feat(build): replace homebrew ktfmt formatter with Spotless

Spotless has fixed their Gradle Configuration Cache woes in the past
couple months which gets rid of my primary complaint.

.github/renovate.json5

@@ -68,6 +68,16 @@
       "datasourceTemplate": "maven",
       "depNameTemplate": "androidx.compose.compiler:compiler",
       "registryUrlTemplate": "https://maven.google.com",
+    },
+    {
+      "fileMatch": [
+        "build-logic/src/main/kotlin/app/passwordstore/gradle/SpotlessPlugin.kt"
+      ],
+      "matchStrings": [
+        "KTFMT_VERSION = \"(?<currentValue>.*)\""
+      ],
+      "datasourceTemplate": "maven",
+      "depNameTemplate": "com.facebook:ktfmt"
     }
   ]
 }

.github/workflows/pull_request.yml

@@ -20,7 +20,7 @@ jobs:
 
       - name: Check codestyle
         shell: bash
-        run: ./gradlew ktfmtCheck
+        run: ./gradlew spotlessCheck
 
       - name: Upload Kotlin build report
         if: "${{ always() }}"

build-logic/build.gradle.kts

@@ -41,10 +41,6 @@ gradlePlugin {
       id = "com.github.android-password-store.kotlin-jvm-library"
       implementationClass = "app.passwordstore.gradle.KotlinJVMLibrary"
     }
-    register("ktfmt") {
-      id = "com.github.android-password-store.ktfmt"
-      implementationClass = "app.passwordstore.gradle.KtfmtPlugin"
-    }
     register("published-android-library") {
       id = "com.github.android-password-store.published-android-library"
       implementationClass = "app.passwordstore.gradle.PublishedAndroidLibraryPlugin"
@@ -61,6 +57,10 @@ gradlePlugin {
       id = "com.github.android-password-store.sentry"
       implementationClass = "app.passwordstore.gradle.SentryPlugin"
     }
+    register("spotless") {
+      id = "com.github.android-password-store.spotless"
+      implementationClass = "app.passwordstore.gradle.SpotlessPlugin"
+    }
     register("versioning") {
       id = "com.github.android-password-store.versioning-plugin"
       implementationClass = "app.passwordstore.gradle.versioning.VersioningPlugin"
@@ -79,7 +79,6 @@ dependencies {
   implementation(libs.build.download)
   implementation(libs.build.javapoet)
   implementation(libs.build.kotlin)
-  implementation(libs.build.ktfmt)
   implementation(libs.build.mavenpublish)
   implementation(libs.build.metalava)
   implementation(libs.build.moshi)
@@ -88,6 +87,7 @@ dependencies {
   implementation(libs.build.r8)
   implementation(libs.build.semver)
   implementation(libs.build.sentry)
+  implementation(libs.build.spotless)
   implementation(libs.build.vcu)
   implementation(libs.kotlinx.coroutines.core)
 

build-logic/src/main/kotlin/app/passwordstore/gradle/KtfmtPlugin.kt

@@ -1,37 +0,0 @@
-package app.passwordstore.gradle
-
-import app.passwordstore.gradle.ktfmt.KtfmtCheckTask
-import app.passwordstore.gradle.ktfmt.KtfmtFormatTask
-import com.facebook.ktfmt.format.FormattingOptions
-import java.util.concurrent.Callable
-import org.gradle.api.Plugin
-import org.gradle.api.Project
-import org.gradle.kotlin.dsl.register
-
-class KtfmtPlugin : Plugin<Project> {
-
-  override fun apply(target: Project) {
-    val input = Callable {
-      target.layout.projectDirectory.asFileTree.filter { file ->
-        file.extension == "kt" || file.extension == "kts" && !file.canonicalPath.contains("build/")
-      }
-    }
-    target.tasks.register<KtfmtFormatTask>("ktfmtFormat") { source(input) }
-    target.tasks.register<KtfmtCheckTask>("ktfmtCheck") {
-      source(input)
-      projectDirectory.set(target.layout.projectDirectory)
-    }
-  }
-
-  companion object {
-    val DEFAULT_FORMATTING_OPTIONS =
-      FormattingOptions(
-        maxWidth = FormattingOptions.DEFAULT_MAX_WIDTH,
-        blockIndent = 2,
-        continuationIndent = 2,
-        removeUnusedImports = true,
-        debuggingPrintOpsAfterFormatting = false,
-        manageTrailingCommas = true,
-      )
-  }
-}

build-logic/src/main/kotlin/app/passwordstore/gradle/SpotlessPlugin.kt

@@ -0,0 +1,44 @@
+/*
+ * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package app.passwordstore.gradle
+
+import com.diffplug.gradle.spotless.SpotlessExtension
+import com.diffplug.gradle.spotless.SpotlessPlugin
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.kotlin.dsl.apply
+import org.gradle.kotlin.dsl.getByType
+
+@Suppress("Unused")
+class SpotlessPlugin : Plugin<Project> {
+
+  override fun apply(project: Project) {
+    project.pluginManager.apply(SpotlessPlugin::class)
+    project.extensions.getByType<SpotlessExtension>().run {
+      kotlin {
+        ktfmt(KTFMT_VERSION).googleStyle()
+        target("**/*.kt")
+        targetExclude("**/build/")
+      }
+      kotlinGradle {
+        ktfmt(KTFMT_VERSION).googleStyle()
+        target("**/*.kts")
+        targetExclude("**/build/")
+      }
+      format("xml") {
+        target("**/*.xml")
+        targetExclude("**/build/", ".idea/")
+        trimTrailingWhitespace()
+        indentWithSpaces()
+        endWithNewline()
+      }
+    }
+  }
+
+  private companion object {
+    private const val KTFMT_VERSION = "0.51"
+  }
+}

build-logic/src/main/kotlin/app/passwordstore/gradle/ktfmt/KtfmtCheckTask.kt

@@ -1,63 +0,0 @@
-package app.passwordstore.gradle.ktfmt
-
-import app.passwordstore.gradle.KtfmtPlugin
-import com.facebook.ktfmt.format.Formatter
-import java.io.File
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.ExperimentalCoroutinesApi
-import kotlinx.coroutines.async
-import kotlinx.coroutines.awaitAll
-import kotlinx.coroutines.coroutineScope
-import kotlinx.coroutines.runBlocking
-import org.gradle.api.GradleException
-import org.gradle.api.file.DirectoryProperty
-import org.gradle.api.file.FileCollection
-import org.gradle.api.tasks.IgnoreEmptyDirectories
-import org.gradle.api.tasks.InputFiles
-import org.gradle.api.tasks.Internal
-import org.gradle.api.tasks.PathSensitive
-import org.gradle.api.tasks.PathSensitivity
-import org.gradle.api.tasks.SourceTask
-import org.gradle.api.tasks.TaskAction
-
-@OptIn(ExperimentalCoroutinesApi::class)
-abstract class KtfmtCheckTask : SourceTask() {
-
-  @get:PathSensitive(PathSensitivity.RELATIVE)
-  @get:InputFiles
-  @get:IgnoreEmptyDirectories
-  protected val inputFiles: FileCollection
-    get() = super.getSource()
-
-  @get:Internal abstract val projectDirectory: DirectoryProperty
-
-  @TaskAction
-  fun execute() {
-    runBlocking(Dispatchers.IO.limitedParallelism(PARALLEL_TASK_LIMIT)) {
-      coroutineScope {
-        val results = inputFiles.map { async { checkFile(it) } }.awaitAll()
-        if (results.any { (notFormatted, _) -> notFormatted }) {
-          val prettyDiff =
-            results
-              .map { (_, diffs) -> diffs }
-              .flatten()
-              .joinToString(separator = "\n") { diff -> diff.toString() }
-          throw GradleException("[ktfmt] Found unformatted files\n${prettyDiff}")
-        }
-      }
-    }
-  }
-
-  private fun checkFile(input: File): Pair<Boolean, List<KtfmtDiffEntry>> {
-    val originCode = input.readText()
-    val formattedCode = Formatter.format(KtfmtPlugin.DEFAULT_FORMATTING_OPTIONS, originCode)
-    val pathNormalizer = { file: File -> file.toRelativeString(projectDirectory.asFile.get()) }
-    return (originCode != formattedCode) to
-      KtfmtDiffer.computeDiff(input, formattedCode, pathNormalizer)
-  }
-
-  companion object {
-
-    private const val PARALLEL_TASK_LIMIT = 4
-  }
-}

build-logic/src/main/kotlin/app/passwordstore/gradle/ktfmt/KtfmtDiffEntry.kt

@@ -1,8 +0,0 @@
-package app.passwordstore.gradle.ktfmt
-
-data class KtfmtDiffEntry(val input: String, val lineNumber: Int, val message: String) {
-
-  override fun toString(): String {
-    return "$input:$lineNumber - $message"
-  }
-}

build-logic/src/main/kotlin/app/passwordstore/gradle/ktfmt/KtfmtDiffer.kt

@@ -1,28 +0,0 @@
-package app.passwordstore.gradle.ktfmt
-
-import com.github.difflib.DiffUtils
-import com.github.difflib.patch.ChangeDelta
-import com.github.difflib.patch.DeleteDelta
-import com.github.difflib.patch.InsertDelta
-import java.io.File
-
-object KtfmtDiffer {
-  fun computeDiff(
-    inputFile: File,
-    formattedCode: String,
-    pathNormalizer: (File) -> String,
-  ): List<KtfmtDiffEntry> {
-    val originCode = inputFile.readText()
-    return DiffUtils.diff(originCode, formattedCode, null).deltas.map {
-      val line = it.source.position + 1
-      val message: String =
-        when (it) {
-          is ChangeDelta -> "Line changed: ${it.source.lines.first()}"
-          is DeleteDelta -> "Line deleted"
-          is InsertDelta -> "Line added"
-          else -> ""
-        }
-      KtfmtDiffEntry(pathNormalizer(inputFile), line, message)
-    }
-  }
-}

build-logic/src/main/kotlin/app/passwordstore/gradle/ktfmt/KtfmtFormatTask.kt

@@ -1,46 +0,0 @@
-package app.passwordstore.gradle.ktfmt
-
-import javax.inject.Inject
-import org.gradle.api.GradleException
-import org.gradle.api.file.ProjectLayout
-import org.gradle.api.tasks.SourceTask
-import org.gradle.api.tasks.TaskAction
-import org.gradle.internal.exceptions.MultiCauseException
-import org.gradle.workers.WorkerExecutor
-import org.jetbrains.kotlin.utils.addToStdlib.ifNotEmpty
-
-abstract class KtfmtFormatTask
-@Inject
-constructor(private val workerExecutor: WorkerExecutor, private val projectLayout: ProjectLayout) :
-  SourceTask() {
-
-  @TaskAction
-  fun execute() {
-    val result =
-      with(workerExecutor.noIsolation()) {
-        submit(KtfmtWorkerAction::class.java) {
-          name.set("ktfmt-worker")
-          files.from(source)
-          projectDirectory.set(projectLayout.projectDirectory.asFile)
-        }
-        runCatching { await() }
-      }
-
-    result.exceptionOrNull()?.workErrorCauses<Exception>()?.ifNotEmpty {
-      forEach { logger.error(it.message, it.cause) }
-      throw GradleException("error formatting sources for $name")
-    }
-  }
-
-  private inline fun <reified T : Throwable> Throwable.workErrorCauses(): List<Throwable> {
-    return when (this) {
-        is MultiCauseException -> this.causes.map { it.cause }
-        else -> listOf(this.cause)
-      }
-      .filter {
-        // class instance comparison doesn't work due to different classloaders
-        it?.javaClass?.canonicalName == T::class.java.canonicalName
-      }
-      .filterNotNull()
-  }
-}

build-logic/src/main/kotlin/app/passwordstore/gradle/ktfmt/KtfmtWorkerAction.kt

@@ -1,38 +0,0 @@
-package app.passwordstore.gradle.ktfmt
-
-import app.passwordstore.gradle.KtfmtPlugin
-import com.facebook.ktfmt.format.Formatter
-import java.io.File
-import org.gradle.api.logging.LogLevel
-import org.gradle.api.logging.Logger
-import org.gradle.api.logging.Logging
-import org.gradle.internal.logging.slf4j.DefaultContextAwareTaskLogger
-import org.gradle.workers.WorkAction
-
-abstract class KtfmtWorkerAction : WorkAction<KtfmtWorkerParameters> {
-  private val logger: Logger =
-    DefaultContextAwareTaskLogger(Logging.getLogger(KtfmtFormatTask::class.java))
-  private val files: List<File> = parameters.files.toList()
-  private val projectDirectory: File = parameters.projectDirectory.asFile.get()
-  private val name: String = parameters.name.get()
-
-  override fun execute() {
-    try {
-      files.forEach { file ->
-        val sourceText = file.readText()
-        val relativePath = file.toRelativeString(projectDirectory)
-
-        logger.log(LogLevel.DEBUG, "$name checking format: $relativePath")
-
-        val formattedText = Formatter.format(KtfmtPlugin.DEFAULT_FORMATTING_OPTIONS, sourceText)
-
-        if (!formattedText.contentEquals(sourceText)) {
-          logger.log(LogLevel.QUIET, "${file.toRelativeString(projectDirectory)}: Format fixed")
-          file.writeText(formattedText)
-        }
-      }
-    } catch (t: Throwable) {
-      throw Exception("format worker execution error", t)
-    }
-  }
-}

build-logic/src/main/kotlin/app/passwordstore/gradle/ktfmt/KtfmtWorkerParameters.kt

@@ -1,12 +0,0 @@
-package app.passwordstore.gradle.ktfmt
-
-import org.gradle.api.file.ConfigurableFileCollection
-import org.gradle.api.file.RegularFileProperty
-import org.gradle.api.provider.Property
-import org.gradle.workers.WorkParameters
-
-interface KtfmtWorkerParameters : WorkParameters {
-  val name: Property<String>
-  val files: ConfigurableFileCollection
-  val projectDirectory: RegularFileProperty
-}

build.gradle.kts

@@ -5,6 +5,6 @@
 plugins {
   id("com.github.android-password-store.git-hooks")
   id("com.github.android-password-store.kotlin-common")
-  id("com.github.android-password-store.ktfmt")
+  id("com.github.android-password-store.spotless")
   id("com.github.android-password-store.versions")
 }

gradle/libs.versions.toml

@@ -39,7 +39,6 @@ build-diffutils = "io.github.java-diff-utils:java-diff-utils:4.12"
 build-download = "de.undercouch:gradle-download-task:5.6.0"
 build-javapoet = "com.squareup:javapoet:1.13.0"
 build-kotlin = { module = "org.jetbrains.kotlin:kotlin-gradle-plugin", version.ref = "kotlin" }
-build-ktfmt = "com.facebook:ktfmt:0.51"
 build-mavenpublish = "com.vanniktech:gradle-maven-publish-plugin:0.29.0"
 build-metalava = "me.tylerbwong.gradle.metalava:plugin:0.3.5"
 build-moshi = { module = "com.squareup.moshi:moshi", version.ref = "moshi" }
@@ -48,6 +47,7 @@ build-okhttp = "com.squareup.okhttp3:okhttp:5.0.0-alpha.14"
 build-r8 = "com.android.tools:r8:8.4.6-dev"
 build-semver = "com.github.zafarkhaja:java-semver:0.10.2"
 build-sentry = "io.sentry.android.gradle:io.sentry.android.gradle.gradle.plugin:4.11.0"
+build-spotless = "com.diffplug.spotless:spotless-plugin-gradle:6.25.0"
 build-vcu = "nl.littlerobots.version-catalog-update:nl.littlerobots.version-catalog-update.gradle.plugin:0.8.4"
 compose-bom = "androidx.compose:compose-bom:2024.06.00"
 compose-foundation-core = { module = "androidx.compose.foundation:foundation" }

scripts/pre-push-hook.sh

@@ -13,6 +13,6 @@ while read -r local_ref local_oid remote_ref remote_oid; do
   _=$remote_ref
   _=$remote_oid
   if [ "${local_oid}" != "${ZERO}" ]; then
-    CI=true "${GRADLE_EXEC}" metalavaCheckCompatibilityRelease lint ktfmtCheck test -PslimTests
+    CI=true "${GRADLE_EXEC}" metalavaCheckCompatibilityRelease lint spotlessCheck test -PslimTests
   fi
 done