[FIR-IDE] Hack for checking single candidate resolver in tests

idea/build.gradle.kts

@@ -187,6 +187,7 @@ dependencies {
     testRuntime(intellijPluginDep("smali"))
     testRuntime(intellijPluginDep("testng"))
 
+    testRuntime(project(":idea:idea-fir"))
     testRuntime(project(":idea:idea-frontend-fir"))
 
     if (Ide.AS36.orHigher()) {

idea/idea-completion/testData/basic/common/ConsiderExtensionType.kt

@@ -0,0 +1,20 @@
+class A
+open class B
+
+class C : B()
+interface D
+
+fun <T> T.ext1() where T : B {}
+fun B.ext2() {}
+fun A.ext3() {}
+fun <T> T.ext4() where T : B, T : D {}
+
+fun usage() {
+    val c = C()
+    c.ext<caret>
+}
+
+// EXIST: ext1
+// EXIST: ext2
+// ABSENT: ext3
+// ABSENT: ext4

idea/idea-completion/testData/basic/common/ExtensionsWithTypeParameterConstraints.kt

@@ -0,0 +1,11 @@
+fun <T : Int> T.ext1() {}
+fun <T : String> T.ext2() {}
+
+fun test() {
+    with(42) {
+        ext<caret>
+    }
+}
+
+// EXIST: ext1
+// ABSENT: ext2

idea/idea-completion/testData/basic/common/GenericCompanionExtension.kt

@@ -0,0 +1,24 @@
+class A<T1, T2> {
+    fun foo1() {}
+
+    class B<T3, T4> {
+        fun foo2() {}
+
+        fun foo3() {
+            foo<caret>
+        }
+    }
+
+    class C
+
+    companion object {
+        fun <T7, T8> B<T7, T8>.foo4() {}
+        fun C.foo5() {}
+    }
+}
+
+// ABSENT: foo1
+// EXIST: foo2
+// EXIST: foo3
+// EXIST: foo4
+// ABSENT: foo5

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/JSBasicCompletionTestGenerated.java

@@ -85,6 +85,11 @@ public class JSBasicCompletionTestGenerated extends AbstractJSBasicCompletionTes
             runTest("idea/idea-completion/testData/basic/common/ComponentFunction.kt");
         }
 
+        @TestMetadata("ConsiderExtensionType.kt")
+        public void testConsiderExtensionType() throws Exception {
+            runTest("idea/idea-completion/testData/basic/common/ConsiderExtensionType.kt");
+        }
+
         @TestMetadata("CoroutineContext.kt")
         public void testCoroutineContext() throws Exception {
             runTest("idea/idea-completion/testData/basic/common/CoroutineContext.kt");
@@ -185,6 +190,11 @@ public class JSBasicCompletionTestGenerated extends AbstractJSBasicCompletionTes
             runTest("idea/idea-completion/testData/basic/common/ExtensionWithManyTypeParamsInReceiver.kt");
         }
 
+        @TestMetadata("ExtensionsWithTypeParameterConstraints.kt")
+        public void testExtensionsWithTypeParameterConstraints() throws Exception {
+            runTest("idea/idea-completion/testData/basic/common/ExtensionsWithTypeParameterConstraints.kt");
+        }
+
         @TestMetadata("FromImports.kt")
         public void testFromImports() throws Exception {
             runTest("idea/idea-completion/testData/basic/common/FromImports.kt");
@@ -200,6 +210,11 @@ public class JSBasicCompletionTestGenerated extends AbstractJSBasicCompletionTes
             runTest("idea/idea-completion/testData/basic/common/FunctionVariableCallArgument.kt");
         }
 
+        @TestMetadata("GenericCompanionExtension.kt")
+        public void testGenericCompanionExtension() throws Exception {
+            runTest("idea/idea-completion/testData/basic/common/GenericCompanionExtension.kt");
+        }
+
         @TestMetadata("GenericExtensionFunReceiver1.kt")
         public void testGenericExtensionFunReceiver1() throws Exception {
             runTest("idea/idea-completion/testData/basic/common/GenericExtensionFunReceiver1.kt");

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/JvmBasicCompletionTestGenerated.java

@@ -85,6 +85,11 @@ public class JvmBasicCompletionTestGenerated extends AbstractJvmBasicCompletionT
             runTest("idea/idea-completion/testData/basic/common/ComponentFunction.kt");
         }
 
+        @TestMetadata("ConsiderExtensionType.kt")
+        public void testConsiderExtensionType() throws Exception {
+            runTest("idea/idea-completion/testData/basic/common/ConsiderExtensionType.kt");
+        }
+
         @TestMetadata("CoroutineContext.kt")
         public void testCoroutineContext() throws Exception {
             runTest("idea/idea-completion/testData/basic/common/CoroutineContext.kt");
@@ -185,6 +190,11 @@ public class JvmBasicCompletionTestGenerated extends AbstractJvmBasicCompletionT
             runTest("idea/idea-completion/testData/basic/common/ExtensionWithManyTypeParamsInReceiver.kt");
         }
 
+        @TestMetadata("ExtensionsWithTypeParameterConstraints.kt")
+        public void testExtensionsWithTypeParameterConstraints() throws Exception {
+            runTest("idea/idea-completion/testData/basic/common/ExtensionsWithTypeParameterConstraints.kt");
+        }
+
         @TestMetadata("FromImports.kt")
         public void testFromImports() throws Exception {
             runTest("idea/idea-completion/testData/basic/common/FromImports.kt");
@@ -200,6 +210,11 @@ public class JvmBasicCompletionTestGenerated extends AbstractJvmBasicCompletionT
             runTest("idea/idea-completion/testData/basic/common/FunctionVariableCallArgument.kt");
         }
 
+        @TestMetadata("GenericCompanionExtension.kt")
+        public void testGenericCompanionExtension() throws Exception {
+            runTest("idea/idea-completion/testData/basic/common/GenericCompanionExtension.kt");
+        }
+
         @TestMetadata("GenericExtensionFunReceiver1.kt")
         public void testGenericExtensionFunReceiver1() throws Exception {
             runTest("idea/idea-completion/testData/basic/common/GenericExtensionFunReceiver1.kt");

idea/idea-frontend-api/src/org/jetbrains/kotlin/idea/frontend/api/KtAnalysisSession.kt

@@ -118,4 +118,11 @@ abstract class KtAnalysisSession(override val token: ValidityToken) : ValidityTo
         check(this is KtSymbolBasedReference) { "To get reference symbol the one should be KtSymbolBasedReference but was ${this::class}" }
         return resolveToSymbols().singleOrNull()
     }
+
+    abstract fun resolveAndCheckReceivers(
+        firSymbolForCandidate: KtCallableSymbol,
+        originalFile: KtFile,
+        nameExpression: KtSimpleNameExpression,
+        possibleReceiver: KtExpression?,
+    ): Boolean
 }

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/KtFirAnalysisSession.kt

@@ -5,6 +5,9 @@
 
 package org.jetbrains.kotlin.idea.frontend.api.fir
 
+import com.jetbrains.rd.util.getOrCreate
+import org.jetbrains.kotlin.fir.declarations.*
+import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.resolve.firSymbolProvider
 import org.jetbrains.kotlin.idea.fir.low.level.api.FirModuleResolveState
 import org.jetbrains.kotlin.idea.fir.low.level.api.LowLevelFirApiFacade
@@ -17,10 +20,20 @@ import org.jetbrains.kotlin.idea.frontend.api.components.KtDiagnosticProvider
 import org.jetbrains.kotlin.idea.frontend.api.components.KtSmartCastProvider
 import org.jetbrains.kotlin.idea.frontend.api.components.KtTypeProvider
 import org.jetbrains.kotlin.idea.frontend.api.fir.components.*
+import org.jetbrains.kotlin.idea.fir.*
+import org.jetbrains.kotlin.idea.fir.low.level.api.resolver.SingleCandidateResolver
+import org.jetbrains.kotlin.idea.fir.low.level.api.resolver.SingleCandidateResolutionMode
+import org.jetbrains.kotlin.idea.fir.low.level.api.resolver.ResolutionParameters
+import org.jetbrains.kotlin.idea.frontend.api.fir.symbols.KtFirFunctionSymbol
 import org.jetbrains.kotlin.idea.frontend.api.fir.symbols.KtFirSymbolProvider
 import org.jetbrains.kotlin.idea.frontend.api.fir.utils.threadLocal
 import org.jetbrains.kotlin.idea.frontend.api.symbols.KtSymbolProvider
 import org.jetbrains.kotlin.psi.KtElement
+import org.jetbrains.kotlin.idea.frontend.api.symbols.*
+import org.jetbrains.kotlin.idea.util.getElementTextInContext
+import org.jetbrains.kotlin.psi.*
+import org.jetbrains.kotlin.psi.psiUtil.getNonStrictParentOfType
+import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 
 internal class KtFirAnalysisSession
 private constructor(
@@ -58,6 +71,53 @@ private constructor(
         )
     }
 
+    private val completionContextCache = HashMap<Pair<FirFile, KtNamedFunction>, LowLevelFirApiFacade.FirCompletionContext>()
+
+    // Temporary kludge to check single candidate resolver in tests
+    override fun resolveAndCheckReceivers(
+        firSymbolForCandidate: KtCallableSymbol,
+        originalFile: KtFile,
+        nameExpression: KtSimpleNameExpression,
+        possibleReceiver: KtExpression?,
+    ): Boolean {
+        firSymbolForCandidate.safeAs<KtFirFunctionSymbol>()?.firRef?.withFir { firFunction ->
+            val file = originalFile.getOrBuildFirOfType<FirFile>(firResolveState)
+            val explicitReceiverExpression = possibleReceiver?.getOrBuildFirOfType<FirExpression>(firResolveState)
+            val resolver = SingleCandidateResolver(firResolveState.firIdeSourcesSession, file)
+            val enclosingFunction = nameExpression.getNonStrictParentOfType<KtNamedFunction>()
+                ?: error("Cannot find enclosing function for ${nameExpression.getElementTextInContext()}")
+
+            val completionContext = completionContextCache.getOrCreate(file to enclosingFunction) {
+                LowLevelFirApiFacade.buildCompletionContextForFunction(
+                    file,
+                    enclosingFunction,
+                    enclosingFunction,
+                    state = firResolveState
+                )
+            }
+
+            val towerDataContext = completionContext.getTowerDataContext(nameExpression)
+
+            val implicitReceivers = sequence {
+                yield(null)
+                yieldAll(towerDataContext.implicitReceiverStack)
+            }
+            for (implicitReceiverValue in implicitReceivers) {
+                val resolutionParameters = ResolutionParameters(
+                    singleCandidateResolutionMode = SingleCandidateResolutionMode.CHECK_EXTENSION_FOR_COMPLETION,
+                    callableSymbol = firFunction.symbol,
+                    implicitReceiver = implicitReceiverValue,
+                    explicitReceiver = explicitReceiverExpression
+                )
+                resolver.resolveSingleCandidate(resolutionParameters)?.let {
+                    // not null if resolved and completed successfully
+                    return true
+                }
+            }
+        }
+        return false
+    }
+
     companion object {
         @Deprecated("Please use org.jetbrains.kotlin.idea.frontend.api.KtAnalysisSessionProviderKt.analyze")
         internal fun createForElement(element: KtElement): KtFirAnalysisSession {

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/components/KtFirScopeProvider.kt

@@ -13,10 +13,7 @@ import org.jetbrains.kotlin.fir.resolve.ScopeSession
 import org.jetbrains.kotlin.fir.resolve.scope
 import org.jetbrains.kotlin.fir.scopes.FirContainingNamesAwareScope
 import org.jetbrains.kotlin.fir.scopes.FirScope
-import org.jetbrains.kotlin.fir.scopes.impl.FirAbstractSimpleImportingScope
+import org.jetbrains.kotlin.fir.scopes.impl.*
-import org.jetbrains.kotlin.fir.scopes.impl.FirAbstractStarImportingScope
-import org.jetbrains.kotlin.fir.scopes.impl.FirPackageMemberScope
-import org.jetbrains.kotlin.fir.scopes.impl.declaredMemberScope
 import org.jetbrains.kotlin.fir.scopes.unsubstitutedScope
 import org.jetbrains.kotlin.idea.fir.getOrBuildFirOfType
 import org.jetbrains.kotlin.idea.fir.low.level.api.FirModuleResolveState
@@ -155,6 +152,7 @@ internal class KtFirScopeProvider(
             is FirAbstractStarImportingScope -> KtFirStarImportingScope(firScope, builder, project, token)
             is FirPackageMemberScope -> KtFirPackageScope(firScope, project, builder, token)
             is FirContainingNamesAwareScope -> KtFirDelegatingScopeImpl(firScope, builder, token)
+            is FirMemberTypeParameterScope -> KtFirMemberTypeParameterStubbingScope(firScope, token)
             else -> TODO(firScope::class.toString())
         }
     }

idea/idea-frontend-fir/src/org/jetbrains/kotlin/idea/frontend/api/fir/scopes/KtFirMemberTypeParameterStubbingScope.kt

@@ -0,0 +1,36 @@
+/*
+ * 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.idea.frontend.api.fir.scopes
+
+import org.jetbrains.kotlin.fir.scopes.impl.FirMemberTypeParameterScope
+import org.jetbrains.kotlin.idea.frontend.api.ValidityToken
+import org.jetbrains.kotlin.idea.frontend.api.scopes.KtScope
+import org.jetbrains.kotlin.idea.frontend.api.symbols.KtCallableSymbol
+import org.jetbrains.kotlin.idea.frontend.api.symbols.KtClassLikeSymbol
+import org.jetbrains.kotlin.name.Name
+
+// Does nothing, it is used to close the hole in KtFirScopeProvider
+// TODO: check if this scope should provide something useful
+class KtFirMemberTypeParameterStubbingScope(
+    val firMemberTypeParameterScope: FirMemberTypeParameterScope,
+    override val token: ValidityToken,
+) : KtScope {
+    override fun getCallableNames(): Set<Name> {
+        return emptySet()
+    }
+
+    override fun getClassLikeSymbolNames(): Set<Name> {
+        return emptySet()
+    }
+
+    override fun getCallableSymbols(): Sequence<KtCallableSymbol> {
+        return emptySequence()
+    }
+
+    override fun getClassClassLikeSymbols(): Sequence<KtClassLikeSymbol> {
+        return emptySequence()
+    }
+}