diff --git a/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/util/diagnosticUtils.kt b/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/util/diagnosticUtils.kt
new file mode 100644
index 00000000000..541babe6f40
--- /dev/null
+++ b/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/util/diagnosticUtils.kt
@@ -0,0 +1,74 @@
+/*
+ * 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.util
+
+import org.gradle.api.Project
+import org.jetbrains.kotlin.gradle.plugin.diagnostics.kotlinToolingDiagnosticsCollector
+import org.jetbrains.kotlin.test.KotlinTestUtils
+import org.jetbrains.kotlin.gradle.plugin.diagnostics.ToolingDiagnostic
+import java.io.File
+import java.nio.file.Path
+import kotlin.test.assertTrue
+
+internal fun checkDiagnosticsWithMppProject(projectName: String, projectConfiguration: Project.() -> Unit) {
+    val project = buildProjectWithMPP(projectBuilder = { withName(projectName) })
+    project.setMultiplatformAndroidSourceSetLayoutVersion(2)
+    project.projectConfiguration()
+    project.evaluate()
+    project.checkDiagnostics(projectName)
+}
+
+
+/**
+ * [compactRendering] == true will omit projects with no diagnostics from the report, as well as
+ * name of the project if it's a single one with diagnostics (useful for small one-project tests)
+ */
+internal fun Project.checkDiagnostics(testDataName: String, compactRendering: Boolean = true) {
+    val diagnosticsPerProject = rootProject.allprojects.mapNotNull {
+        val diagnostics = it.kotlinToolingDiagnosticsCollector.getDiagnosticsForProject(it)
+        if (diagnostics.isEmpty() && compactRendering)
+            null
+        else
+            it.name to diagnostics
+    }.toMap()
+    val expectedDiagnostics = expectedDiagnosticsFile(testDataName)
+
+    if (diagnosticsPerProject.all { (_, diagnostics) -> diagnostics.isEmpty() }) {
+        if (expectedDiagnostics.exists())
+            error("Expected to have some diagnostics in file://${expectedDiagnostics.canonicalPath}, but none were actually reported")
+        else
+            return // do not create empty file
+    }
+
+    val actualRenderedText = if (diagnosticsPerProject.size == 1 && compactRendering) {
+        diagnosticsPerProject.entries.single().value.render()
+    } else {
+        diagnosticsPerProject
+            .entries
+            .joinToString(separator = "\n\n") { (projectName, diagnostics) ->
+                val nameSanitized = if (projectName == "test") "<root>" else projectName
+                "PROJECT: $nameSanitized\n" + diagnostics.render()
+            }
+    }
+
+    val sanitizedTest = actualRenderedText.replace(File.separator, "/")
+
+    KotlinTestUtils.assertEqualsToFile(expectedDiagnostics, sanitizedTest)
+}
+
+internal fun Project.assertNoDiagnostics() {
+    val actualDiagnostics = kotlinToolingDiagnosticsCollector.getDiagnosticsForProject(this)
+    assertTrue(
+        actualDiagnostics.isEmpty(), "Expected to have no diagnostics, but some were reported:\n ${actualDiagnostics.render()}"
+    )
+}
+
+private fun Collection<ToolingDiagnostic>.render(): String = joinToString(separator = "\n----\n")
+
+private val expectedDiagnosticsRoot: Path
+    get() = resourcesRoot.resolve("expectedDiagnostics")
+
+private fun expectedDiagnosticsFile(projectName: String): File = expectedDiagnosticsRoot.resolve("$projectName.txt").toFile()
diff --git a/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/util/fileUtils.kt b/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/util/fileUtils.kt
index 381143be602..088565278fa 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/util/fileUtils.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/util/fileUtils.kt
@@ -7,5 +7,10 @@ package org.jetbrains.kotlin.gradle.util
 
 import org.gradle.api.Project
 import java.io.File
+import java.nio.file.Path
+import java.nio.file.Paths
 
-fun Set<File>.relativeTo(project: Project): Set<File> = map { it.relativeTo(project.projectDir) }.toSet()
\ No newline at end of file
+fun Set<File>.relativeTo(project: Project): Set<File> = map { it.relativeTo(project.projectDir) }.toSet()
+
+val resourcesRoot: Path
+    get() = Paths.get("src", "functionalTest", "resources")
diff --git a/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/util/mppProjectConfigurationUtils.kt b/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/util/mppProjectConfigurationUtils.kt
new file mode 100644
index 00000000000..775594f67d9
--- /dev/null
+++ b/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/util/mppProjectConfigurationUtils.kt
@@ -0,0 +1,35 @@
+/*
+ * 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.util
+
+import org.jetbrains.kotlin.gradle.dsl.KotlinMultiplatformExtension
+import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSet
+
+val KotlinMultiplatformExtension.commonMain: KotlinSourceSet
+    get() = sourceSets.getByName("commonMain")
+
+val KotlinMultiplatformExtension.commonTest: KotlinSourceSet
+    get() = sourceSets.getByName("commonTest")
+
+val KotlinMultiplatformExtension.jvmMain: KotlinSourceSet
+    get() = sourceSets.getByName("jvmMain")
+
+val KotlinMultiplatformExtension.jvmTest: KotlinSourceSet
+    get() = sourceSets.getByName("jvmTest")
+
+val KotlinMultiplatformExtension.androidMain: KotlinSourceSet
+    get() = sourceSets.getByName("androidMain")
+
+val KotlinMultiplatformExtension.androidTest: KotlinSourceSet
+    get() = sourceSets.getByName("androidTest")
+
+val KotlinMultiplatformExtension.iosMain: KotlinSourceSet
+    get() = sourceSets.getByName("iosMain")
+
+val KotlinMultiplatformExtension.iosTest: KotlinSourceSet
+    get() = sourceSets.getByName("iosTest")
+
+operator fun KotlinSourceSet.invoke(config: KotlinSourceSet.() -> Unit) = config()