Goodbye `net.ltgt.apt-idea` 👋

apt-idea.gradle

// Put this file in ~/.gradle/init.d/
//
// It will automatically configure Java projects (not Groovy) with for use in IntelliJ IDEA,
// by declaring options.annotationProcessorGeneratedSourcesDirectory as generated sources
// (assumes "Delegate IDE build/run actions to gradle" and "Create separate module per source set";
// only works for 'main' and 'test' source sets).
// The options.annotationProcessorGeneratedSourcesDirectory still needs to be configured in builds
// (see https://github.com/gradle/gradle/issues/4956). This script is thus mainly a workaround for
// the IDEA issue https://youtrack.jetbrains.com/issue/IDEA-182577
//
// In Gradle < 4.6, falls back to applying net.ltgt.apt-idea whenever net.ltgt.apt is applied

import org.gradle.util.GradleVersion;

if (Boolean.getBoolean("idea.active")) {
  def HAS_ANNOTATION_PROCESSOR_PATH = GradleVersion.current() >= GradleVersion.version("4.6")

  allprojects { project ->
    project.apply plugin: 'idea'

    if (HAS_ANNOTATION_PROCESSOR_PATH) {
      project.plugins.withType(JavaPlugin) {
        project.afterEvaluate {
          project.idea.module {
            def mainGeneratedSources = project.tasks["compileJava"].options.annotationProcessorGeneratedSourcesDirectory
            if (mainGeneratedSources) {
              sourceDirs += mainGeneratedSources
              generatedSourceDirs += mainGeneratedSources
            }
            def testGeneratedSources = project.tasks["compileTestJava"].options.annotationProcessorGeneratedSourcesDirectory
            if (testGeneratedSources) {
              testSourceDirs += testGeneratedSources
              generatedSourceDirs += testGeneratedSources
            }
          }
        }
      }
    } else {
      project.plugins.withId("net.ltgt.apt") {
        try {
          project.apply plugin: "net.ltgt.apt-idea"
          project.plugins.withType(JavaPlugin) {
            project.afterEvaluate {
              project.idea.module.apt.addAptDependencies = false
            }
          }
        } catch (UnknownPluginException) {}
      }
    }
  }
}

To configure options.annotationProcessorGeneratedSourcesDirectory in your build, you can use the net.ltgt.apt plugin, or something like the following (assuming Gradle 4.9+ here):

Groovy DSL

sourceSets.all { sourceSet ->
  tasks.named(sourceSet.compileJavaTaskName).configure {
    options.annotationProcessorGeneratedSourcesDirectory = file("$buildDir/generated/source/apt/${sourceSet.name}")
  }
}

Kotlin DSL

sourceSets.all {
  tasks.named<JavaCompile>(compileJavaTaskName).configure {
    options.annotationProcessorGeneratedSourcesDirectory = file("$buildDir/generated/source/apt/${this@all.name}")
  }
}

See https://github.com/tbroyer/gradle-apt-plugin#do-without-the-plugin for more.