Add non-isolated mode

.gitignore

@@ -1,3 +1,27 @@
-.idea
+.kotlin
+.fleet
 .gradle
-build
+
+# Build outputs
+build
+
+# Idea
+**/.idea/*
+!**/.idea/codeStyles
+!**/.idea/icon.png
+!**/.idea/runConfigurations
+!**/.idea/scopes
+!**/.idea/dictionaries
+*.iml
+
+# Place where the Android SDK path is set
+local.properties
+
+# XCode
+xcuserdata
+project.xcworkspace
+
+# Mac OS Finder
+.DS_Store
+Thumbs.db
+

README.md

@@ -2,45 +2,34 @@
 
 Gratatouille is an opinionated framework to build Gradle plugins. Write pure Kotlin functions and the Gratatouille KSP processor generates tasks, workers, and wiring code for you.
 
-Gratatouille enforces a clear separation between your plugin logic (**implementation**) and your plugin wiring (**gradle-plugin**) making your plugin immune to [classloader issues](https://github.com/square/kotlinpoet/issues/1730#issuecomment-1819118527) 🛡️ 
+When used in classloader isolation mode, Gratatouille enforces a clear separation between your plugin logic (**implementation**) and your plugin wiring (**api**) making your plugin immune to [classloader issues](https://github.com/square/kotlinpoet/issues/1730#issuecomment-1819118527) 🛡️ 
 
 **Key Features**:
 
 * [Pure functions](#pure-functions)
 * [Kotlinx serialization support](#built-in-kotlinxserialization-support)
 * [Comprehensive input/output types](#supported-input-and-output-types)
 * [Non overlapping task outputs](#non-overlapping-task-outputs-by-default)
-* [Classloader isolation](#classloader-isolation-by-default)
 * [Build cache](#build-cache-by-default)
 * [Documentation](#easy-documentation)
 * [Parallel execution](#parallel-task-execution-by-default)
 * [Compile-time task wiring](#compile-time-task-wiring)
+* [Classloader isolation](#classloader-isolation-optional) (optional)
 
 Check out the [sample-plugin](sample-plugin) and [sample-app](sample-app).
 
 ## Quick Start
 
-### Step 1/2: `com.gradleup.gratatouille.implementation` 
-
-Create an `implementation` module for your plugin implementation and apply the `com.gradleup.gratatouille.implementation` plugin:
+Apply the `com.gradleup.gratatouille` plugin:
 
 ```kotlin
-// implementation/build.gradle.kts
 plugins {
-    id("com.gradleup.gratatouille.implementation").version("0.0.1")
-}
-
-dependencies {
-    // Add the gratatouille annotations
-    implementation("com.gradleup.gratatouille:gratatouille-core:0.0.1")
-    // Add other dependencies
-    implementation("com.squareup:kotlinpoet:1.14.2")
-    implementation("org.ow2.asm:asm-commons:9.6")
-    // do **not** add gradleApi() here
+    id("java-gradle-plugin")
+    id("com.gradleup.gratatouille").version("0.0.2")
 }
 ```
 
-Write your task action as a pure top-level Kotlin function annotated with `@GTaskAction`:
+Define your task action using `@GTaskAction`:
 
 ```kotlin
 @GTaskAction
@@ -65,35 +54,113 @@ Gratatouille automatically maps function parameters to Gradle inputs and the ret
 
 Gratatouille generates entry points, tasks, workers and Gradle wiring code that you can then use to cook your plugin.
 
-### Step 2/2 `com.gradleup.gratatouille.plugin` 
+<details>
+<summary>Generated code</summary>
 
-To use the generated code in your plugin, create a `gradle-plugin` module next to your `implementation` module. 
+```kotlin
+internal fun Project.registerPrepareIngredientsTask(
+  taskName: String = "prepareIngredients",
+  taskDescription: String? = null,
+  taskGroup: String? = null,
+  persons: Provider<Int>,
+): TaskProvider<PrepareIngredientsTask> {
+  val configuration = this@registerPrepareIngredientsTask.configurations.detachedConfiguration()
+  configuration.dependencies.add(dependencies.create("sample-plugin:implementation:0.0.1"))
+  return tasks.register(taskName,PrepareIngredientsTask::class.java) {
+    it.description = taskDescription
+    it.group = taskGroup
+    it.classpath.from(configuration)
+    // infrastructure
+    // inputs
+    it.persons.set(persons)
+    // outputs
+    it.outputFile.set(this@registerPrepareIngredientsTask.layout.buildDirectory.file("gtask/${taskName}/outputFile"))
+  }
+}
 
-> [!IMPORTANT]
-> By using two different modules, Gratatouille ensures that Gradle classes do not leak in your plugin implementation and vice-versa.
+@CacheableTask
+internal abstract class PrepareIngredientsTask : DefaultTask() {
+  @get:InputFiles
+  @get:PathSensitive(PathSensitivity.RELATIVE)
+  public abstract val classpath: ConfigurableFileCollection
+
+  @get:Input
+  public abstract val persons: Property<Int>
+
+  @get:OutputFile
+  public abstract val outputFile: RegularFileProperty
+
+  @Inject
+  public abstract fun getWorkerExecutor(): WorkerExecutor
+
+  private fun <T> T.isolate(): T {
+    @kotlin.Suppress("UNCHECKED_CAST")
+    when (this) {
+        is Set<*> -> {
+            return this.map { it.isolate() }.toSet() as T
+        }
+
+        is List<*> -> {
+            return this.map { it.isolate() } as T
+        }
+
+        is Map<*, *> -> {
+            return entries.map { it.key.isolate() to it.value.isolate() }.toMap() as T
+        }
+
+        else -> {
+            return this
+        }
+    }
+  }
+
+  @TaskAction
+  public fun taskAction() {
+    getWorkerExecutor().noIsolation().submit(PrepareIngredientsWorkAction::class.java) {
+      it.classpath = classpath.files.isolate()
+      it.persons = persons.get().isolate()
+      it.outputFile = outputFile.asFile.get().isolate()
+    }
+  }
+}
 
-Apply the `com.gradleup.gratatouille.plugin` plugin in your `gradle-plugin` module:
+private interface PrepareIngredientsWorkParameters : WorkParameters {
+  public var classpath: Set<File>
 
-```kotlin
-// gradle-plugin/build.gradle.kts
-plugins {
-    id("java-gradle-plugin")
-    id("com.gradleup.gratatouille.plugin").version("0.0.1")
+  public var persons: Int
+
+  public var outputFile: File
 }
 
-dependencies {
-    // Add your implementation module to the "gratatouille" configuration.
-    // This does not add `:implementation` to your plugin classpath.
-    // Instead, the generated code uses reflection and a separate classloader to run
-    // your implementation
-    gratatouille(project(":implementation"))
+private abstract class PrepareIngredientsWorkAction : WorkAction<PrepareIngredientsWorkParameters> {
+  override fun execute() {
+    with(parameters) {
+      URLClassLoader(
+        classpath.map { it.toURI().toURL() }.toTypedArray(),
+        ClassLoader.getPlatformClassLoader()
+      ).loadClass("recipes.PrepareIngredientsEntryPoint")
+      .declaredMethods.single()
+      .invoke(
+        null,
+        persons,
+        outputFile,
+      )
+    }
+  }
 }
 
-// Create your plugin as usual, see https://docs.gradle.org/current/userguide/java_gradle_plugin.html 
-gradlePlugin {
-    // ... 
+public class PrepareIngredientsEntryPoint {
+  public companion object {
+    @JvmStatic
+    public fun run(persons: Int, outputFile: File) {
+      prepareIngredients(
+        persons = persons,
+      ).encodeJsonTo(outputFile)
+    }
+  }
 }
 ```
+</details> 
 
 In your plugin code, use `Project.register${TaskAction}Task()` to register the task:
 
@@ -115,6 +182,8 @@ override fun apply(project: Project) {
 }
 ```
 
+No need to implement `DefaultTask`, no risk of forgetting `@Cacheable`, etc... Gratatouille provides good defaults making it easier to write plugins.
+
 ## Features
 
 ### Pure functions
@@ -185,12 +254,6 @@ project.registerCookTask(
 )
 ```
 
-### Classloader isolation by default
-
-Gratatouille creates a separate classloader for each task and calls your pure functions using reflection. 
-
-This means your plugin can depend on popular dependencies such as the Kotlin stdlib, KotlinPoet or ASM without risking conflicts with other plugins or the Gradle classpath itself. 
-
 ### Build cache by default
 
 `@CacheableTask` is added by default. All input files use `PathSensitivity.RELATIVE` making your tasks relocatable.
@@ -227,3 +290,89 @@ Finally, Gratatouille encourages exposing extensions to users instead of task cl
 
 When a task has a high number of inputs, it can become hard to track which ones have been wired and which ones haven't. By using a central registration point, Gratatouille enforces at build time that all inputs/outputs have been properly wired.
 
+## Classloader isolation (optional)
+
+Gradle uses [multiple classloaders](https://dev.to/autonomousapps/build-compile-run-a-crash-course-in-classpaths-f4g), and it's notoriously really hard to understand where a given class is loaded from.
+
+Especially, `buildSrc`/`build-logic` dependencies [leak in the main classpath](https://github.com/gradle/gradle/issues/4741) and override any dependencies from other plugin without conflict resolution. There are multiple workarounds such as declaring all plugins in `buildSrc` or in the top level `build.gradle[.kts]` file but the situation is confusing to Gradle newcomers and hard to debug.
+
+To guard against those issues, Gratatouille provides a "classloader isolation" mode where your task actions use a separate classloader.
+
+This means your plugin can depend on popular dependencies such as the Kotlin stdlib, KotlinPoet or ASM without risking conflicts with other plugins or the Gradle classpath itself.
+
+For classloader isolation to work, your plugin needs 2 modules:
+* The **implementation** module is where the task actions are defined and the work is done. This module can add dependencies. 
+* The **api** module contains the glue code and Gradle API that calls the **implementation** module through reflection. This module must not add dependencies.
+
+### Step 1/2: `com.gradleup.gratatouille.implementation`
+
+Create an `implementation` module for your plugin implementation and apply the `com.gradleup.gratatouille.implementation` plugin:
+
+```kotlin
+// implementation/build.gradle.kts
+plugins {
+    id("com.gradleup.gratatouille.implementation").version("0.0.1")
+}
+
+dependencies {
+    // Add other dependencies
+    implementation("com.squareup:kotlinpoet:1.14.2")
+    implementation("org.ow2.asm:asm-commons:9.6")
+    // do **not** add gradleApi() here
+}
+```
+
+Write your task action as a pure top-level Kotlin function annotated with `@GTaskAction`:
+
+```kotlin
+@GTaskAction
+internal fun prepareIngredients(persons: Int): Ingredients {
+    return Ingredients(
+        tomatoes = (persons * 0.75).roundToInt(),
+        zucchinis = (persons * 0.3).roundToInt(),
+        eggplants = (persons * 0.3).roundToInt(),
+    )
+}
+
+// kotlinx.serialization is supported out of the box
+@Serializable
+internal data class Ingredients(
+    val tomatoes: Int,
+    val zucchinis: Int,
+    val eggplants: Int,
+)
+```
+
+When using this mode, the plugin wiring code is generated as resources that are included by the `com.gradleup.gratatouille.api` plugin. 
+
+### Step 2/2 `com.gradleup.gratatouille.plugin`
+
+To use the generated code in your plugin, create an `api` module next to your `implementation` module.
+
+> [!IMPORTANT]
+> By using two different modules, Gratatouille ensures that Gradle classes do not leak in your plugin implementation and vice-versa.
+
+Apply the `com.gradleup.gratatouille.api` plugin in your `api` module:
+
+```kotlin
+// gradle-plugin/build.gradle.kts
+plugins {
+    id("java-gradle-plugin")
+    id("com.gradleup.gratatouille.api").version("0.0.1")
+}
+
+dependencies {
+    // Add your implementation module to the "gratatouille" configuration.
+    // This does not add `:implementation` to your plugin classpath.
+    // Instead, the generated code uses reflection and a separate classloader to run
+    // your implementation
+    gratatouille(project(":implementation"))
+}
+
+// Create your plugin as usual, see https://docs.gradle.org/current/userguide/java_gradle_plugin.html 
+gradlePlugin {
+    // ... 
+}
+```
+
+In your plugin code, use `Project.register${TaskAction}Task()` to register the task

build-logic/build.gradle.kts

@@ -1,5 +1,8 @@
+import com.gradleup.librarian.gradle.configureJavaCompatibility
+
 plugins {
     `embedded-kotlin`
+    alias(libs.plugins.librarian).apply(false)
 }
 
 dependencies {
@@ -13,3 +16,9 @@ dependencies {
 }
 
 group = "build-logic"
+
+/**
+ * Ideally would use Runtime.version().feature() but the current Gradle still ships with Kotlin 1.9
+ * that doesn't know about Java 22 🤷‍♂️
+ */
+configureJavaCompatibility(17)

build-logic/gradle/wrapper

@@ -0,0 +1 @@
+../../gradle/wrapper