react-native/ReactAndroid
Vojtech Novak e3d3533bc5 improve NativeModuleRegistryBuilder.java (#16402)
Summary:
I met the error `Native module xyz tried to override xyz for module name xyzModuleName. If this was your intention...` after something went wrong during `react-native link` - one module somehow ended up being included twice in the `getPackages` method, as in:

```java
Override
        protected List<ReactPackage> getPackages() {
            return Arrays.<ReactPackage>asList(
                    new MainReactPackage(),
            new WowPackage(),
            new WowPackage(),
```

Since I have > 20 native modules it took me a little while to find out what the problem was. The improved error message should make the problem clearer to anybody who may encounter it. I did try to refactor the code a little more, by extracting the whole part of:

```java
        String name = moduleHolder.getName();
        if (namesToType.containsKey(name)) {
          Class<? extends NativeModule> existingNativeModule = namesToType.get(name);
          if (!moduleHolder.getCanOverrideExistingModule()) {
            throw new IllegalStateException(getModuleOverridingExceptionMessage(
              type.getSimpleName(),
              existingNativeModule.getSimpleName(),
              name
            ));
          }

          mModules.remove(existingNativeModule);
        }

        namesToType.put(name, type);
        mModules.put(type, moduleHolder);
```

out into a separate method since there were two places where nearly identical code was written.

I have built RN from source and used it in a very simple app with RN vector icons (the package creates a native module as can be seen [here](https://github.com/oblador/react-native-vector-icons/blob/master/android/src/main/java/com/oblador/vectoricons/VectorIconsPackage.java#L19)).

After including the module twice, ie.

```java
        Override
        protected List<ReactPackage> getPackages() {
            return Arrays.<ReactPackage>asList(
                    new MainReactPackage(),
                    new VectorIconsPackage(),
                    new VectorIconsPackage()
            );
        }
```

I get the improved error description, as seen in the screenshot.

<img src="https://user-images.githubusercontent.com/1566403/36340960-3289d9d0-13e7-11e8-8d17-e1651da17841.png" height="500">

[ANDROID] [MINOR] [NativeModuleRegistryBuilder] - Improve error message and refactor putting native modules to module maps
Closes https://github.com/facebook/react-native/pull/16402

Differential Revision: D8421392

Pulled By: hramos

fbshipit-source-id: 719bd37b4681933d35858621b402ae73dd460a5b
2018-06-14 08:25:39 -07:00
..
2016-10-04 10:43:35 -07:00
2018-05-27 15:17:55 -07:00

Building React Native for Android

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