RNGP - findPackageJsonFile should return null if package.json does not exist

[tido64]

Summary

findPackageJsonFile always returns a path even though package.json does not exist. This causes issues in libraries whose repo setups look like:

react-native-webview
├── android
│   └── build.gradle
├── example  <-- Note the lack of `package.json` here
│   └── App.tsx
├── ios
│   └── RNCWebView.xcodeproj
├── macos
│   └── RNCWebView.xcodeproj
├── package.json
└── src

When newArchEnabled=true, running yarn android will fail with the following:

FAILURE: Build failed with an exception.

* What went wrong:
Could not determine the dependencies of task ':app:generateCodegenArtifactsFromSchema'.
> Could not create task ':app:generateCodegenSchemaFromJavaScript'.
   > /~/react-native-webview/example/package.json (No such file or directory)

Changelog

[Android] [Fixed] - findPackageJsonFile should return null if package.json does not exist

Test Plan

git clone https://github.com/react-native-webview/react-native-webview.git
cd react-native-webview
git checkout new-arch-ios
yarn
cd example/android
./gradlew clean assembleDebug

[tido64]

cc @Titozzz

[analysis-bot]

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

Base commit: 56b10a8
Branch: main

[cortinico]

Thanks for doing this @tido64

1. Can you write a test for it here?
   

   react-native/packages/react-native-gradle-plugin/src/test/kotlin/com/facebook/react/utils/PathUtilsTest.kt

   Lines 225 to 250 in 032bed4

   	@Test
   	fun findPackageJsonFile_withFileInParentFolder_picksItUp() {
   	tempFolder.newFile("package.json")
   	val moduleFolder = tempFolder.newFolder("awesome-module")
   	val project = ProjectBuilder.builder().withProjectDir(moduleFolder).build()
   	project.plugins.apply("com.android.library")
   	project.plugins.apply("com.facebook.react")
   	val extension = project.extensions.getByType(ReactExtension::class.java)
   	assertEquals(project.file("../package.json"), findPackageJsonFile(project, extension))
   	}
   	@Test
   	fun findPackageJsonFile_withFileConfiguredInExtension_picksItUp() {
   	val moduleFolder = tempFolder.newFolder("awesome-module")
   	val localFile = File(moduleFolder, "package.json").apply { writeText("{}") }
   	val project = ProjectBuilder.builder().withProjectDir(moduleFolder).build()
   	project.plugins.apply("com.android.library")
   	project.plugins.apply("com.facebook.react")
   	val extension =
   	project.extensions.getByType(ReactExtension::class.java).apply { root.set(moduleFolder) }
   	assertEquals(localFile, findPackageJsonFile(project, extension))
   	}

2. I believe the problem here is that @Titozzz had root misconfigured inside the library. root should be placed to where the root of the package/library so in this folder setup:

react-native-webview <--- root should be here
├── android
│   └── build.gradle
├── example
│   └── App.tsx
├── ios
│   └── RNCWebView.xcodeproj
├── macos
│   └── RNCWebView.xcodeproj
├── package.json
└── src 

Making this function return null is correct, but the build will fail at a later stage as the package.json is not found.

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	7,104,305	-41
android	hermes	armeabi-v7a	6,473,067	-40
android	hermes	x86	7,522,581	-40
android	hermes	x86_64	7,381,008	-37
android	jsc	arm64-v8a	8,971,778	-7
android	jsc	armeabi-v7a	7,703,208	-5
android	jsc	x86	9,034,387	-6
android	jsc	x86_64	9,511,779	+3

Base commit: 56b10a8
Branch: main

[facebook-github-bot]

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

[github-actions]

This pull request was successfully merged by @tido64 in 913ebd2.

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