Make the compatibility metadata variant check more specific (#3103)

3 files changed, 33 insertions, 18 deletions

diff --git a/runners/gradle-plugin/api/gradle-plugin.api b/runners/gradle-plugin/api/gradle-plugin.api
index d7d38d2f..0ec172b7 100644
--- a/runners/gradle-plugin/api/gradle-plugin.api
+++ b/runners/gradle-plugin/api/gradle-plugin.api
@@ -179,7 +179,3 @@ public final class org/jetbrains/dokka/gradle/internal/AbstractDokkaTaskExtensio
 	public static synthetic fun buildJsonConfiguration$default (Lorg/jetbrains/dokka/gradle/AbstractDokkaTask;ZILjava/lang/Object;)Ljava/lang/String;
 }
 
-public final class org/jetbrains/dokka/gradle/kotlin/KotlinClasspathUtilsKt {
-	public static final fun isHMPPEnabled (Lorg/gradle/api/Project;)Z
-}
-
diff --git a/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/kotlin/kotlinClasspathUtils.kt b/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/kotlin/kotlinClasspathUtils.kt
index b534dcc4..1d1d18fc 100644
--- a/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/kotlin/kotlinClasspathUtils.kt
+++ b/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/kotlin/kotlinClasspathUtils.kt
@@ -5,25 +5,12 @@ import org.gradle.api.file.FileCollection
 import org.jetbrains.dokka.gradle.isAndroidTarget
 import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSet
 import org.jetbrains.kotlin.gradle.plugin.mpp.AbstractKotlinNativeCompilation
-import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinCommonCompilation
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
 
-val Project.isHMPPEnabled
-    // [KotlinCommonCompilation.isKlibCompilation] is internal, so we use this
-    get() = (this.findProperty("kotlin.mpp.enableGranularSourceSetsMetadata") as? String)?.toBoolean() ?: false
-
 internal fun Project.classpathOf(sourceSet: KotlinSourceSet): FileCollection {
     val compilations = compilationsOf(sourceSet)
     return if (compilations.isNotEmpty()) {
         compilations
-            /**
-             * If the project has enabled Compatibility Metadata Variant (produces legacy variant),
-             * we don't touch it due to some dependant library
-             * might be published without Compatibility Metadata Variant.
-             * Dokka needs only HMPP variant
-             * Ignore [org.jetbrains.kotlin.gradle.plugin.mpp.KotlinCommonCompilation]  for `commonMain`  sourceSet with name `main`
-             */
-            .filterNot { compilation -> isHMPPEnabled && compilation is KotlinCommonCompilation && compilation.name == "main" }
             .map { compilation -> compilation.compileClasspathOf(project = this) }
             .reduce { acc, fileCollection -> acc + fileCollection }
     } else {
diff --git a/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/kotlin/kotlinCompilationUtils.kt b/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/kotlin/kotlinCompilationUtils.kt
index 1d06e608..ab781432 100644
--- a/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/kotlin/kotlinCompilationUtils.kt
+++ b/runners/gradle-plugin/src/main/kotlin/org/jetbrains/dokka/gradle/kotlin/kotlinCompilationUtils.kt
@@ -6,15 +6,47 @@ import org.jetbrains.kotlin.gradle.dsl.KotlinCommonOptions
 import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformExtension
 import org.jetbrains.kotlin.gradle.dsl.KotlinSingleTargetExtension
 import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSet
+import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinCommonCompilation
 
 internal typealias KotlinCompilation =
         org.jetbrains.kotlin.gradle.plugin.KotlinCompilation<KotlinCommonOptions>
 
 internal fun Project.compilationsOf(sourceSet: KotlinSourceSet): List<KotlinCompilation> {
     //KT-45412 Make sure .kotlinSourceSets and .allKotlinSourceSets include the default source set
-    return allCompilationsOf(sourceSet).filter { compilation ->
+    val compilations = allCompilationsOf(sourceSet).filter { compilation ->
         sourceSet in compilation.kotlinSourceSets || sourceSet == compilation.defaultSourceSet
     }
+
+    val hasAdditionalCommonCompatibilityMetadataVariant = compilations.size >= 2
+            && this.isHmppEnabled()
+            && compilations.any { it is KotlinCommonCompilation && it.compilationName == "main" }
+            && compilations.any { it is KotlinCommonCompilation && it.compilationName == "commonMain" }
+
+    return if (hasAdditionalCommonCompatibilityMetadataVariant) {
+        // If the project has `kotlin.mpp.enableCompatibilityMetadataVariant` set to `true`
+        // and it produces a legacy variant for common, we filter it out because one of the dependencies
+        // might be published without it, and it would lead to the following error:
+        //
+        // > Execution failed for task ':project:dokkaHtmlPartial'.
+        // > Could not resolve all files for configuration ':project:metadataCompileClasspath'.
+        //    > Could not resolve com.example.dependency:0.1.0.
+        //       > The consumer was configured to find a usage of 'kotlin-api' of a library, preferably optimized for
+        //         non-jvm, as well as attribute 'org.jetbrains.kotlin.platform.type' with value 'common'. However we
+        //         cannot choose between the following variants of com.example.dependency:0.1.0:
+        //
+        // This can be reproduced consistently on Ktor of version 2.3.2
+        compilations.filterNot { it is KotlinCommonCompilation && it.compilationName == "main" }
+    } else {
+        compilations
+    }
+}
+
+private fun Project.isHmppEnabled(): Boolean {
+    // [KotlinCommonCompilation.isKlibCompilation] is internal, so we use this property instead.
+    // The property name might seem misleading, but it's set by KGP if HMPP is enabled:
+    // https://github.com/JetBrains/kotlin/blob/1.9.0/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/internal/hierarchicalStructureMigrationHandling.kt#L33
+    return (this.findProperty("kotlin.mpp.enableGranularSourceSetsMetadata") as? String)?.toBoolean()
+        ?: false
 }
 
 internal fun Project.allCompilationsOf(