Detect and warn if project adds an explicit dependency on Kotlin Coro…

…utines library

CHANGELOG.md

@@ -6,6 +6,7 @@
 - Configure all tasks that extend task classes instead of just those created by the plugin 
 - Make JbrResolver prefer Gradle javaToolchains by `JetBrains s.r.o`, if available. Only otherwise start fetching and running a new one.
 - Support for Kotlin Coroutines debugging
+- Detect and warn if project adds an explicit dependency on Kotlin Coroutines library
 
 ### Changed
 - Disabled caching for `BuildPluginTask`

src/main/kotlin/org/jetbrains/intellij/IntelliJPlugin.kt

@@ -803,6 +803,13 @@ abstract class IntelliJPlugin : Plugin<Project> {
                 it.targetCompatibility
             })
             pluginVerifierDownloadDir.convention(downloadDirProvider)
+            kotlinxCoroutinesLibraryPresent.convention(project.provider {
+                listOf(IMPLEMENTATION_CONFIGURATION_NAME, COMPILE_ONLY_CONFIGURATION_NAME).any { configurationName ->
+                    project.configurations.getByName(configurationName).dependencies.any {
+                        it.group == "org.jetbrains.kotlinx" && it.name.startsWith("kotlinx-coroutines")
+                    }
+                }
+            })
 
             kotlinPluginAvailable.convention(project.provider {
                 project.pluginManager.hasPlugin(KOTLIN_GRADLE_PLUGIN_ID)

src/main/kotlin/org/jetbrains/intellij/tasks/VerifyPluginConfigurationTask.kt

@@ -128,6 +128,12 @@ abstract class VerifyPluginConfigurationTask @Inject constructor(
     @get:Internal
     abstract val pluginVerifierDownloadDir: Property<String>
 
+    /**
+     * This variable represents whether the Kotlin Coroutines library is added explicitly to the project dependencies.
+     */
+    @get:Internal
+    abstract val kotlinxCoroutinesLibraryPresent: Property<Boolean>
+
     private val context = logCategory()
 
     init {
@@ -190,6 +196,9 @@ abstract class VerifyPluginConfigurationTask @Inject constructor(
             if (kotlinPluginAvailable.get() && kotlinVersion >= Version(1, 8, 20) && kotlinVersion < Version(1, 9) && kotlinIncrementalUseClasspathSnapshot.orNull == null) {
                 yield("The Kotlin plugin in version $kotlinVersion used with the Gradle IntelliJ Plugin leads to the 'java.lang.OutOfMemoryError: Java heap space' exception, see: https://jb.gg/intellij-platform-kotlin-oom")
             }
+            if (kotlinxCoroutinesLibraryPresent.get()) {
+                yield("The Kotlin Coroutines library should not be added explicitly to the project as it is already provided with the IntelliJ Platform.")
+            }
         }.joinToString("\n") { "- $it" }.takeIf(String::isNotEmpty)?.let {
             warn(
                 context,

src/test/kotlin/org/jetbrains/intellij/tasks/VerifyPluginConfigurationTaskSpec.kt

@@ -210,6 +210,25 @@ class VerifyPluginConfigurationTaskSpec : IntelliJPluginSpecBase() {
         }
     }
 
+    @Test
+    fun `report kotlinx-coroutines dependency`() {
+        buildFile.groovy(
+            """
+            dependencies {
+                implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core-jvm:1.7.1")
+            }
+            """.trimIndent()
+        )
+
+        build(VERIFY_PLUGIN_CONFIGURATION_TASK_NAME).let {
+            assertContains(HEADER, it.output)
+            assertContains(
+                "- The Kotlin Coroutines library should not be added explicitly to the project as it is already provided with the IntelliJ Platform.",
+                it.output
+            )
+        }
+    }
+
     companion object {
         const val HEADER = "The following plugin configuration issues were found"
     }