[IC] Multi-module incremental compilation smoke tests for KMP

Part 2. Main multi-module KMP smoke tests for incremental compilation

^KT-56963 Fixed
^KT-63876 Fixed

Merge-request: KT-MR-13193
Merged-by: Evgenii Mazhukin <evgenii.mazhukin@jetbrains.com>

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

@@ -9,15 +9,13 @@ import org.gradle.api.logging.LogLevel
 import org.gradle.testkit.runner.BuildResult
 import org.gradle.util.GradleVersion
 import org.jetbrains.kotlin.gradle.testbase.*
-import org.jetbrains.kotlin.gradle.testbase.relativizeTo
+import org.jetbrains.kotlin.gradle.util.replaceWithVersion
 import java.nio.file.Path
-import java.util.concurrent.atomic.AtomicInteger
-import kotlin.io.path.appendText
 
 /**
- * KmpIncrementalITBase is used as a "limited scope" for experimental test utils.
- * If some of them can be reused widely, consider moving them to KGPBaseTest
- * or the appropriate util package. //TODO: KT-63876
+ * Convenience class for KMP incremental compilation tests.
+ *
+ * Consider moving all general-purpose logic to `org.jetbrains.kotlin.gradle.testbase` package.
  */
 abstract class KmpIncrementalITBase : KGPBaseTest() {
 
@@ -27,9 +25,11 @@ abstract class KmpIncrementalITBase : KGPBaseTest() {
     protected open val gradleTask = "assemble"
     protected open val projectName = "generic-kmp-app-plus-lib-with-tests"
     protected open val mainCompileTasks = setOf(
+        ":app:compileCommonMainKotlinMetadata",
         ":app:compileKotlinJvm",
         ":app:compileKotlinJs",
         ":app:compileKotlinNative",
+        ":lib:compileCommonMainKotlinMetadata",
         ":lib:compileKotlinJvm",
         ":lib:compileKotlinJs",
         ":lib:compileKotlinNative",
@@ -48,30 +48,30 @@ abstract class KmpIncrementalITBase : KGPBaseTest() {
         return subProject(subproject).kotlinSourcesDir(srcDir).resolve(name)
     }
 
-    protected fun Path.addPrivateVal(): Path {
-        this@addPrivateVal.appendText("private val nothingMuch${changeCounter.incrementAndGet()} = 24")
-        return this@addPrivateVal
-    }
-
-    protected open fun BuildResult.assertSuccessOrUTD(allTasks: Set<String>, executedTasks: Set<String>) {
-        assertTasksExecuted(executedTasks)
-        assertTasksUpToDate(allTasks - executedTasks)
-    }
-
-    protected open fun TestProject.testCase(incrementalPath: Path? = null, executedTasks: Set<String>, assertions: BuildResult.() -> Unit = {}) {
+    protected open fun TestProject.checkIncrementalBuild(
+        tasksExpectedToExecute: Set<String>,
+        assertions: BuildResult.() -> Unit = {}
+    ) {
         build(gradleTask, buildOptions = defaultBuildOptions.copy(logLevel = LogLevel.DEBUG)) {
-            assertSuccessOrUTD(
-                allTasks = mainCompileTasks,
-                executedTasks = executedTasks
-            )
-            incrementalPath?.let {
-                assertIncrementalCompilation(listOf(it).relativizeTo(projectPath))
-            }
+            assertTasksExecuted(tasksExpectedToExecute)
+            assertTasksUpToDate(mainCompileTasks - tasksExpectedToExecute)
             assertions()
         }
     }
 
-    companion object {
-        private val changeCounter = AtomicInteger(0)
+    protected open fun TestProject.multiStepCheckIncrementalBuilds(
+        incrementalPath: Path,
+        steps: List<String>,
+        tasksExpectedToExecuteOnEachStep: Set<String>,
+        afterEachStep: BuildResult.() -> Unit = {}
+    ) {
+        for (step in steps) {
+            incrementalPath.replaceWithVersion(step)
+            build(gradleTask, buildOptions = defaultBuildOptions.copy(logLevel = LogLevel.DEBUG)) {
+                assertTasksExecuted(tasksExpectedToExecuteOnEachStep)
+                assertTasksUpToDate(mainCompileTasks - tasksExpectedToExecuteOnEachStep)
+                afterEachStep()
+            }
+        }
     }
-}
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/mpp/smoke/BasicIncrementalCompilationIT.kt

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.gradle.mpp.smoke
 import org.gradle.util.GradleVersion
 import org.jetbrains.kotlin.gradle.mpp.KmpIncrementalITBase
 import org.jetbrains.kotlin.gradle.testbase.*
+import org.jetbrains.kotlin.test.TestMetadata
 import org.junit.jupiter.api.DisplayName
 
 /**
@@ -19,6 +20,7 @@ open class BasicIncrementalCompilationIT : KmpIncrementalITBase() {
 
     @DisplayName("Base test case - local change, local recompilation")
     @GradleTest
+    @TestMetadata("generic-kmp-app-plus-lib-with-tests")
     fun testStrictlyLocalChange(gradleVersion: GradleVersion): Unit = withProject(gradleVersion) {
         build("assemble")
 
@@ -26,84 +28,99 @@ open class BasicIncrementalCompilationIT : KmpIncrementalITBase() {
          * Step 1: touch app:common, no abi change
          */
 
-        testCase(
-            incrementalPath = resolvePath("app", "commonMain", "Unused.kt").addPrivateVal(),
-            executedTasks = setOf(
+        val sourceInAppCommon = resolvePath("app", "commonMain", "Unused.kt").addPrivateVal()
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(
+                ":app:compileCommonMainKotlinMetadata",
                 ":app:compileKotlinJvm",
                 ":app:compileKotlinJs",
                 ":app:compileKotlinNative"
             )
-        )
+        ) {
+            assertIncrementalCompilation(listOf(sourceInAppCommon).relativizeTo(projectPath))
+        }
 
         /**
          * Step 2: touch app:jvm, no abi change
          */
 
-        val appJvmClassKt = resolvePath("app", "jvmMain", "UnusedJvm.kt").addPrivateVal()
-        testCase(
-            incrementalPath = null, //TODO: it just doesn't print "Incremental compilation completed", why? (KT-63476)
-            executedTasks = setOf(":app:compileKotlinJvm")
+        val sourceInAppJvm = resolvePath("app", "jvmMain", "UnusedJvm.kt").addPrivateVal()
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(":app:compileKotlinJvm")
         ) {
-            assertCompiledKotlinSources(listOf(appJvmClassKt).relativizeTo(projectPath), output)
+            //TODO: it just doesn't print "Incremental compilation completed", why? (KT-63476)
+            assertCompiledKotlinSources(listOf(sourceInAppJvm).relativizeTo(projectPath), output)
         }
 
         /**
          * Step 3: touch app:js, no abi change
          */
 
-        testCase(
-            incrementalPath = resolvePath("app", "jsMain", "UnusedJs.kt").addPrivateVal(),
-            executedTasks = setOf(":app:compileKotlinJs"),
-        )
+        val sourceInAppJs = resolvePath("app", "jsMain", "UnusedJs.kt").addPrivateVal()
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(":app:compileKotlinJs"),
+        ) {
+            assertIncrementalCompilation(listOf(sourceInAppJs).relativizeTo(projectPath))
+        }
 
         /**
          * Step 4: touch app:native, no abi change
          */
 
         resolvePath("app", "nativeMain", "UnusedNative.kt").addPrivateVal()
-        testCase(
-            incrementalPath = null, // no native incremental compilation - see KT-62824
-            executedTasks = setOf(":app:compileKotlinNative"),
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(":app:compileKotlinNative"),
         )
 
         /**
          * Step 5: touch lib:common, no abi change
          */
 
-        testCase(
-            incrementalPath = resolvePath("lib", "commonMain", "UsedInLibPlatformTests.kt").addPrivateVal(),
-            executedTasks = mainCompileTasks // TODO: KT-62642 - bad compile avoidance here
-        )
+        val sourceInLibCommon = resolvePath("lib", "commonMain", "UsedInLibPlatformTests.kt").addPrivateVal()
+        checkIncrementalBuild(
+            tasksExpectedToExecute = mainCompileTasks // TODO: KT-62642 - bad compile avoidance here
+        ) {
+            assertIncrementalCompilation(listOf(sourceInLibCommon).relativizeTo(projectPath))
+        }
 
         /**
          * Step 6: touch lib:jvm, no abi change
          */
 
-        val libJvmUtilKt = resolvePath("lib", "jvmMain", "UsedInAppJvmAndLibTests.kt").addPrivateVal()
-        testCase(
-            incrementalPath = null, //TODO: it just doesn't print "Incremental compilation completed", why? (KT-63476)
-            executedTasks = setOf(":app:compileKotlinJvm", ":lib:compileKotlinJvm"),
+        val sourceInLibJvm = resolvePath("lib", "jvmMain", "UsedInAppJvmAndLibTests.kt").addPrivateVal()
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(
+                ":app:compileKotlinJvm",
+                ":lib:compileKotlinJvm"
+            ),
         ) {
-            assertCompiledKotlinSources(listOf(libJvmUtilKt).relativizeTo(projectPath), output)
+            assertCompiledKotlinSources(listOf(sourceInLibJvm).relativizeTo(projectPath), output)
         }
 
         /**
          * Step 7: touch lib:js, no abi change
          */
 
-        testCase(
-            incrementalPath = resolvePath("lib", "jsMain", "UsedInAppJsAndLibTests.kt").addPrivateVal(),
-            executedTasks = setOf(":app:compileKotlinJs", ":lib:compileKotlinJs"),
-        )
+        val sourceInLibJs = resolvePath("lib", "jsMain", "UsedInAppJsAndLibTests.kt").addPrivateVal()
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(
+                ":app:compileKotlinJs",
+                ":lib:compileKotlinJs"
+            ),
+        ) {
+            assertIncrementalCompilation(listOf(sourceInLibJs).relativizeTo(projectPath))
+        }
 
         /**
          * Step 8: touch lib:native, no abi change
          */
 
         resolvePath("lib", "nativeMain", "UsedInAppNativeAndLibTests.kt").addPrivateVal()
-        testCase(
-            incrementalPath = null,
-            executedTasks = setOf(":app:compileKotlinNative", ":lib:compileKotlinNative"),
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(
+                ":app:compileKotlinNative",
+                ":lib:compileKotlinNative"
+            ),
         )
     }
 }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/mpp/smoke/BasicTestIncrementalCompilationIT.kt

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.gradle.mpp.smoke
 import org.gradle.util.GradleVersion
 import org.jetbrains.kotlin.gradle.mpp.KmpIncrementalITBase
 import org.jetbrains.kotlin.gradle.testbase.*
+import org.jetbrains.kotlin.test.TestMetadata
 import org.junit.jupiter.api.DisplayName
 
 @DisplayName("Basic incremental scenarios with tests in KMP - K2")
@@ -15,6 +16,9 @@ import org.junit.jupiter.api.DisplayName
 open class BasicTestIncrementalCompilationIT : KmpIncrementalITBase() {
     override val mainCompileTasks: Set<String>
         get() = setOf(
+            ":app:compileCommonMainKotlinMetadata",
+            ":lib:compileCommonMainKotlinMetadata",
+
             ":app:compileTestKotlinJvm",
             ":lib:compileTestKotlinJvm",
 
@@ -38,6 +42,7 @@ open class BasicTestIncrementalCompilationIT : KmpIncrementalITBase() {
 
     @DisplayName("KMP tests are rebuilt when affected")
     @GradleTest
+    @TestMetadata("generic-kmp-app-plus-lib-with-tests")
     fun testAffectingTestDependencies(gradleVersion: GradleVersion): Unit = withProject(gradleVersion) {
         build("build")
 
@@ -45,18 +50,21 @@ open class BasicTestIncrementalCompilationIT : KmpIncrementalITBase() {
          * Step 1 - touch lib/common, affect all tests in app and lib
          */
 
-        testCase(
-            incrementalPath = resolvePath("lib", "commonMain", "UsedInLibPlatformTests.kt").addPrivateVal(),
-            executedTasks = mainCompileTasks,
-        )
+        val changedInLibCommon = resolvePath("lib", "commonMain", "UsedInLibPlatformTests.kt").addPrivateVal()
+        checkIncrementalBuild(
+            tasksExpectedToExecute = mainCompileTasks,
+        ) {
+            assertIncrementalCompilation(listOf(changedInLibCommon).relativizeTo(projectPath))
+        }
 
         /**
          * Step 2 - touch app/common, affect all tests in app
          */
 
-        testCase(
-            incrementalPath = resolvePath("app", "commonMain", "Unused.kt").addPrivateVal(),
-            executedTasks = setOf(
+        val changedInAppCommon = resolvePath("app", "commonMain", "Unused.kt").addPrivateVal()
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(
+                ":app:compileCommonMainKotlinMetadata",
                 ":app:compileTestKotlinJvm",
                 ":app:compileTestKotlinNative",
                 ":app:compileTestKotlinJs",
@@ -64,16 +72,17 @@ open class BasicTestIncrementalCompilationIT : KmpIncrementalITBase() {
                 ":app:jvmTest",
                 ":app:nativeTest",
             ),
-        )
+        ) {
+            assertIncrementalCompilation(listOf(changedInAppCommon).relativizeTo(projectPath))
+        }
 
         /**
          * Step 3 - touch app/jvm, affect jvm tests in app
          */
 
         val touchedAppJvm = resolvePath("app", "jvmMain", "UnusedJvm.kt").addPrivateVal()
-        testCase(
-            incrementalPath = null,
-            executedTasks = setOf(
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(
                 ":app:compileTestKotlinJvm",
                 ":app:jvmTest",
             ),
@@ -85,22 +94,23 @@ open class BasicTestIncrementalCompilationIT : KmpIncrementalITBase() {
          * Step 4 - touch app/js, affect js tests in app
          */
 
-        testCase(
-            incrementalPath = resolvePath("app", "jsMain", "UnusedJs.kt").addPrivateVal(),
-            executedTasks = setOf(
+        val changedInAppJs = resolvePath("app", "jsMain", "UnusedJs.kt").addPrivateVal()
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(
                 ":app:compileTestKotlinJs",
                 ":app:jsTest",
             ),
-        )
+        ) {
+            assertIncrementalCompilation(listOf(changedInAppJs).relativizeTo(projectPath))
+        }
 
         /**
          * Step 5 - touch app/native, affect native tests in app
          */
 
         resolvePath("app", "nativeMain", "UnusedNative.kt").addPrivateVal()
-        testCase(
-            incrementalPath = null,
-            executedTasks = setOf(
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(
                 ":app:compileTestKotlinNative",
                 ":app:nativeTest",
             ),

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/mpp/smoke/ExpectActualIncrementalCompilationIT.kt

@@ -8,17 +8,15 @@ package org.jetbrains.kotlin.gradle.mpp.smoke
 import org.gradle.api.logging.LogLevel
 import org.gradle.util.GradleVersion
 import org.jetbrains.kotlin.gradle.testbase.*
-import org.jetbrains.kotlin.gradle.util.replaceFirst
+import org.jetbrains.kotlin.gradle.util.replaceWithVersion
+import org.jetbrains.kotlin.test.TestMetadata
 import org.junit.jupiter.api.DisplayName
-import kotlin.io.path.appendText
 
 /**
- *
  * Touch file with expect fun, target IC adds actual to the build set
  * Variants: expect class
  * Touch file with actual fun, target IC adds expect to the build set
  * Variants: expect class
- *
  */
 @DisplayName("Incremental scenarios with expect/actual - K2")
 @MppGradlePluginTests
@@ -28,17 +26,21 @@ open class ExpectActualIncrementalCompilationIT : KGPBaseTest() {
 
     @DisplayName("File with actual declaration needs recompiling")
     @GradleTest
+    @TestMetadata("expect-actual-fun-or-class-ic")
     fun testRecompilationOfActualFun(gradleVersion: GradleVersion) {
         nativeProject("expect-actual-fun-or-class-ic", gradleVersion) {
             build("assemble")
 
             listOf(
                 kotlinSourcesDir("jvmMain").resolve("ActualFunFoo.kt"),
-                kotlinSourcesDir("nativeMain").resolve("ActualFunFoo.kt"),
                 kotlinSourcesDir("jsMain").resolve("ActualFunFoo.kt")
             ).forEach {
-                it.replaceFirst("\"foo", "\"bar")
+                // just touch the file. expected logic is this:
+                // actual declaration needs to be recompiled -> we add expect declaration to the list of compiled files
+                it.addPrivateVal()
             }
+            //TODO: KT-63970 - native compilation fails, if val is private
+            kotlinSourcesDir("nativeMain").resolve("ActualFunFoo.kt").addPublicVal()
 
             build("assemble", buildOptions = defaultBuildOptions.copy(logLevel = LogLevel.DEBUG)) {
                 assertTasksExecuted(":compileKotlinJvm", ":compileKotlinJs", ":compileKotlinNative")
@@ -55,15 +57,13 @@ open class ExpectActualIncrementalCompilationIT : KGPBaseTest() {
 
     @DisplayName("File with expect declaration needs recompiling indirectly")
     @GradleTest
+    @TestMetadata("expect-actual-fun-or-class-ic")
     fun testRecompilationOfExpectFun(gradleVersion: GradleVersion) {
         nativeProject("expect-actual-fun-or-class-ic", gradleVersion) {
             build("assemble")
 
-            val unusedKtPath = kotlinSourcesDir("commonMain").resolve("Unused.kt")
-            unusedKtPath.replaceFirst(
-                "val secret = 1",
-                "val secret = \"k2\""
-            )
+            val commonSourceKt = kotlinSourcesDir("commonMain").resolve("UsedInFileWithExpectFun.kt")
+            commonSourceKt.replaceWithVersion("sourceCompatibleAbiChange")
 
             build("assemble", buildOptions = defaultBuildOptions.copy(logLevel = LogLevel.DEBUG)) {
                 assertTasksExecuted(":compileKotlinJvm", ":compileKotlinJs", ":compileKotlinNative")
@@ -72,7 +72,7 @@ open class ExpectActualIncrementalCompilationIT : KGPBaseTest() {
                         kotlinSourcesDir("jvmMain").resolve("ActualFunFoo.kt"),
                         kotlinSourcesDir("jsMain").resolve("ActualFunFoo.kt"),
                         kotlinSourcesDir("commonMain").resolve("ExpectFunFoo.kt"),
-                        unusedKtPath
+                        commonSourceKt
                     ).relativizeTo(projectPath)
                 )
             }
@@ -81,11 +81,12 @@ open class ExpectActualIncrementalCompilationIT : KGPBaseTest() {
 
     @DisplayName("File with expect class declaration needs recompiling")
     @GradleTest
+    @TestMetadata("expect-actual-fun-or-class-ic")
     fun testRecompilationOfExpectClass(gradleVersion: GradleVersion) {
         nativeProject("expect-actual-fun-or-class-ic", gradleVersion) {
             build("assemble")
 
-            kotlinSourcesDir("commonMain").resolve("ExpectClassBar.kt").appendText("val irrelevant = 2")
+            kotlinSourcesDir("commonMain").resolve("ExpectClassBar.kt").addPrivateVal()
 
             build("assemble", buildOptions = defaultBuildOptions.copy(logLevel = LogLevel.DEBUG)) {
                 assertTasksExecuted(":compileKotlinJvm", ":compileKotlinJs", ":compileKotlinNative")

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/mpp/smoke/MultiModuleIncrementalCompilationIT.kt

@@ -5,62 +5,237 @@
 
 package org.jetbrains.kotlin.gradle.mpp.smoke
 
+import org.gradle.api.logging.LogLevel
+import org.gradle.testkit.runner.BuildResult
 import org.gradle.util.GradleVersion
-import org.jetbrains.kotlin.gradle.testbase.BuildOptions
-import org.jetbrains.kotlin.gradle.testbase.GradleTest
-import org.jetbrains.kotlin.gradle.testbase.KGPBaseTest
-import org.jetbrains.kotlin.gradle.testbase.MppGradlePluginTests
-import org.junit.jupiter.api.Disabled
+import org.jetbrains.kotlin.gradle.mpp.KmpIncrementalITBase
+import org.jetbrains.kotlin.gradle.testbase.*
+import org.jetbrains.kotlin.gradle.util.replaceWithVersion
+import org.jetbrains.kotlin.test.TestMetadata
 import org.junit.jupiter.api.DisplayName
 
-@Disabled("KT-56963")
+/**
+ * Multi-module KMP tests assert that IC is fine, when API changes between two modules, or common/platform parts of a module.
+ */
 @DisplayName("Basic multi-module incremental scenarios with KMP - K2")
 @MppGradlePluginTests
-open class MultiModuleIncrementalCompilationIT : KGPBaseTest() {
-    override val defaultBuildOptions: BuildOptions
-        get() = super.defaultBuildOptions.copyEnsuringK2()
+open class MultiModuleIncrementalCompilationIT : KmpIncrementalITBase() {
 
+    /**
+     * Tests api change across the module + sourceSet boundary
+     */
     @DisplayName("Verify IC builds on change in lib/commonMain")
     @GradleTest
-    fun testTouchLibCommon(gradleVersion: GradleVersion) {
-        /**
-         * [Cross-Module] touch libCommon, affect appCommon, appJs
-         * Variants: 1. code-compatible ABI breakage (change deduced return type), 2. no ABI breakage, 3. error + fix
-         */
+    @TestMetadata("generic-kmp-app-plus-lib-with-tests")
+    fun testTouchLibCommon(gradleVersion: GradleVersion) = withProject(gradleVersion) {
+        build("assemble")
 
+        /**
+         * Step 1: touch util used in app common
+         */
+        val usedInAppCommon = resolvePath("lib", "commonMain", "UsedInAppCommon.kt")
+
+        multiStepCheckIncrementalBuilds(
+            incrementalPath = usedInAppCommon,
+            steps = listOf(
+                "1_addUnusedParameter",
+                "2_changeReturnType"
+            ),
+            tasksExpectedToExecuteOnEachStep = mainCompileTasks,
+            afterEachStep = {
+                assertIncrementalCompilation(
+                    listOf(
+                        usedInAppCommon,
+                        resolvePath("app", "commonMain", "DependsOnLibCommon.kt")
+                    ).relativizeTo(projectPath)
+                )
+            }
+        )
+
+        /**
+         * Step 2: touch class extended in app platform, then build each platform
+         */
+        val usedInAppPlatform = resolvePath("lib", "commonMain", "UsedInAppPlatform.kt")
+        usedInAppPlatform.replaceWithVersion("1_addNewPublicApi")
+
+        fun testIndividualTarget(moduleTask: String, extraAssertions: BuildResult.() -> Unit = {}) {
+            build(":app:$moduleTask", buildOptions = defaultBuildOptions.copy(logLevel = LogLevel.DEBUG)) {
+                val targetTasks = setOf(
+                    ":app:$moduleTask",
+                    ":lib:$moduleTask"
+                )
+                assertTasksExecuted(targetTasks)
+                assertTasksAreNotInTaskGraph(*(mainCompileTasks - targetTasks).toTypedArray())
+                extraAssertions()
+            }
+        }
+
+        testIndividualTarget("compileKotlinJvm") {
+            assertCompiledKotlinSources(
+                listOf(
+                    usedInAppPlatform,
+                    resolvePath("app", "jvmMain", "DependsOnLibCommon.kt")
+                ).relativizeTo(projectPath),
+                output
+            )
+        }
+        testIndividualTarget("compileKotlinJs") {
+            assertIncrementalCompilation(
+                listOf(
+                    usedInAppPlatform,
+                    resolvePath("app", "jsMain", "DependsOnLibCommon.kt")
+                ).relativizeTo(projectPath)
+            )
+        }
+        testIndividualTarget("compileKotlinNative")
     }
 
+    /**
+     * Three platforms, two steps for each. Do source-compatible changes: first add default parameter,
+     * then change return type.
+     * lib/platform utils are used in app/platform with deduced return type.
+     */
     @DisplayName("Verify IC builds on change in lib/platformMain")
     @GradleTest
-    fun testTouchLibPlatform(gradleVersion: GradleVersion) {
-        /**
-         * [C-M] touch lbJs, affect appJs
-         * Variants: 1. code-compatible ABI breakage (change deduced return type), 2. no ABI breakage, 3. error + fix
-         */
+    @TestMetadata("generic-kmp-app-plus-lib-with-tests")
+    fun testTouchLibPlatform(gradleVersion: GradleVersion) = withProject(gradleVersion) {
+        build("assemble")
 
+        val commonSteps = listOf("1_addUnusedParameter", "2_changeReturnType")
+
+        /**
+         * Step 1 - jvm
+         */
+        val jvmUtil = resolvePath("lib", "jvmMain", "UsedInAppJvmAndLibTests.kt")
+        multiStepCheckIncrementalBuilds(
+            incrementalPath = jvmUtil,
+            steps = commonSteps,
+            tasksExpectedToExecuteOnEachStep = setOf(
+                ":app:compileKotlinJvm",
+                ":lib:compileKotlinJvm"
+            ),
+            afterEachStep = {
+                assertCompiledKotlinSources(
+                    expectedSources = listOf(
+                        jvmUtil,
+                        resolvePath("app", "jvmMain", "DependsOnLibJvm.kt")
+                    ).relativizeTo(projectPath),
+                    output = output
+                )
+            }
+        )
+
+        /**
+         * Step 2 - js
+         */
+        val jsUtil = resolvePath("lib", "jsMain", "UsedInAppJsAndLibTests.kt")
+        multiStepCheckIncrementalBuilds(
+            incrementalPath = jsUtil,
+            steps = commonSteps,
+            tasksExpectedToExecuteOnEachStep = setOf(
+                ":app:compileKotlinJs",
+                ":lib:compileKotlinJs"
+            ),
+            afterEachStep = {
+                assertIncrementalCompilation(
+                    listOf(
+                        jsUtil,
+                        resolvePath("app", "jsMain", "DependsOnLibJs.kt")
+                    ).relativizeTo(projectPath)
+                )
+            }
+        )
+
+        /**
+         * Step 3 - native
+         */
+        val nativeUtil = resolvePath("lib", "nativeMain", "UsedInAppNativeAndLibTests.kt")
+        multiStepCheckIncrementalBuilds(
+            incrementalPath = nativeUtil,
+            steps = commonSteps,
+            tasksExpectedToExecuteOnEachStep = setOf(
+                ":app:compileKotlinNative",
+                ":lib:compileKotlinNative"
+            )
+        )
     }
 
+    /**
+     * Main smoke tests for api changes on the source set boundary
+     */
     @DisplayName("Verify IC builds on change in app/commonMain")
     @GradleTest
-    fun testTouchAppCommon(gradleVersion: GradleVersion) {
-        /**
-         * [C-M] touch appCommon, rebuild appJs
-         * Variants: 1. code-compatible ABI breakage (change deduced return type), 2. no ABI breakage, 3. error + fix
-         */
+    @TestMetadata("generic-kmp-app-plus-lib-with-tests")
+    fun testTouchAppCommon(gradleVersion: GradleVersion) = withProject(gradleVersion) {
+        build("assemble")
 
-        //TODO KT-56963 : confirm and create issues for these source-compatible changes
-        //utilKtPath.replaceFirst("fun multiplyByTwo(n: Int): Int", "fun <T> multiplyByTwo(n: T): T") - breaks native
-        //utilKtPath.replaceFirst("fun multiplyByTwo(n: Int): Int", "fun multiplyByTwo(n: Int, unused: Int = 42): Int") - breaks js
+        val utilPath = resolvePath("app", "commonMain", "UsedInAppPlatform.kt")
+
+        multiStepCheckIncrementalBuilds(
+            incrementalPath = utilPath,
+            steps = listOf(
+                "1_changeReturnType",
+                "2_addUnusedParameter"
+                // test changes in a different order for robustness
+            ),
+            tasksExpectedToExecuteOnEachStep = setOf(
+                ":app:compileCommonMainKotlinMetadata",
+                ":app:compileKotlinJvm",
+                ":app:compileKotlinJs",
+                ":app:compileKotlinNative"
+            ),
+            afterEachStep = {
+                assertIncrementalCompilation(
+                    listOf(
+                        utilPath,
+                        resolvePath("app", "jsMain", "DependsOnAppCommon.kt"),
+                        resolvePath("app", "jvmMain", "DependsOnAppCommon.kt")
+                    ).relativizeTo(projectPath)
+                )
+            }
+        )
     }
 
+
+    /**
+     * Platform changes in a non-dependency shouldn't affect anything else
+     */
     @DisplayName("Verify IC builds on change in app/platformMain")
     @GradleTest
-    fun testTouchAppPlatform(gradleVersion: GradleVersion) {
-        /**
-         * [C-M] touch appJs, rebuild appJs
-         * Variants: 1. code-compatible ABI breakage (change deduced return type), 2. no ABI breakage, 3. error + fix
-         */
+    @TestMetadata("generic-kmp-app-plus-lib-with-tests")
+    fun testTouchAppPlatform(gradleVersion: GradleVersion) = withProject(gradleVersion) {
+        build("assemble")
 
+        /**
+         * Step 1 - jvm
+         */
+        val changedJvmSource = resolvePath("app", "jvmMain", "UnusedJvm.kt")
+            .replaceWithVersion("addParent")
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(":app:compileKotlinJvm")
+        ) {
+            assertCompiledKotlinSources(listOf(changedJvmSource).relativizeTo(projectPath), output)
+        }
+
+        /**
+         * Step 2 - js
+         */
+        val changedJsSource = resolvePath("app", "jsMain", "UnusedJs.kt")
+            .replaceWithVersion("addParent")
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(":app:compileKotlinJs")
+        ) {
+            assertIncrementalCompilation(listOf(changedJsSource).relativizeTo(projectPath))
+        }
+
+        /**
+         * Step 3 - native
+         */
+        resolvePath("app", "nativeMain", "UnusedNative.kt")
+            .replaceWithVersion("addParent")
+        checkIncrementalBuild(
+            tasksExpectedToExecute = setOf(":app:compileKotlinNative")
+        )
     }
 }
 

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

@@ -0,0 +1,29 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.gradle.testbase
+
+import org.jetbrains.kotlin.gradle.testbase.TransformationsGeneratorState.changeCounter
+import java.nio.file.Path
+import java.util.concurrent.atomic.AtomicInteger
+import kotlin.io.path.appendText
+
+
+fun Path.addPrivateVal(): Path {
+    appendText("\nprivate val integerValue${changeCounter.incrementAndGet()} = 24\n")
+    return this
+}
+
+fun Path.addPublicVal(): Path {
+    appendText("\nval integerValue${changeCounter.incrementAndGet()} = 25\n")
+    return this
+}
+
+/**
+ * Ensures that generated names are unique.
+ */
+private object TransformationsGeneratorState {
+    val changeCounter = AtomicInteger(0)
+}

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

@@ -35,7 +35,12 @@ fun BuildResult.assertTasksExecuted(vararg tasks: String) {
     tasks.forEach { task ->
         assert(task(task)?.outcome == TaskOutcome.SUCCESS) {
             printBuildOutput()
-            "Task $task didn't have 'SUCCESS' state: ${task(task)?.outcome}"
+            """
+            Task $task didn't have 'SUCCESS' state: ${task(task)?.outcome}
+
+            Actual task states:
+            ${getActualTasksAsString()}
+            """.trimIndent()
         }
     }
 }
@@ -92,7 +97,12 @@ fun BuildResult.assertTasksUpToDate(vararg tasks: String) {
     tasks.forEach { task ->
         assert(task(task)?.outcome == TaskOutcome.UP_TO_DATE) {
             printBuildOutput()
-            "Task $task didn't have 'UP-TO-DATE' state: ${task(task)?.outcome}"
+            """
+            Task $task didn't have 'UP-TO-DATE' state: ${task(task)?.outcome}
+
+            Actual task states:
+            ${getActualTasksAsString()}
+            """.trimIndent()
         }
     }
 }
@@ -204,6 +214,13 @@ fun BuildResult.assertTasksInBuildOutput(
     }
 }
 
+/**
+ * Returns printable list of tasks that actually executed.
+ */
+private fun BuildResult.getActualTasksAsString(): String {
+    return tasks.joinToString("\n") { "${it.path} - ${it.outcome}" }
+}
+
 /**
  * Method parses the output of a 'tasks --all' build
  * and returns a list of all the tasks mentioned in it.

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

@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.gradle.util
 import org.jetbrains.kotlin.gradle.testbase.createTempDirDeleteOnExit
 import java.io.File
 import java.nio.file.Path
+import kotlin.io.path.copyTo
 import kotlin.io.path.readText
 import kotlin.io.path.writeText
 
@@ -116,3 +117,9 @@ fun File.replaceText(regex: Regex, replacement: String) {
 fun Path.replaceFirst(oldValue: String, newValue: String) {
     writeText(readText().replaceFirst(oldValue, newValue))
 }
+
+fun Path.replaceWithVersion(versionSuffix: String): Path {
+    val otherVersion = resolveSibling("$fileName.$versionSuffix")
+    otherVersion.copyTo(this, overwrite = true)
+    return this
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/expect-actual-fun-or-class-ic/src/commonMain/kotlin/ExpectFunFoo.kt

@@ -1,3 +1,3 @@
 expect fun foo(): Any
 
-fun fooImpl() = secret
+fun fooImpl() = commonMainValue

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/expect-actual-fun-or-class-ic/src/commonMain/kotlin/Unused.kt

@@ -1 +0,0 @@
-val secret = 1

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/expect-actual-fun-or-class-ic/src/commonMain/kotlin/UsedInFileWithExpectFun.kt

@@ -0,0 +1 @@
+val commonMainValue = 1

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/expect-actual-fun-or-class-ic/src/commonMain/kotlin/UsedInFileWithExpectFun.kt.sourceCompatibleAbiChange

@@ -0,0 +1 @@
+val commonMainValue = "it's a string now"

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/app/src/commonMain/kotlin/Unused.kt

@@ -1,3 +1,3 @@
-class AppCommonUnusedClass {
+open class AppCommonUnusedClass {
     fun bar() = 234
 }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/app/src/commonMain/kotlin/UsedInAppPlatform.kt

@@ -0,0 +1 @@
+fun appCommonFunForAppPlatform() = "Yes"

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/app/src/commonMain/kotlin/UsedInAppPlatform.kt.1_changeReturnType

@@ -0,0 +1 @@
+fun appCommonFunForAppPlatform() = 90

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/app/src/commonMain/kotlin/UsedInAppPlatform.kt.2_addUnusedParameter

@@ -0,0 +1 @@
+fun appCommonFunForAppPlatform(delta: Double = 1.0) = 90

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/app/src/commonTest/kotlin/TestDependsOnAppCommon.kt

@@ -1,10 +0,0 @@
-import kotlin.test.Test
-import kotlin.test.assertEquals
-
-class AppCommonTest {
-
-    @Test
-    fun sayYesSaysYes() {
-        assertEquals("Yes", appCommonFunForAppPlatformAndAppCommonTest())
-    }
-}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/app/src/commonTest/kotlin/TestNoDependencies.kt

@@ -0,0 +1,10 @@
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class AppCommonTest {
+
+    @Test
+    fun threeIsThree() {
+        assertEquals(3, 3)
+    }
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/app/src/jsMain/kotlin/DependsOnAppCommon.kt

@@ -1,3 +1,3 @@
 class AppJsUnusedClassWithDependencies {
-    val line = appCommonFunForAppPlatformAndAppCommonTest()
+    val line = appCommonFunForAppPlatform()
 }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/app/src/jsMain/kotlin/UnusedJs.kt.addParent

@@ -0,0 +1,3 @@
+class AppJsUnusedClass : AppCommonUnusedClass() {
+    fun foo() = 234
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/app/src/jvmMain/kotlin/DependsOnAppCommon.kt

@@ -1,3 +1,3 @@
 class AppJvmUnusedClassWithDependencies {
-    val line = appCommonFunForAppPlatformAndAppCommonTest()
+    val line = appCommonFunForAppPlatform()
 }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/app/src/jvmMain/kotlin/UnusedJvm.kt.addParent

@@ -0,0 +1,3 @@
+class AppJvmUnusedClass : AppCommonUnusedClass() {
+    fun doBar() = 2
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/app/src/nativeMain/kotlin/DependsOnAppCommon.kt

@@ -1,3 +1,3 @@
 class AppNativeUnusedClassWithDependencies {
-    val line = appCommonFunForAppPlatformAndAppCommonTest()
+    val line = appCommonFunForAppPlatform()
 }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/app/src/nativeMain/kotlin/UnusedNative.kt.addParent

@@ -0,0 +1,3 @@
+class AppNativeUnusedClass : AppCommonUnusedClass() {
+    fun queueSomething() = Unit
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/lib/src/commonMain/kotlin/UsedInAppCommon.kt.1_addUnusedParameter

@@ -0,0 +1 @@
+fun libCommonFunForAppCommon(unused: Any? = null) = Double.NaN

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/lib/src/commonMain/kotlin/UsedInAppCommon.kt.2_changeReturnType

@@ -0,0 +1 @@
+fun libCommonFunForAppCommon(unused: Any? = null): String? = null

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/lib/src/commonMain/kotlin/UsedInAppPlatform.kt.1_addNewPublicApi

@@ -0,0 +1,6 @@
+open class LibCommonClassForAppPlatform(
+    val length: Int,
+    val builder: String,
+) {
+    val introduceNewPublicApi = "Yes, please"
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/lib/src/jsMain/kotlin/UsedInAppJsAndLibTests.kt.1_addUnusedParameter

@@ -0,0 +1 @@
+fun libJsPlatformUtil(unused: Boolean = true): Int = 0

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/lib/src/jsMain/kotlin/UsedInAppJsAndLibTests.kt.2_changeReturnType

@@ -0,0 +1 @@
+fun libJsPlatformUtil(unused: Boolean = true): Double = 20.0

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/lib/src/jsTest/kotlin/TestDependsOnCommonMainAndPlatformMain.kt

@@ -5,7 +5,7 @@ class LibJsTest {
 
     @Test
     fun jsUtilReturns0() {
-        assertEquals(0, libJsPlatformUtil())
+        assertEquals(0, libJsPlatformUtil().toInt())
     }
 
     @Test

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/lib/src/jvmMain/kotlin/UsedInAppJvmAndLibTests.kt.1_addUnusedParameter

@@ -0,0 +1 @@
+fun libJvmPlatformUtil(unused: Boolean = true): Int = 400

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/lib/src/jvmMain/kotlin/UsedInAppJvmAndLibTests.kt.2_changeReturnType

@@ -0,0 +1 @@
+fun libJvmPlatformUtil(unused: Boolean = true): Double = 20.0

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/lib/src/jvmTest/kotlin/TestDependsOnCommonMainAndPlatformMain.kt

@@ -5,7 +5,7 @@ class LibJvmTest {
 
     @Test
     fun jvmUtilReturns400() {
-        assertEquals(400, libJvmPlatformUtil())
+        assertEquals(400, libJvmPlatformUtil().toInt())
     }
 
     @Test

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/lib/src/nativeMain/kotlin/UsedInAppNativeAndLibTests.kt.1_addUnusedParameter

@@ -0,0 +1 @@
+fun libNativePlatformUtil(unused: Boolean = true): Int = 800

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/lib/src/nativeMain/kotlin/UsedInAppNativeAndLibTests.kt.2_changeReturnType

@@ -0,0 +1 @@
+fun libNativePlatformUtil(unused: Boolean = true): Double = 20.0

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/generic-kmp-app-plus-lib-with-tests/lib/src/nativeTest/kotlin/TestDependsOnCommonMainAndPlatformMain.kt

@@ -5,7 +5,7 @@ class LibNativeTest {
 
     @Test
     fun nativeUtilReturns800() {
-        assertEquals(800, libNativePlatformUtil())
+        assertEquals(800, libNativePlatformUtil().toInt())
     }
 
     @Test