Add unit tests for BuildCodegenCLITask

Summary:
This Diff is adding some tests for BuildCodegenCLITask.
Plus I found a bug in how we pass the input/output relative to `codegenDir`
so I'm fixing the properties to use `by lazy{}`.

Moreover the `output` was not correctly annotated with `OutputDirectories`,
fixing it here.

Changelog:
[Internal] [Changed] - Add unit tests for BuildCodegenCLITask

Reviewed By: ShikaSD

Differential Revision: D31109599

fbshipit-source-id: bec75b216e8cef18072179c89c3223ee2bad74e3

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

@@ -27,10 +27,12 @@ abstract class BuildCodegenCLITask : Exec() {
   @get:Internal abstract val bashWindowsHome: Property<String>
 
   @get:InputFiles
-  val input: FileCollection =
-      codegenDir.files("scripts", "src", "package.json", ".babelrc", ".prettierrc")
+  val input: FileCollection by lazy {
+    codegenDir.get().files("scripts", "src", "package.json", ".babelrc", ".prettierrc")
+  }
 
-  @get:OutputFiles val output: FileCollection = codegenDir.files("lib", "node_modules")
+  @get:OutputDirectories
+  val output: FileCollection by lazy { codegenDir.get().files("lib", "node_modules") }
 
   init {
     // We need this condition as we want a single instance of BuildCodegenCLITask to execute

packages/react-native-gradle-plugin/src/test/kotlin/com/facebook/react/tasks/BuildCodegenCLITaskTest.kt

@@ -0,0 +1,75 @@
+/*
+ * 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.tasks
+
+import com.facebook.react.tests.createTestTask
+import java.io.File
+import org.gradle.api.tasks.*
+import org.junit.Assert.*
+import org.junit.Rule
+import org.junit.Test
+import org.junit.rules.TemporaryFolder
+
+class BuildCodegenCLITaskTest {
+
+  @get:Rule val tempFolder = TemporaryFolder()
+
+  @Test
+  fun buildCodegenCli_input_isSetCorrectly() {
+    val task = createTestTask<BuildCodegenCLITask> { it.codegenDir.set(tempFolder.root) }
+
+    assertTrue(task.input.contains(File(tempFolder.root, "scripts")))
+    assertTrue(task.input.contains(File(tempFolder.root, "src")))
+    assertTrue(task.input.contains(File(tempFolder.root, "package.json")))
+    assertTrue(task.input.contains(File(tempFolder.root, ".babelrc")))
+    assertTrue(task.input.contains(File(tempFolder.root, ".prettierrc")))
+  }
+
+  @Test
+  fun buildCodegenCli_output_isSetCorrectly() {
+    val task = createTestTask<BuildCodegenCLITask> { it.codegenDir.set(tempFolder.root) }
+
+    assertTrue(task.output.contains(File(tempFolder.root, "lib")))
+    assertTrue(task.output.contains(File(tempFolder.root, "node_modules")))
+  }
+
+  @Test
+  fun buildCodegenCli_bashWindowsHome_isSetCorrectly() {
+    val bashPath = tempFolder.newFile("bash").absolutePath
+    val task = createTestTask<BuildCodegenCLITask> { it.bashWindowsHome.set(bashPath) }
+
+    assertEquals(bashPath, task.bashWindowsHome.get())
+  }
+
+  @Test
+  fun buildCodegenCli_onlyIf_withMissingDirectory_isSatisfied() {
+    File(tempFolder.root, "lib/cli/").apply { mkdirs() }
+    val task = createTestTask<BuildCodegenCLITask> { it.codegenDir.set(tempFolder.root) }
+
+    assertTrue(task.onlyIf.isSatisfiedBy(task))
+  }
+
+  @Test
+  fun buildCodegenCli_onlyIf_withEmptyDirectory_isSatisfied() {
+    File(tempFolder.root, "lib/cli/").apply { mkdirs() }
+    val task = createTestTask<BuildCodegenCLITask> { it.codegenDir.set(tempFolder.root) }
+
+    assertTrue(task.onlyIf.isSatisfiedBy(task))
+  }
+
+  @Test
+  fun buildCodegenCli_onlyIf_withExistingDirtyDirectory_isNotSatisfied() {
+    File(tempFolder.root, "lib/cli/a-file").apply {
+      parentFile.mkdirs()
+      writeText("¯\\_(ツ)_/¯")
+    }
+    val task = createTestTask<BuildCodegenCLITask> { it.codegenDir.set(tempFolder.root) }
+
+    assertFalse(task.onlyIf.isSatisfiedBy(task))
+  }
+}

packages/react-native-gradle-plugin/src/test/kotlin/com/facebook/react/tests/TaskTestUtils.kt

@@ -0,0 +1,25 @@
+/*
+ * 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.tests
+
+import org.gradle.api.Project
+import org.gradle.api.Task
+import org.gradle.testfixtures.ProjectBuilder
+
+internal fun createProject(): Project {
+  with(ProjectBuilder.builder().build()) {
+    plugins.apply("com.facebook.react")
+    return this
+  }
+}
+
+internal inline fun <reified T : Task> createTestTask(
+    project: Project = createProject(),
+    taskName: String = T::class.java.simpleName,
+    crossinline block: (T) -> Unit = {}
+): T = project.tasks.register(taskName, T::class.java) { block(it) }.get()