Introduce findPackageJsonFile to address issue with GenerateCodegenAr…

…tifactsTaskTest (#34321)

Summary:
While doing some testing with cipolleschi on React Native 0.70.0 we realized that custom Java Package is not properly propagated when invoking codegen for external libraries.

This PR fixes it.

## Changelog

[Internal] - Introduce findPackageJsonFile to address issue with GenerateCodegenArtifactsTaskTest

Pull Request resolved: #34321

Test Plan: Added JUnit tests + Tested locally with cipolleschi

Reviewed By: cipolleschi

Differential Revision: D38314770

Pulled By: cortinico

fbshipit-source-id: ec2de1ba59ffc8fb0644f422521ced642b38d2c7

packages/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/ReactPlugin.kt

@@ -15,6 +15,7 @@ import com.facebook.react.tasks.BuildCodegenCLITask
 import com.facebook.react.tasks.GenerateCodegenArtifactsTask
 import com.facebook.react.tasks.GenerateCodegenSchemaTask
 import com.facebook.react.utils.JsonUtils
+import com.facebook.react.utils.findPackageJsonFile
 import java.io.File
 import kotlin.system.exitProcess
 import org.gradle.api.Plugin
@@ -93,15 +94,7 @@ class ReactPlugin : Plugin<Project> {
           // We're reading the package.json at configuration time to properly feed
           // the `jsRootDir` @Input property of this task. Therefore, the
           // parsePackageJson should be invoked inside this lambda.
-          // We look for `package.json` in the parent folder of this Gradle module
-          // (generally the case for library projects) or we fallback to looking into the `root`
-          // folder of a React Native project (generally the case for app projects).
-          val packageJson =
-              if (project.file("../package.json").exists()) {
-                project.file("../package.json")
-              } else {
-                extension.root.file("package.json").orNull?.asFile
-              }
+          val packageJson = findPackageJsonFile(project, extension)
           val parsedPackageJson = packageJson?.let { JsonUtils.fromCodegenJson(it) }
 
           val jsSrcsDirInPackageJson = parsedPackageJson?.codegenConfig?.jsSrcsDir
@@ -122,7 +115,7 @@ class ReactPlugin : Plugin<Project> {
           it.nodeExecutableAndArgs.set(extension.nodeExecutableAndArgs)
           it.codegenDir.set(extension.codegenDir)
           it.generatedSrcDir.set(generatedSrcDir)
-          it.packageJsonFile.set(extension.root.file("package.json"))
+          it.packageJsonFile.set(findPackageJsonFile(project, extension))
           it.codegenJavaPackageName.set(extension.codegenJavaPackageName)
           it.libraryName.set(extension.libraryName)
         }

packages/react-native-gradle-plugin/src/main/kotlin/com/facebook/react/utils/PathUtils.kt

@@ -11,6 +11,7 @@ package com.facebook.react.utils
 
 import com.facebook.react.ReactExtension
 import java.io.File
+import org.gradle.api.Project
 
 /**
  * Computes the entry file for React Native. The Algo follows this order:
@@ -190,6 +191,18 @@ internal fun projectPathToLibraryName(projectPath: String): String =
         .joinToString("") { token -> token.replaceFirstChar { it.uppercase() } }
         .plus("Spec")
 
+/**
+ * Function to look for the relevant `package.json`. We first look in the parent folder of this
+ * Gradle module (generally the case for library projects) or we fallback to looking into the `root`
+ * folder of a React Native project (generally the case for app projects).
+ */
+internal fun findPackageJsonFile(project: Project, extension: ReactExtension): File? =
+    if (project.file("../package.json").exists()) {
+      project.file("../package.json")
+    } else {
+      extension.root.file("package.json").orNull?.asFile
+    }
+
 private const val HERMESC_IN_REACT_NATIVE_PATH =
     "node_modules/react-native/sdks/hermesc/%OS-BIN%/hermesc"
 private const val HERMESC_BUILT_FROM_SOURCE_PATH =

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

@@ -7,6 +7,7 @@
 
 package com.facebook.react.utils
 
+import com.facebook.react.ReactExtension
 import com.facebook.react.TestReactExtension
 import com.facebook.react.tests.OS
 import com.facebook.react.tests.OsRule
@@ -242,4 +243,29 @@ class PathUtilsTest {
         File("/home/circleci/hermes/build/bin/hermesc"),
         getBuiltHermescFile(tempFolder.root, "/home/circleci/hermes"))
   }
+
+  @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.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.facebook.react")
+    val extension =
+        project.extensions.getByType(ReactExtension::class.java).apply { root.set(moduleFolder) }
+
+    assertEquals(localFile, findPackageJsonFile(project, extension))
+  }
 }