Kotlinp: add "test can be unmuted" error to K2 tests

libraries/tools/kotlinp/test/org/jetbrains/kotlin/kotlinp/test/AbstractKotlinpTest.kt

@@ -12,7 +12,7 @@ abstract class AbstractKotlinpTest : TestCaseWithTmpdir() {
     abstract fun useK2(): Boolean
 
     protected fun doTest(fileName: String) {
-        compileAndPrintAllFiles(
+        compareAllFiles(
             File(fileName),
             testRootDisposable,
             tmpdir,

libraries/tools/kotlinp/test/org/jetbrains/kotlin/kotlinp/test/KotlinpCompilerTestDataTest.kt

@@ -25,7 +25,7 @@ class KotlinpCompilerTestDataTest(private val file: File) {
 
         val disposable = TestDisposable()
         try {
-            compileAndPrintAllFiles(file, disposable, tmpdir, compareWithTxt = false, readWriteAndCompare = true, useK2 = false)
+            compareAllFiles(file, disposable, tmpdir, compareWithTxt = false, readWriteAndCompare = true, useK2 = false)
         } finally {
             Disposer.dispose(disposable)
         }

libraries/tools/kotlinp/test/org/jetbrains/kotlin/kotlinp/test/KotlinpTestUtils.kt

@@ -14,7 +14,8 @@ import org.jetbrains.kotlin.checkers.setupLanguageVersionSettingsForCompilerTest
 import org.jetbrains.kotlin.cli.jvm.compiler.EnvironmentConfigFiles
 import org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment
 import org.jetbrains.kotlin.codegen.GenerationUtils
-import org.jetbrains.kotlin.config.*
+import org.jetbrains.kotlin.config.CommonConfigurationKeys
+import org.jetbrains.kotlin.config.JVMConfigurationKeys
 import org.jetbrains.kotlin.jvm.compiler.AbstractLoadJavaTest
 import org.jetbrains.kotlin.kotlinp.Kotlinp
 import org.jetbrains.kotlin.kotlinp.KotlinpSettings
@@ -26,18 +27,36 @@ import org.jetbrains.kotlin.test.util.KtTestUtil
 import java.io.File
 import kotlin.test.fail
 
-fun compileAndPrintAllFiles(
+private const val IGNORE_K2_DIRECTIVE = "// IGNORE K2"
+
+fun compareAllFiles(
     file: File,
     disposable: Disposable,
     tmpdir: File,
     compareWithTxt: Boolean,
     readWriteAndCompare: Boolean,
-    useK2: Boolean
+    useK2: Boolean,
 ) {
-    if (useK2 && InTextDirectivesUtils.findStringWithPrefixes(file.readText(), "// IGNORE K2") != null) {
-        return
+    val isMutedForK2 = useK2 && InTextDirectivesUtils.findStringWithPrefixes(file.readText(), IGNORE_K2_DIRECTIVE) != null
+    try {
+        compileAndPrintAllFiles(file, disposable, tmpdir, compareWithTxt, readWriteAndCompare, useK2)
+    } catch (e: Throwable) {
+        if (isMutedForK2) return
+        throw e
     }
+    if (isMutedForK2) {
+        throw AssertionError("Looks like this test can be unmuted. Remove the \"$IGNORE_K2_DIRECTIVE\" directive.")
+    }
+}
 
+private fun compileAndPrintAllFiles(
+    file: File,
+    disposable: Disposable,
+    tmpdir: File,
+    compareWithTxt: Boolean,
+    readWriteAndCompare: Boolean,
+    useK2: Boolean,
+) {
     val main = StringBuilder()
     val afterVisitors = StringBuilder()
     val afterNodes = StringBuilder()