Fix #194: let Gradle check up-to-date-ness of buildConfig decorations

plugin/building/build.gradle.kts

@@ -23,6 +23,7 @@ dependencies {
 
 	testImplementation(projects.test.internal)
 	testImplementation(testFixtures(projects.plugin.base))
+	testImplementation(testFixtures(projects.plugin.versioning))
 	// AndroidInstallRunnerTaskTest calls production code directly, so need com.android.xml.AndroidXPathFactory.
 	testImplementation(libs.android.tools.common)
 }

plugin/building/src/main/kotlin/net/twisterrob/gradle/android/tasks/CalculateBuildTimeTask.kt

@@ -6,45 +6,44 @@ import net.twisterrob.gradle.common.AGPVersions
 import org.gradle.api.DefaultTask
 import org.gradle.api.Project
 import org.gradle.api.file.RegularFileProperty
+import org.gradle.api.provider.Property
 import org.gradle.api.tasks.Input
 import org.gradle.api.tasks.OutputFile
 import org.gradle.api.tasks.TaskAction
 import org.gradle.api.tasks.TaskProvider
-import org.gradle.api.tasks.UntrackedTask
 import java.time.Instant
 import java.time.OffsetDateTime
 import java.time.format.DateTimeFormatter
 import java.time.temporal.ChronoUnit
 
-@UntrackedTask(because = "Input of this task is the current time.")
-open class CalculateBuildTimeTask : DefaultTask() {
+abstract class CalculateBuildTimeTask : DefaultTask() {
 
 	/**
 	 * Default implementation returns a one-day precise time
 	 * to minimize `compile*JavaWithJavac` rebuilds due to a single number change in BuildConfig.java.
 	 *
 	 * It can be overridden like this:
-	 * `tasks.calculateBuildConfigBuildTime.configure { getBuildTime = { System.currentTimeMillis() }}`
+	 * `tasks.calculateBuildConfigBuildTime.configure { buildTime.set(System.currentTimeMillis()) }`
 	 *
 	 * @returns a long representing the UTC time of the build.
 	 */
-	@Input
-	var getBuildTime: () -> Long =
-		{ OffsetDateTime.now().truncatedTo(ChronoUnit.DAYS).toInstant().toEpochMilli() }
+	@get:Input
+	abstract val buildTime: Property<Long>
 
 	@get:OutputFile
 	val buildTimeFile: RegularFileProperty =
 		intermediateRegularFile("buildConfigDecorations/buildTime.txt")
 
 	init {
 		description = "Calculates the build time for BuildConfig.java."
-		outputs.upToDateWhen { false }
+		// Not using a provider to prevent turning over midnight during build,
+		// each build will have a single calculation.
+		buildTime.convention(OffsetDateTime.now().truncatedTo(ChronoUnit.DAYS).toInstant().toEpochMilli())
 	}
 
 	@TaskAction
 	fun writeBuildTime() {
-		val buildTime = getBuildTime()
-		buildTimeFile.writeText(buildTime.toString())
+		buildTimeFile.writeText(buildTime.get().toString())
 	}
 
 	companion object {

plugin/building/src/main/kotlin/net/twisterrob/gradle/android/tasks/CalculateVCSRevisionInfoTask.kt

@@ -10,26 +10,27 @@ import org.gradle.api.file.RegularFileProperty
 import org.gradle.api.tasks.OutputFile
 import org.gradle.api.tasks.TaskAction
 import org.gradle.api.tasks.TaskProvider
-import org.gradle.api.tasks.UntrackedTask
 import org.gradle.kotlin.dsl.getByType
 
-// https://docs.gradle.org/7.3/release-notes.html#plugin-development-improvements
-@UntrackedTask(because = "Input of this task is .git or .svn folder.")
-open class CalculateVCSRevisionInfoTask : DefaultTask() {
+abstract class CalculateVCSRevisionInfoTask : DefaultTask() {
 
 	@get:OutputFile
-	val revisionFile: RegularFileProperty = intermediateRegularFile("buildConfigDecorations/revision.txt")
+	val revisionFile: RegularFileProperty =
+		intermediateRegularFile("buildConfigDecorations/revision.txt")
 
 	@get:OutputFile
-	val revisionNumberFile: RegularFileProperty = intermediateRegularFile("buildConfigDecorations/revisionNumber.txt")
+	val revisionNumberFile: RegularFileProperty =
+		intermediateRegularFile("buildConfigDecorations/revisionNumber.txt")
 
 	init {
-		outputs.upToDateWhen { false }
+		inputs.files(project.provider { vcs.current.files(project) })
 	}
 
+	private val vcs: VCSPluginExtension
+		get() = project.extensions.getByType()
+
 	@TaskAction
 	fun writeVCS() {
-		val vcs: VCSPluginExtension = project.extensions.getByType()
 		revisionFile.writeText(vcs.current.revision)
 		revisionNumberFile.writeText(vcs.current.revisionNumber.toString())
 	}

plugin/building/src/test/kotlin/net/twisterrob/gradle/android/AndroidBuildPluginIntgTest.kt

@@ -24,6 +24,8 @@ import java.time.ZoneOffset
  * [Delete %TEMP%\robolectric-2 folder](https://github.com/robolectric/robolectric/issues/4567#issuecomment-475740375)
  *
  * @see AndroidBuildPlugin
+ * @see net.twisterrob.gradle.android.tasks.CalculateBuildTimeTask
+ * @see net.twisterrob.gradle.android.tasks.CalculateVCSRevisionInfoTask
  */
 @ExtendWith(GradleRunnerRuleExtension::class)
 class AndroidBuildPluginIntgTest : BaseAndroidIntgTest() {
@@ -416,7 +418,7 @@ class AndroidBuildPluginIntgTest : BaseAndroidIntgTest() {
 				//noinspection UnnecessaryQualifiedReference
 				testLogging.events = org.gradle.api.tasks.testing.logging.TestLogEvent.values().toList().toSet()
 			}
-			tasks.named("calculateBuildConfigBuildTime").configure { getBuildTime = { 1234567890 } }
+			tasks.named("calculateBuildConfigBuildTime").configure { buildTime.set(1234567890L) }
 		""".trimIndent()
 
 		val result = gradle.run(script, "testReleaseUnitTest").build()

plugin/building/src/test/kotlin/net/twisterrob/gradle/android/tasks/CalculateBuildTimeTaskIntgTest.kt

@@ -0,0 +1,49 @@
+package net.twisterrob.gradle.android.tasks
+
+import net.twisterrob.gradle.android.BaseAndroidIntgTest
+import net.twisterrob.gradle.test.GradleRunnerRule
+import net.twisterrob.gradle.test.GradleRunnerRuleExtension
+import net.twisterrob.gradle.test.assertSuccess
+import net.twisterrob.gradle.test.assertUpToDate
+import org.intellij.lang.annotations.Language
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.extension.ExtendWith
+
+/**
+ * @see CalculateBuildTimeTask
+ */
+@ExtendWith(GradleRunnerRuleExtension::class)
+class CalculateBuildTimeTaskIntgTest : BaseAndroidIntgTest() {
+
+	override lateinit var gradle: GradleRunnerRule
+
+	@Test fun `will stay up to date`() {
+		@Language("gradle")
+		val script = """
+			apply plugin: 'net.twisterrob.vcs'
+			tasks.register("calculateBuildConfigBuildTime", ${CalculateBuildTimeTask::class.java.name})
+		""".trimIndent()
+
+		val first = gradle.run(script, "calculateBuildConfigBuildTime").build()
+		first.assertSuccess(":calculateBuildConfigBuildTime")
+
+		val second = gradle.run(null, "calculateBuildConfigBuildTime").build()
+		second.assertUpToDate(":calculateBuildConfigBuildTime")
+	}
+
+	@Test fun `will stay up to date with custom value`() {
+		@Language("gradle")
+		val script = """
+			apply plugin: 'net.twisterrob.vcs'
+			tasks.register("calculateBuildConfigBuildTime", ${CalculateBuildTimeTask::class.java.name}) {
+				buildTime.set(1234L)
+			}
+		""".trimIndent()
+
+		val first = gradle.run(script, "calculateBuildConfigBuildTime").build()
+		first.assertSuccess(":calculateBuildConfigBuildTime")
+
+		val second = gradle.run(null, "calculateBuildConfigBuildTime").build()
+		second.assertUpToDate(":calculateBuildConfigBuildTime")
+	}
+}

plugin/building/src/test/kotlin/net/twisterrob/gradle/android/tasks/CalculateVCSRevisionInfoTaskIntgTest.kt

@@ -0,0 +1,158 @@
+package net.twisterrob.gradle.android.tasks
+
+import net.twisterrob.gradle.android.BaseAndroidIntgTest
+import net.twisterrob.gradle.test.GradleRunnerRule
+import net.twisterrob.gradle.test.GradleRunnerRuleExtension
+import net.twisterrob.gradle.test.assertSuccess
+import net.twisterrob.gradle.test.assertUpToDate
+import net.twisterrob.gradle.test.root
+import net.twisterrob.gradle.vcs.createTestFileToCommit
+import net.twisterrob.gradle.vcs.doCheckout
+import net.twisterrob.gradle.vcs.doCommitSingleFile
+import net.twisterrob.gradle.vcs.doCreateRepository
+import net.twisterrob.gradle.vcs.git
+import net.twisterrob.gradle.vcs.svn
+import org.intellij.lang.annotations.Language
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.extension.ExtendWith
+
+/**
+ * @see CalculateVCSRevisionInfoTask
+ */
+@ExtendWith(GradleRunnerRuleExtension::class)
+class CalculateVCSRevisionInfoTaskIntgTest : BaseAndroidIntgTest() {
+
+	override lateinit var gradle: GradleRunnerRule
+
+	@Test fun `will stay up to date when didn't change`() {
+		@Language("gradle")
+		val script = """
+			apply plugin: 'net.twisterrob.vcs'
+			if (project.VCS.current == project.VCS.git || project.VCS.current == project.VCS.svn) {
+				throw new IllegalStateException("Not dummy: " + project.VCS.current)
+			}
+			tasks.register("calculateBuildConfigVCSRevisionInfo", ${CalculateVCSRevisionInfoTask::class.java.name})
+		""".trimIndent()
+
+		val first = gradle.run(script, "calculateBuildConfigVCSRevisionInfo").build()
+		first.assertSuccess(":calculateBuildConfigVCSRevisionInfo")
+
+		val second = gradle.run(null, "calculateBuildConfigVCSRevisionInfo").build()
+		second.assertUpToDate(":calculateBuildConfigVCSRevisionInfo")
+	}
+
+	@Test fun `will stay up to date when git didn't change`() {
+		git(gradle.root) {
+			doCommitSingleFile(gradle.root.createTestFileToCommit(), "First commit")
+			doCommitSingleFile(gradle.root.createTestFileToCommit(), "Second commit")
+		}
+		@Language("gradle")
+		val script = """
+			apply plugin: 'net.twisterrob.vcs'
+			if (project.VCS.current != project.VCS.git) {
+				throw new IllegalStateException("Not git: " + project.VCS.current)
+			}
+			tasks.register("calculateBuildConfigVCSRevisionInfo", ${CalculateVCSRevisionInfoTask::class.java.name})
+		""".trimIndent()
+
+		val first = gradle.run(script, "calculateBuildConfigVCSRevisionInfo").build()
+		first.assertSuccess(":calculateBuildConfigVCSRevisionInfo")
+
+		val second = gradle.run(null, "calculateBuildConfigVCSRevisionInfo").build()
+		second.assertUpToDate(":calculateBuildConfigVCSRevisionInfo")
+	}
+
+	@Test fun `will stay up to date when git sha didn't change`() {
+		git(gradle.root) {
+			val rev = doCommitSingleFile(gradle.root.createTestFileToCommit(), "First commit")
+			doCheckout(rev.id)
+		}
+		@Language("gradle")
+		val script = """
+			apply plugin: 'net.twisterrob.vcs'
+			if (project.VCS.current != project.VCS.git) {
+				throw new IllegalStateException("Not git: " + project.VCS.current)
+			}
+			tasks.register("calculateBuildConfigVCSRevisionInfo", ${CalculateVCSRevisionInfoTask::class.java.name})
+		""".trimIndent()
+
+		val first = gradle.run(script, "calculateBuildConfigVCSRevisionInfo").build()
+		first.assertSuccess(":calculateBuildConfigVCSRevisionInfo")
+
+		val second = gradle.run(null, "calculateBuildConfigVCSRevisionInfo").build()
+		second.assertUpToDate(":calculateBuildConfigVCSRevisionInfo")
+	}
+
+	@Test fun `will not stay up to date when git changed`() {
+		git(gradle.root) {
+			doCommitSingleFile(gradle.root.createTestFileToCommit(), "First commit")
+		}
+		@Language("gradle")
+		val script = """
+			apply plugin: 'net.twisterrob.vcs'
+			if (project.VCS.current != project.VCS.git) {
+				throw new IllegalStateException("Not git: " + project.VCS.current)
+			}
+			tasks.register("calculateBuildConfigVCSRevisionInfo", ${CalculateVCSRevisionInfoTask::class.java.name})
+		""".trimIndent()
+
+		val first = gradle.run(script, "calculateBuildConfigVCSRevisionInfo").build()
+		first.assertSuccess(":calculateBuildConfigVCSRevisionInfo")
+
+		git(gradle.root) {
+			doCommitSingleFile(gradle.root.createTestFileToCommit(), "Second commit")
+		}
+
+		val second = gradle.run(null, "calculateBuildConfigVCSRevisionInfo").withDebug(true).build()
+		second.assertSuccess(":calculateBuildConfigVCSRevisionInfo")
+	}
+
+	@Test fun `will stay up to date when svn didn't change`() {
+		svn {
+			val repoUrl = doCreateRepository(gradle.root.resolve(".repo"))
+			doCheckout(repoUrl, gradle.root)
+			doCommitSingleFile(gradle.root.createTestFileToCommit(), "First commit")
+			doCommitSingleFile(gradle.root.createTestFileToCommit(), "Second commit")
+		}
+		@Language("gradle")
+		val script = """
+			apply plugin: 'net.twisterrob.vcs'
+			if (project.VCS.current != project.VCS.svn) {
+				throw new IllegalStateException("Not svn: " + project.VCS.current)
+			}
+			tasks.register("calculateBuildConfigVCSRevisionInfo", ${CalculateVCSRevisionInfoTask::class.java.name})
+		""".trimIndent()
+
+		val first = gradle.run(script, "calculateBuildConfigVCSRevisionInfo").build()
+		first.assertSuccess(":calculateBuildConfigVCSRevisionInfo")
+
+		val second = gradle.run(null, "calculateBuildConfigVCSRevisionInfo").build()
+		second.assertUpToDate(":calculateBuildConfigVCSRevisionInfo")
+	}
+
+	@Test fun `will not stay up to date when svn changed`() {
+		svn {
+			val repoUrl = doCreateRepository(gradle.root.resolve(".repo"))
+			doCheckout(repoUrl, gradle.root)
+			doCommitSingleFile(gradle.root.createTestFileToCommit(), "First commit")
+		}
+		@Language("gradle")
+		val script = """
+			apply plugin: 'net.twisterrob.vcs'
+			if (project.VCS.current != project.VCS.svn) {
+				throw new IllegalStateException("Not svn: " + project.VCS.current)
+			}
+			tasks.register("calculateBuildConfigVCSRevisionInfo", ${CalculateVCSRevisionInfoTask::class.java.name})
+		""".trimIndent()
+
+		val first = gradle.run(script, "calculateBuildConfigVCSRevisionInfo").build()
+		first.assertSuccess(":calculateBuildConfigVCSRevisionInfo")
+
+		svn {
+			doCommitSingleFile(gradle.root.createTestFileToCommit(), "Second commit")
+		}
+
+		val second = gradle.run(null, "calculateBuildConfigVCSRevisionInfo").build()
+		second.assertSuccess(":calculateBuildConfigVCSRevisionInfo")
+	}
+}

plugin/versioning/build.gradle.kts

@@ -1,6 +1,7 @@
 plugins {
 	kotlin
 	id("java-gradle-plugin")
+	id("java-test-fixtures")
 	id("net.twisterrob.gradle.build.publishing")
 }
 
@@ -31,4 +32,7 @@ dependencies {
 
 	testImplementation(projects.test.internal)
 	testImplementation(testFixtures(projects.plugin.base))
+
+	testFixturesApi(libs.svnkit)
+	testFixturesApi(libs.jgit)
 }

plugin/versioning/src/main/kotlin/net/twisterrob/gradle/vcs/DummyVcsExtension.kt

@@ -1,9 +1,13 @@
 package net.twisterrob.gradle.vcs
 
+import org.gradle.api.Project
+import org.gradle.api.file.FileCollection
+
 internal object DummyVcsExtension : VCSExtension {
 
 	override val isAvailableQuick: Boolean = false
 	override val isAvailable: Boolean = isAvailableQuick
 	override val revision: String = "no VCS"
 	override val revisionNumber: Int = 0
+	override fun files(project: Project): FileCollection = project.files()
 }

plugin/versioning/src/main/kotlin/net/twisterrob/gradle/vcs/GITPlugin.kt

@@ -11,6 +11,7 @@ import org.eclipse.jgit.lib.RepositoryCache
 import org.eclipse.jgit.revwalk.RevWalk
 import org.eclipse.jgit.util.FS
 import org.gradle.api.Project
+import org.gradle.api.file.FileCollection
 import org.gradle.kotlin.dsl.create
 import org.gradle.kotlin.dsl.getByName
 import java.io.File
@@ -76,6 +77,26 @@ open class GITPluginExtension : VCSExtension {
 				return count()
 			}
 		}
+
+	override fun files(project: Project): FileCollection =
+		project.files(
+			".git/HEAD",
+			project.provider {
+				val headRef = project.rootDir.resolve(".git/HEAD")
+				if (headRef.exists() && headRef.isFile && headRef.canRead()) {
+					val headRaw = headRef.readText().trimEnd()
+					if (headRaw.startsWith("ref: ")) {
+						// HEAD contains a ref, resolve it to a file containing the SHA as the input.
+						project.rootDir.resolve(".git").resolve(headRaw.substringAfter("ref: "))
+					} else {
+						// HEAD contains an SHA, that's the input.
+						headRef
+					}
+				} else {
+					error("Cannot find ${headRef}, consider android.twisterrob.decorateBuildConfig = false")
+				}
+			}
+		)
 }
 
 private inline fun <T> inRepo(dir: File, block: Git.() -> T): T {