Fix: Codegen template error in RCTThirdPartyFabricComponentsProvider

[gispada]

Summary

When GenerateRCTThirdPartyFabricComponentsProviderCpp.js generates RCTThirdPartyFabricComponentsProvider.mm an edge case happens in the following situation:

• The same library exports multiple modules with one component each (i.e. one component per file);
• The first component is excluded for iOS via the excludedPlatforms property in codegenNativeComponent.

A "loose" comma appears in the generated template, breaking the code.

Class<RCTComponentViewProtocol> RCTThirdPartyFabricComponentsProvider(const char *name) {
  static std::unordered_map<std::string, Class (*)(void)> sFabricComponentsClassMap = {
, // <-- the offending comma
    {"NativeComponent2", NativeComponent2Cls}, // rnmylibrary
  };
}

At some point, GenerateRCTThirdPartyFabricComponentsProviderCpp.js does not properly filter out empty arrays resulting from excluded components. This does not seem to be a problem when the excluded component is not the first being processed, as the comma gets added at the end of the previous line, after the comment with the name of the library.

Changelog

[iOS] [Fixed] - Fix error in the Codegen template for ThirdPartyFabricComponentsProvider

Test Plan

This is the schema that leads to the bug. Notice that the first component was excluded for iOS.

{
  "modules": {
    "ComponentFile1": {
      "type": "Component",
      "components": {
        "NativeComponent1": {
          "excludedPlatforms": ["iOS"]
          "extendsProps": [
            {
              "type": "ReactNativeBuiltInType",
              "knownTypeName": "ReactNativeCoreViewProps"
            }
          ],
          "events": [],
          "props": [],
          "commands": []
        }
      }
    },
    "ComponentFile2": {
      "type": "Component",
      "components": {
        "NativeComponent2": {
          "extendsProps": [
            {
              "type": "ReactNativeBuiltInType",
              "knownTypeName": "ReactNativeCoreViewProps"
            }
          ],
          "events": [],
          "props": [],
          "commands": []
        }
      }
    }
  }

GenerateRCTThirdPartyFabricComponentsProviderCpp.js should generate a template without the comma in the wrong position (before NativeComponent2).

I also added an additional test case to cover this problem. All the other tests passed.

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	7,694,714	-3,959
android	hermes	armeabi-v7a	7,098,254	-4,007
android	hermes	x86	7,997,448	-3,971
android	hermes	x86_64	7,969,961	-4,027
android	jsc	arm64-v8a	9,565,274	-4,136
android	jsc	armeabi-v7a	8,332,257	-4,164
android	jsc	x86	9,505,691	-4,145
android	jsc	x86_64	10,097,336	-4,180

Base commit: bcb5808
Branch: main

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
ios	-	universal	n/a	--

Base commit: c27501b
Branch: main

[facebook-github-bot]

@cipolleschi has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[react-native-bot]

This pull request was successfully merged by Gianluca Spada in 2f6b212.

^{When will my fix make it into a release? | Upcoming Releases}