LL API: add checks to the compiler based tests to ensure ConeTypeVariableType are not leaked

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/compiler/based/AbstractCompilerBasedTest.kt

@@ -11,11 +11,11 @@ import org.jetbrains.kotlin.analysis.low.level.api.fir.api.DiagnosticCheckerFilt
 import org.jetbrains.kotlin.analysis.low.level.api.fir.api.getOrBuildFirFile
 import org.jetbrains.kotlin.analysis.low.level.api.fir.createResolveStateForNoCaching
 import org.jetbrains.kotlin.analysis.low.level.api.fir.transformers.FirLazyTransformerForIDE
-import org.jetbrains.kotlin.analysis.project.structure.*
 import org.jetbrains.kotlin.platform.jvm.JvmPlatforms
 import org.jetbrains.kotlin.test.TestConfiguration
 import org.jetbrains.kotlin.test.bind
 import org.jetbrains.kotlin.test.builders.TestConfigurationBuilder
+import org.jetbrains.kotlin.test.builders.firHandlersStep
 import org.jetbrains.kotlin.test.builders.testConfiguration
 import org.jetbrains.kotlin.test.directives.FirDiagnosticsDirectives
 import org.jetbrains.kotlin.test.directives.model.DirectivesContainer
@@ -54,6 +54,10 @@ abstract class AbstractCompilerBasedTest : AbstractKotlinCompilerTest() {
 
         useAdditionalService(::TestKtModuleProvider)
         usePreAnalysisHandlers(::ModuleRegistrarPreAnalysisHandler.bind(disposable))
+
+        firHandlersStep {
+            useHandlers(::LLDiagnosticParameterChecker)
+        }
     }
 
     open fun TestConfigurationBuilder.configureTest() {}

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/compiler/based/LLDiagnosticParameterChecker.kt

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2010-2021 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.analysis.low.level.api.fir.compiler.based
+
+import org.jetbrains.kotlin.fir.analysis.diagnostics.*
+import org.jetbrains.kotlin.fir.types.ConeKotlinType
+import org.jetbrains.kotlin.fir.types.ConeTypeVariableType
+import org.jetbrains.kotlin.fir.types.contains
+import org.jetbrains.kotlin.test.frontend.fir.FirOutputArtifact
+import org.jetbrains.kotlin.test.frontend.fir.handlers.FirAnalysisHandler
+import org.jetbrains.kotlin.test.model.TestModule
+import org.jetbrains.kotlin.test.services.TestServices
+import org.jetbrains.kotlin.test.services.assertions
+
+internal class LLDiagnosticParameterChecker(testServices: TestServices) : FirAnalysisHandler(testServices) {
+    override fun processModule(module: TestModule, info: FirOutputArtifact) {
+        val diagnostics = info.firAnalyzerFacade.runCheckers().values.flatten()
+
+        for (diagnostic in diagnostics) {
+            checkDiagnosticIsSuitableForFirIde(diagnostic)
+        }
+    }
+
+    private fun checkDiagnosticIsSuitableForFirIde(diagnostic: FirDiagnostic) {
+        val parameters = diagnostic.allParameters()
+        for (parameter in parameters) {
+            checkDiagnosticParameter(diagnostic, parameter)
+        }
+    }
+
+    private fun checkDiagnosticParameter(diagnostic: FirDiagnostic, parameter: Any?) {
+        when (parameter) {
+            is ConeKotlinType -> checkType(parameter, diagnostic)
+        }
+    }
+
+    private fun checkType(parameter: ConeKotlinType, diagnostic: FirDiagnostic) {
+        val containsTypeVariableType = parameter.contains { it is ConeTypeVariableType }
+        if (containsTypeVariableType) {
+            val rendered = FirDefaultErrorMessages.getRendererForDiagnostic(diagnostic).render(diagnostic)
+            testServices.assertions.fail {
+                "ConeTypeVariableType should not be exposed from diagnostic. But it was for ${diagnostic.factoryName} $rendered"
+            }
+        }
+    }
+
+    private fun FirDiagnostic.allParameters(): List<Any?> = when (this) {
+        is FirPsiDiagnosticWithParameters1<*> -> listOf(a)
+        is FirPsiDiagnosticWithParameters2<*, *> -> listOf(a, b)
+        is FirPsiDiagnosticWithParameters3<*, *, *> -> listOf(a, b, c)
+        is FirPsiDiagnosticWithParameters4<*, *, *, *> -> listOf(a, b, c, d)
+        is FirPsiSimpleDiagnostic -> emptyList()
+        else -> error("Unexpected diagnostic $this")
+    }
+
+    override fun processAfterAllModules(someAssertionWasFailed: Boolean) {}
+}