage, mReactApplicationContext, mReactInstanceManager);
    }

    for (ModuleHolder moduleHolder : moduleHolders) {
      String name = moduleHolder.getName();
      if (mModules.containsKey(name)) {
        ModuleHolder existingNativeModule = mModules.get(name);
        if (!moduleHolder.getCanOverrideExistingModule()) {
          throw new IllegalStateException(
              "Native module "
                  + name
                  + " tried to override "
                  + existingNativeModule.getClassName()
                  + ". Check the getPackages() method in MainApplication.java, it might be that module is being created twice. If this was your intention, set canOverrideExistingModule=true");
        }
        mModules.remove(existingNativeModule);
      }
      if (ReactFeatureFlags.useTurboModules && moduleHolder.isTurboModule()) {
        // If this module is a TurboModule, and if TurboModules are enabled, don't add this module

        // This condition is after checking for overrides, since if there is already a module,
        // and we want to override it with a turbo module, we would need to remove the modules thats
        // already in the list, and then NOT add the new module, since that will be directly exposed

        // Note that is someone uses {@link NativeModuleRegistry#registerModules}, we will NOT check
        // for TurboModules - assuming that people wanted to explicitly register native modules
        // there
        continue;
      }
      mModules.put(name, moduleHolder);
    }
  }

  public NativeModuleRegistry build() {
    return new NativeModuleRegistry(mReactApplicationContext, mModules);
  }
}