Ignore files under buildDir directory by default

https://youtrack.jetbrains.com/issue/KT-45161

README.md

@@ -67,7 +67,7 @@ ktlint {
     ktlintVersion = "1.0.0-SNAPSHOT"
     chunkSize = 50
     baselineFile.set(file("config/ktlint_baseline.xml"))
-    ignoreKspGeneratedSources = true
+    ignoreFilesUnderBuildDir = true
 }
 ```
 
@@ -84,7 +84,7 @@ ktlint {
 
 - `chunkSize` - defines how many files will be processed by a single gradle worker in parallel
 - `baselineFile` - points at location of baseline file containing _known_ offenses that will be ignored during `lintKotlin` task execution
-- `ignoreKspGeneratedSources` - indicates if the plugin should automatically register tasks for KSP generated sources (hence triggering compilation tasks). This is an incubating, rather primitive workaround for the issue reported: https://github.com/google/ksp/issues/1261. 
+- `ignoreFilesUnderBuildDir` - This allows to ignore generated sources. This is a workaround for https://youtrack.jetbrains.com/issue/KT-45161. Setting the value to `false` restores default behavior and will run ktlint against all sources returned by KGP  
 
 ### Customizing Tasks
 

gradle/libs.versions.toml

@@ -11,7 +11,8 @@ maven-commons = "2.15.0"
 
 [libraries]
 agp-gradle = { module = "com.android.tools.build:gradle", version.ref = "google-agp" }
-kotlin-gradle = { module = "org.jetbrains.kotlin:kotlin-gradle-plugin" }
+kotlin-gradle-api = { module = "org.jetbrains.kotlin:kotlin-gradle-plugin-api" }
+kotlin-gradle-impl = { module = "org.jetbrains.kotlin:kotlin-gradle-plugin" }
 ktlint-rule-engine = { module = "com.pinterest.ktlint:ktlint-rule-engine", version.ref = "maven-ktlint" }
 ktlint-cli-ruleset-core = { module = "com.pinterest.ktlint:ktlint-cli-ruleset-core", version.ref = "maven-ktlint" }
 ktlint-cli-reporter-core = { module = "com.pinterest.ktlint:ktlint-cli-reporter-core", version.ref = "maven-ktlint" }

ktlint-gradle-plugin/build.gradle

@@ -26,7 +26,7 @@ jacoco {
 }
 
 dependencies {
-    compileOnly(libs.kotlin.gradle)
+    compileOnly(libs.kotlin.gradle.api)
     compileOnly(libs.agp.gradle)
     compileOnly(libs.ktlint.rule.engine)
     compileOnly(libs.ktlint.cli.ruleset.core)
@@ -39,7 +39,7 @@ dependencies {
     testImplementation(libs.commons.io)
     testImplementation(libs.assertj.core)
 
-    testRuntimeDependencies(libs.kotlin.gradle)
+    testRuntimeDependencies(libs.kotlin.gradle.impl)
     testRuntimeDependencies(libs.agp.gradle)
     testRuntimeDependencies(libs.google.ksp.gradle)
 }
@@ -66,8 +66,8 @@ tasks.named("processResources") {
 
 tasks.withType(KotlinCompile).configureEach {
     kotlinOptions {
-        apiVersion = "1.4"
-        languageVersion = "1.4"
+        apiVersion = "1.8"
+        languageVersion = "1.8"
     }
 }
 tasks.withType(Test).configureEach {

ktlint-gradle-plugin/src/main/kotlin/io/github/usefulness/KtlintGradleExtension.kt

@@ -37,5 +37,9 @@ public open class KtlintGradleExtension internal constructor(
     public val baselineFile: RegularFileProperty = objectFactory.fileProperty()
 
     @Incubating
-    public val ignoreKspGeneratedSources: Property<Boolean> = objectFactory.property(default = true)
+    public val ignoreFilesUnderBuildDir: Property<Boolean> = objectFactory.property(default = true)
+
+    @Deprecated(message = "Will be removed in the next version", replaceWith = ReplaceWith(expression = "ignoreFilesUnderBuildDir"))
+    @Incubating
+    public val ignoreKspGeneratedSources: Property<Boolean> = ignoreFilesUnderBuildDir
 }

ktlint-gradle-plugin/src/main/kotlin/io/github/usefulness/KtlintGradlePlugin.kt

@@ -47,7 +47,7 @@ public class KtlintGradlePlugin : Plugin<Project> {
 
                 sourceResolver.applyToAll(this, pluginExtension) { id, resolvedSources ->
                     val checkWorker = tasks.register(
-                        "lintKotlin${id.capitalize()}",
+                        "lintKotlin${id.replaceFirstChar(Char::titlecase)}",
                         LintTask::class.java,
                     ) { task ->
                         task.source(resolvedSources)
@@ -67,7 +67,7 @@ public class KtlintGradlePlugin : Plugin<Project> {
                     lintKotlin.configure { it.dependsOn(checkWorker) }
 
                     val formatWorker = tasks.register(
-                        "formatKotlin${id.capitalize()}",
+                        "formatKotlin${id.replaceFirstChar(Char::titlecase)}",
                         FormatTask::class.java,
                     ) { task ->
                         task.source(resolvedSources)

ktlint-gradle-plugin/src/main/kotlin/io/github/usefulness/SourceSetApplier.kt

@@ -1,10 +1,8 @@
 package io.github.usefulness
 
 import org.gradle.api.Project
-import org.gradle.api.file.FileTree
-import org.gradle.api.provider.Provider
 
-internal typealias SourceSetAction = (String, Provider<FileTree>) -> Unit
+internal typealias SourceSetAction = (String, Any) -> Unit
 
 internal interface SourceSetApplier {
     fun applyToAll(project: Project, extension: KtlintGradleExtension, action: SourceSetAction)

ktlint-gradle-plugin/src/main/kotlin/io/github/usefulness/pluginapplier/AndroidSourceSetApplier.kt

@@ -17,12 +17,12 @@ internal object AndroidSourceSetApplier : SourceSetApplier {
         android.finalizeDsl { commonExtension ->
             commonExtension.sourceSets.configureEach { sourceSet ->
                 val id = sourceSet.name.id
-                action(id, project.provider { getKotlinFiles(project, sourceSet) })
+                action(id, getKotlinFiles(project, sourceSet))
             }
         }
     }
 
-    private fun getKotlinFiles(project: Project, sourceSet: AndroidSourceSet): FileTree? {
+    private fun getKotlinFiles(project: Project, sourceSet: AndroidSourceSet): FileTree {
         val javaSources = sourceSet.java.srcDirs
         val kotlinSources = sourceSet.kotlin.srcDirs
 

ktlint-gradle-plugin/src/main/kotlin/io/github/usefulness/pluginapplier/KotlinSourceSetApplier.kt

@@ -5,15 +5,26 @@ import io.github.usefulness.SourceSetAction
 import io.github.usefulness.SourceSetApplier
 import io.github.usefulness.id
 import org.gradle.api.Project
-import org.jetbrains.kotlin.gradle.dsl.KotlinProjectExtension
+import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSetContainer
+import java.io.File
 
 internal object KotlinSourceSetApplier : SourceSetApplier {
 
     override fun applyToAll(project: Project, extension: KtlintGradleExtension, action: SourceSetAction) {
-        project.extensions.getByType(KotlinProjectExtension::class.java).sourceSets.configureEach { sourceSet ->
-            if (!sourceSet.name.startsWith("generatedByKsp") || !extension.ignoreKspGeneratedSources.get()) {
-                action(sourceSet.kotlin.name.id, project.provider { sourceSet.kotlin })
+        project.extensions.getByType(KotlinSourceSetContainer::class.java).sourceSets.configureEach { sourceSet ->
+            val directories = project.provider {
+                if (extension.ignoreFilesUnderBuildDir.get()) {
+                    sourceSet.kotlin.srcDirTrees.mapNotNull { dirTree ->
+                        dirTree.dir.takeUnless { it.isUnder(project.layout.buildDirectory.asFile.get()) }
+                    }
+                } else {
+                    sourceSet.kotlin.sourceDirectories
+                }
             }
+
+            action(sourceSet.kotlin.name.id, directories)
         }
     }
+
+    private fun File.isUnder(rootDirectory: File) = canonicalPath.startsWith(rootDirectory.canonicalPath)
 }

ktlint-gradle-plugin/src/test/kotlin/io/github/usefulness/functional/ThirdPartyPlugins.kt

@@ -5,12 +5,10 @@ import io.github.usefulness.functional.utils.kotlinClass
 import io.github.usefulness.functional.utils.resolve
 import io.github.usefulness.functional.utils.settingsFile
 import org.assertj.core.api.Assertions.assertThat
-import org.junit.jupiter.api.Disabled
 import org.junit.jupiter.api.Test
 
 class ThirdPartyPlugins : WithGradleTest.Android() {
 
-    @Disabled("This doesn't work with Kotlin 1.9.20 :/ https://github.com/google/ksp/pull/1558")
     @Test
     fun kspKotlin() {
         testProjectDir.apply {
@@ -32,7 +30,9 @@ class ThirdPartyPlugins : WithGradleTest.Android() {
                     repositories.mavenCentral()
                     
                     dependencies {
+                        implementation "com.google.dagger:dagger:2.48.1"
                         ksp "com.google.dagger:dagger-compiler:2.48.1"
+
                     }
                     
                     kotlin {
@@ -53,7 +53,24 @@ class ThirdPartyPlugins : WithGradleTest.Android() {
             resolve("src/main/kotlin/KotlinClass.kt") {
                 writeText(kotlinClass("KotlinClass"))
             }
+            resolve("src/test/kotlin/KotlinTestClass.kt") {
+                writeText(kotlinClass("KotlinTestClass"))
+            }
+            resolve("src/main/kotlin/FooModule.kt") {
+                writeText(
+                    // language=kotlin
+                    """
+                        @dagger.Module
+                        object FooModule {
+                            @dagger.Provides
+                            fun foo(): String = ""
+                        }
+                        
+                    """.trimIndent(),
+                )
+            }
         }
+        build("assemble") // generate files under `build` directory
 
         val result = build("lintKotlin")
 
@@ -79,9 +96,9 @@ class ThirdPartyPlugins : WithGradleTest.Android() {
 
         assertThat(onlyMain.tasks.map { it.path }).containsAll(
             listOf(
+                ":kspKotlin",
                 ":compileKotlin",
                 ":compileJava",
-                ":lintKotlinGeneratedByKspTestKotlin",
                 ":lintKotlinTest",
                 ":lintKotlinMain",
                 ":lintKotlin",
@@ -116,7 +133,7 @@ class ThirdPartyPlugins : WithGradleTest.Android() {
                     repositories.mavenCentral()
                     
                     dependencies {
-                        ksp "com.google.dagger:dagger-compiler:2.48"
+                        ksp "com.google.dagger:dagger-compiler:2.48.1"
                     }
                     
                     """.trimIndent(),