Don't add explicitApi mode for test sources

^KT-58571 Fixed

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

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.gradle
 import org.gradle.api.logging.LogLevel
 import org.gradle.util.GradleVersion
 import org.jetbrains.kotlin.gradle.testbase.*
+import org.jetbrains.kotlin.gradle.util.AGPVersion
 import org.jetbrains.kotlin.konan.target.HostManager
 import org.jetbrains.kotlin.konan.target.KonanTarget
 import org.junit.jupiter.api.DisplayName
@@ -37,6 +38,12 @@ class ExplicitApiIT : KGPBaseTest() {
 
                 assertCompilerArgument(":compileKotlin", "-Xexplicit-api=warning")
             }
+
+            build(":compileTestKotlin") {
+                assertTasksExecuted(":compileTestKotlin")
+
+                assertNoCompilerArgument(":compileTestKotlin", "-Xexplicit-api=warning")
+            }
         }
     }
 
@@ -142,4 +149,45 @@ class ExplicitApiIT : KGPBaseTest() {
             }
         }
     }
+
+    @DisplayName("Explicit api mode is enabled only for non-test variants in Android project")
+    @AndroidGradlePluginTests
+    @GradleAndroidTest
+    fun explicitApiAndroid(
+        gradleVersion: GradleVersion,
+        agpVersion: String,
+        jdkVersion: JdkVersions.ProvidedJdk
+    ) {
+        project(
+            "AndroidSimpleApp",
+            gradleVersion,
+            buildOptions = defaultBuildOptions.copy(
+                androidVersion = agpVersion,
+                logLevel = LogLevel.DEBUG
+            ),
+            buildJdk = jdkVersion.location
+        ) {
+
+            buildGradle.appendText(
+                //language=groovy
+                """
+                |
+                |kotlin.explicitApiWarning()
+                |
+                """.trimMargin()
+            )
+
+            build(":compileDebugKotlin") {
+                assertTasksExecuted(":compileDebugKotlin")
+
+                assertCompilerArgument(":compileDebugKotlin", "-Xexplicit-api=warning")
+            }
+
+            build(":compileDebugUnitTestKotlin") {
+                assertTasksExecuted(":compileDebugUnitTestKotlin")
+
+                assertNoCompilerArgument(":compileDebugUnitTestKotlin", "-Xexplicit-api=warning")
+            }
+        }
+    }
 }

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

@@ -254,6 +254,22 @@ fun BuildResult.assertCompilerArgument(
     }
 }
 
+fun BuildResult.assertNoCompilerArgument(
+    taskPath: String,
+    notExpectedArgument: String,
+) {
+    val taskOutput = getOutputForTask(taskPath)
+    val compilerArguments = taskOutput.lines().first {
+        it.contains("Kotlin compiler args:")
+    }.substringAfter("Kotlin compiler args:")
+
+    assert(!compilerArguments.contains(notExpectedArgument)) {
+        printBuildOutput()
+
+        "$taskPath task compiler arguments contains $notExpectedArgument. Actual content: $compilerArguments"
+    }
+}
+
 /**
  * Asserts command line arguments of the given K/N compiler for given tasks' paths
  *

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/KotlinNativeTargetConfigurator.kt

@@ -20,6 +20,7 @@ import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.Exec
 import org.gradle.api.tasks.TaskProvider
 import org.gradle.language.base.plugins.LifecycleBasePlugin
+import org.jetbrains.kotlin.gradle.dsl.ExplicitApiMode
 import org.jetbrains.kotlin.gradle.dsl.KotlinNativeCompilerOptions
 import org.jetbrains.kotlin.gradle.dsl.topLevelExtension
 import org.jetbrains.kotlin.gradle.plugin.KotlinCompilation.Companion.TEST_COMPILATION_NAME
@@ -404,7 +405,17 @@ open class KotlinNativeTargetConfigurator<T : KotlinNativeTarget> : AbstractKotl
                 it.runViaBuildToolsApi.value(false).disallowChanges() // K/N is not yet supported
 
                 it.explicitApiMode
-                    .value(project.providers.provider { ext.explicitApi })
+                    .value(
+                        project.providers.provider {
+                            // Plugin explicitly does not configures 'explicitApi' mode for test sources
+                            // compilation, as test sources are not published
+                            if (compilationInfo.isMain) {
+                                ext.explicitApi
+                            } else {
+                                ExplicitApiMode.Disabled
+                            }
+                        }
+                    )
                     .finalizeValueOnRead()
             }
 

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/tasks/AbstractKotlinCompile.kt

@@ -112,7 +112,7 @@ abstract class AbstractKotlinCompile<T : CommonCompilerArguments> @Inject constr
 
     @get:Input
     @get:Optional
-    internal abstract val explicitApiMode: Property<ExplicitApiMode>
+    abstract val explicitApiMode: Property<ExplicitApiMode>
 
     @get:Internal
     internal abstract val suppressKotlinOptionsFreeArgsModificationWarning: Property<Boolean>

libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/tasks/configuration/AbstractKotlinCompileConfig.kt

@@ -14,6 +14,7 @@ import org.gradle.api.provider.ProviderFactory
 import org.gradle.api.tasks.TaskProvider
 import org.jetbrains.kotlin.compilerRunner.CompilerSystemPropertiesService
 import org.jetbrains.kotlin.compilerRunner.GradleCompilerRunner
+import org.jetbrains.kotlin.gradle.dsl.ExplicitApiMode
 import org.jetbrains.kotlin.gradle.dsl.KotlinTopLevelExtension
 import org.jetbrains.kotlin.gradle.dsl.topLevelExtension
 import org.jetbrains.kotlin.gradle.incremental.IncrementalModuleInfoBuildService
@@ -21,6 +22,8 @@ import org.jetbrains.kotlin.gradle.internal.ClassLoadersCachingBuildService
 import org.jetbrains.kotlin.gradle.internal.KaptGenerateStubsTask
 import org.jetbrains.kotlin.gradle.plugin.*
 import org.jetbrains.kotlin.gradle.plugin.PropertiesProvider.Companion.kotlinPropertiesProvider
+import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinJvmAndroidCompilation
+import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinMetadataTarget
 import org.jetbrains.kotlin.gradle.plugin.mpp.associateWithClosure
 import org.jetbrains.kotlin.gradle.plugin.mpp.internal
 import org.jetbrains.kotlin.gradle.plugin.sources.applyLanguageSettingsToCompilerOptions
@@ -162,6 +165,28 @@ internal abstract class AbstractKotlinCompileConfig<TASK : AbstractKotlinCompile
                     }
                 }
             )
+
+            task.explicitApiMode
+                .value(
+                    project.providers.provider {
+                        // Plugin explicitly does not configures 'explicitApi' mode for test sources
+                        // compilation, as test sources are not published
+                        val compilation = compilationInfo.tcsOrNull?.compilation
+                        val isCommonCompilation = compilation?.target is KotlinMetadataTarget
+
+                        val androidCompilation = compilationInfo.tcsOrNull?.compilation as? KotlinJvmAndroidCompilation
+                        val isMainAndroidCompilation = androidCompilation?.let {
+                            getTestedVariantData(it.androidVariant) == null
+                        } ?: false
+
+                        if (compilationInfo.isMain || isCommonCompilation || isMainAndroidCompilation) {
+                            ext.explicitApi
+                        } else {
+                            ExplicitApiMode.Disabled
+                        }
+                    }
+                )
+                .finalizeValueOnRead()
         }
     }
 }