Monkey patch EmbeddedKotlinPlugin to disable 'Unsupported Kotlin plugin version' warning (kotest#4301)

Workaround for gradle/gradle#13020

Gradle _always_ logs an annoying warning: Unsupported Kotlin plugin
version. The warning is always logged, no matter what, and it doesn't
ever seem to represent an actual problem. So, this code downloads the
original EmbeddedKotlinPlugin and disables the warning. Because Gradle's
classloader is hierarchical, the original will be replaced.

---------

Co-authored-by: Sam <[email protected]>

Author: aSemy

buildSrc/build.gradle.kts

@@ -1,3 +1,10 @@
+@file:Suppress("UnstableApiUsage")
+
+import org.gradle.api.attributes.DocsType.DOCS_TYPE_ATTRIBUTE
+import org.gradle.api.attributes.DocsType.SOURCES
+import org.gradle.kotlin.dsl.support.expectedKotlinDslPluginsVersion
+import org.gradle.kotlin.dsl.support.serviceOf
+
 plugins {
    `kotlin-dsl`
 }
@@ -13,3 +20,82 @@ tasks.withType<AbstractArchiveTask>().configureEach {
    isPreserveFileTimestamps = false
    isReproducibleFileOrder = true
 }
+
+//region workaround for https://github.com/gradle/gradle/issues/13020
+// Gradle _always_ logs an annoying warning: Unsupported Kotlin plugin version.
+// The warning is always logged, no matter what, and it doesn't ever seem to represent an actual problem.
+// So, this code downloads the original EmbeddedKotlinPlugin and disables the warning.
+// Because Gradle's classloader is hierarchical, the original will be replaced.
+
+val kotlinDslPluginSources: Configuration by configurations.creating {
+   description = "Download the original Gradle Kotlin DSL plugin source code."
+   isCanBeConsumed = false
+   isCanBeResolved = false
+   isCanBeDeclared = true
+   isVisible = false
+   defaultDependencies {
+      add(project.dependencies.create("org.gradle.kotlin:gradle-kotlin-dsl-plugins:$expectedKotlinDslPluginsVersion"))
+   }
+}
+
+val kotlinDslPluginSourcesResolver: Configuration by configurations.creating {
+   description = "Resolve files from ${kotlinDslPluginSources.name}."
+   isCanBeConsumed = false
+   isCanBeResolved = true
+   isCanBeDeclared = false
+   isVisible = false
+   extendsFrom(kotlinDslPluginSources)
+   attributes {
+      attribute(DOCS_TYPE_ATTRIBUTE, objects.named(SOURCES))
+   }
+}
+
+val fixGradlePluginWarning by tasks.registering {
+   description = "Download EmbeddedKotlinPlugin.kt and patch it to disable the warning."
+
+   val src = kotlinDslPluginSourcesResolver.incoming.files
+   inputs.files(src).withNormalizer(ClasspathNormalizer::class)
+
+   outputs.dir(temporaryDir).withPropertyName("outputDir")
+
+   val archives = serviceOf<ArchiveOperations>()
+
+   doLast {
+      val embeddedKotlinPlugin = src.flatMap { s ->
+         archives.zipTree(s).matching {
+            include("**/EmbeddedKotlinPlugin.kt")
+         }
+      }.firstOrNull()
+
+      if (embeddedKotlinPlugin == null) {
+         // If EmbeddedKotlinPlugin.kt can't be found then maybe this workaround
+         // is no longer necessary, or it needs to be updated.
+         logger.warn("[$path] could not find EmbeddedKotlinPlugin.kt in $src")
+      } else {
+         logger.info("[$path] Patching EmbeddedKotlinPlugin.kt to remove 'Unsupported Kotlin plugin version' warning")
+         temporaryDir.deleteRecursively()
+         temporaryDir.mkdirs()
+         temporaryDir.resolve(embeddedKotlinPlugin.name).apply {
+            writeText(
+               embeddedKotlinPlugin.readText()
+                  // This is the key change: converting 'warn' into 'info'.
+                  .replace("\n        warn(\n", "\n        info(\n")
+                  // Mark internal things as internal to prevent compiler warnings about unused code,
+                  // and to stop them leaking into build scripts.
+                  .replace("\n\nfun Logger.", "\n\nprivate fun Logger.")
+                  .replace(
+                     "*/\nabstract class EmbeddedKotlinPlugin",
+                     "*/\ninternal abstract class EmbeddedKotlinPlugin"
+                  )
+            )
+         }
+      }
+   }
+}
+
+sourceSets {
+   main {
+      kotlin.srcDir(fixGradlePluginWarning)
+   }
+}
+//endregion