FIR: add test which checks that we do not access lazy bodies & lazy expressions till contract phase

compiler/tests-common/tests/org/jetbrains/kotlin/fir/AbstractFirBaseDiagnosticsTest.kt

@@ -24,6 +24,7 @@ import org.jetbrains.kotlin.diagnostics.PsiDiagnosticUtils
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirDiagnostic
 import org.jetbrains.kotlin.fir.analysis.diagnostics.FirPsiDiagnostic
 import org.jetbrains.kotlin.fir.builder.RawFirBuilder
+import org.jetbrains.kotlin.fir.builder.RawFirBuilderMode
 import org.jetbrains.kotlin.fir.declarations.FirFile
 import org.jetbrains.kotlin.fir.extensions.BunchOfRegisteredExtensions
 import org.jetbrains.kotlin.fir.java.FirProjectSessionProvider
@@ -56,6 +57,9 @@ abstract class AbstractFirBaseDiagnosticsTest : BaseDiagnosticsTest() {
     protected open val useLightTree: Boolean
         get() = false
 
+    protected open val useLazyBodiesModeForRawFir: Boolean
+        get() = false
+
     override fun setupEnvironment(environment: KotlinCoreEnvironment) {
         PsiElementFinder.EP.getPoint(environment.project).unregisterExtension(JavaElementFinder::class.java)
     }
@@ -118,7 +122,11 @@ abstract class AbstractFirBaseDiagnosticsTest : BaseDiagnosticsTest() {
                 firFile
             }
         } else {
-            val firBuilder = RawFirBuilder(session, firProvider.kotlinScopeProvider)
+            val firBuilder = RawFirBuilder(
+                session,
+                firProvider.kotlinScopeProvider,
+                RawFirBuilderMode.lazyBodies(useLazyBodiesModeForRawFir)
+            )
             ktFiles.mapTo(firFiles) {
                 val firFile = firBuilder.buildFirFile(it)
                 firProvider.recordFile(firFile)

compiler/tests-common/tests/org/jetbrains/kotlin/fir/AbstractLazyBodyIsNotTouchedTilContractsPhaseTest.kt

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2010-2020 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.fir
+
+import org.jetbrains.kotlin.fir.declarations.FirFile
+import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
+import org.jetbrains.kotlin.fir.resolve.ScopeSession
+import org.jetbrains.kotlin.fir.resolve.transformers.createCompilerProcessorByPhase
+import java.io.File
+
+abstract class AbstractLazyBodyIsNotTouchedTilContractsPhaseTest : AbstractFirBaseDiagnosticsTest() {
+    override val useLazyBodiesModeForRawFir: Boolean get() = true
+
+    override fun runAnalysis(testDataFile: File, testFiles: List<TestFile>, firFilesPerSession: Map<FirSession, List<FirFile>>) {
+        val phases = FirResolvePhase.values().filter { phase -> phase != FirResolvePhase.RAW_FIR && phase < FirResolvePhase.CONTRACTS }
+        for ((session, firFiles) in firFilesPerSession) {
+            val scopeSession = ScopeSession()
+            /*
+             Test that we are not touching lazy bodies & lazy expressions during phases < CONTRACTS
+             If we try to access them, the exception will be thrown and test will fail
+             */
+            doFirResolveTestBench(
+                firFiles,
+                phases.map { it.createCompilerProcessorByPhase(session, scopeSession) },
+                gc = false
+            )
+        }
+    }
+}

compiler/tests/org/jetbrains/kotlin/generators/tests/GenerateCompilerTests.kt

@@ -610,6 +610,11 @@ fun main(args: Array<String>) {
             testClass<AbstractFirDiagnosticsWithLightTreeTest> {
                 model("resolve", pattern = KT_WITHOUT_DOTS_IN_NAME)
             }
+
+            testClass<AbstractLazyBodyIsNotTouchedTilContractsPhaseTest> {
+                model("resolve", pattern = KT_WITHOUT_DOTS_IN_NAME)
+            }
+
         }
 
         testGroup("compiler/fir/analysis-tests/tests", "compiler/fir/analysis-tests/testData") {