Test Gradle buildSrc with kotlin-gradle-plugin-api dependency

For ^KT-46517

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/KotlinGradlePluginIT.kt

@@ -743,6 +743,17 @@ class KotlinGradleIT : BaseGradleIT() {
         }
     }
 
+    @Test
+    fun testKotlinPluginDependenciesInBuildSrc() {
+        val project = transformProjectWithPluginsDsl("kotlinPluginDepsInBuildSrc")
+        project.setupWorkingDir()
+        project.build("build") {
+            assertSuccessful()
+            assertContains("Hi from BuildSrc")
+        }
+
+    }
+
     @Test
     fun testInternalTest() = with(
         Project("internalTest")

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlinPluginDepsInBuildSrc/build.gradle.kts

@@ -0,0 +1,15 @@
+import foo.bar.configureFromBuildSrc
+
+plugins {
+    kotlin("jvm") version "<pluginMarkerVersion>"
+}
+
+kotlin {
+    sourceSets {
+        main {
+            languageSettings {
+                configureFromBuildSrc()
+            }
+        }
+    }
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlinPluginDepsInBuildSrc/buildSrc/build.gradle.kts

@@ -0,0 +1,14 @@
+plugins {
+    kotlin("jvm") version "<pluginMarkerVersion>"
+}
+
+repositories {
+    mavenCentral()
+    mavenLocal()
+}
+
+allprojects {
+    dependencies {
+        implementation("org.jetbrains.kotlin:kotlin-gradle-plugin-api:<pluginMarkerVersion>")
+    }
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlinPluginDepsInBuildSrc/buildSrc/settings.gradle.kts

@@ -0,0 +1,6 @@
+pluginManagement {
+    repositories {
+        mavenCentral()
+        mavenLocal()
+    }
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlinPluginDepsInBuildSrc/buildSrc/src/main/kotlin/SomeHelper.kt

@@ -0,0 +1,7 @@
+package foo.bar
+
+import org.jetbrains.kotlin.gradle.plugin.LanguageSettingsBuilder
+
+fun LanguageSettingsBuilder.configureFromBuildSrc() {
+    println("Hi from BuildSrc: $this")
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kotlinPluginDepsInBuildSrc/settings.gradle.kts

@@ -0,0 +1,7 @@
+
+pluginManagement {
+    repositories {
+        mavenCentral()
+        mavenLocal()
+    }
+}