[HL API] Fix FE10 implementation of KtExpressionTypeProvider

analysis/analysis-api-fe10/src/org/jetbrains/kotlin/analysis/api/descriptors/components/KtFe10ExpressionTypeProvider.kt

@@ -72,8 +72,13 @@ class KtFe10ExpressionTypeProvider(
 
             if (typeReference != null) {
                 val bindingContext = analysisContext.analyze(typeReference, AnalysisMode.PARTIAL)
-                val kotlinType = bindingContext[BindingContext.TYPE, typeReference]
-                    ?: ErrorUtils.createErrorType(ErrorTypeKind.RETURN_TYPE, typeReference.text)
+                val kotlinType =
+                    if (declaration is KtParameter && declaration.isVarArg) {
+                        // we want full Array<out T> type for parity with FIR implementation
+                        bindingContext[BindingContext.VALUE_PARAMETER, declaration]?.returnType
+                    } else {
+                        bindingContext[BindingContext.TYPE, typeReference]
+                    } ?: ErrorUtils.createErrorType(ErrorTypeKind.RETURN_TYPE, typeReference.text)
 
                 return kotlinType.toKtType(analysisContext)
             }

analysis/analysis-api-fe10/tests-gen/org/jetbrains/kotlin/analysis/api/fe10/test/cases/generated/cases/components/expressionTypeProvider/Fe10IdeNormalAnalysisSourceModuleDeclarationReturnTypeTestGenerated.java

@@ -93,4 +93,10 @@ public class Fe10IdeNormalAnalysisSourceModuleDeclarationReturnTypeTestGenerated
     public void testTypeParameters() throws Exception {
         runTest("analysis/analysis-api/testData/components/expressionTypeProvider/declarationReturnType/typeParameters.kt");
     }
+
+    @Test
+    @TestMetadata("varargParam.kt")
+    public void testVarargParam() throws Exception {
+        runTest("analysis/analysis-api/testData/components/expressionTypeProvider/declarationReturnType/varargParam.kt");
+    }
 }

analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/expressionTypeProvider/FirIdeDependentAnalysisSourceModuleDeclarationReturnTypeTestGenerated.java

@@ -93,4 +93,10 @@ public class FirIdeDependentAnalysisSourceModuleDeclarationReturnTypeTestGenerat
     public void testTypeParameters() throws Exception {
         runTest("analysis/analysis-api/testData/components/expressionTypeProvider/declarationReturnType/typeParameters.kt");
     }
+
+    @Test
+    @TestMetadata("varargParam.kt")
+    public void testVarargParam() throws Exception {
+        runTest("analysis/analysis-api/testData/components/expressionTypeProvider/declarationReturnType/varargParam.kt");
+    }
 }

analysis/analysis-api-fir/tests-gen/org/jetbrains/kotlin/analysis/api/fir/test/cases/generated/cases/components/expressionTypeProvider/FirIdeNormalAnalysisSourceModuleDeclarationReturnTypeTestGenerated.java

@@ -93,4 +93,10 @@ public class FirIdeNormalAnalysisSourceModuleDeclarationReturnTypeTestGenerated
     public void testTypeParameters() throws Exception {
         runTest("analysis/analysis-api/testData/components/expressionTypeProvider/declarationReturnType/typeParameters.kt");
     }
+
+    @Test
+    @TestMetadata("varargParam.kt")
+    public void testVarargParam() throws Exception {
+        runTest("analysis/analysis-api/testData/components/expressionTypeProvider/declarationReturnType/varargParam.kt");
+    }
 }

analysis/analysis-api-standalone/tests-gen/org/jetbrains/kotlin/analysis/api/standalone/fir/test/cases/generated/cases/components/expressionTypeProvider/FirStandaloneNormalAnalysisSourceModuleDeclarationReturnTypeTestGenerated.java

@@ -93,4 +93,10 @@ public class FirStandaloneNormalAnalysisSourceModuleDeclarationReturnTypeTestGen
     public void testTypeParameters() throws Exception {
         runTest("analysis/analysis-api/testData/components/expressionTypeProvider/declarationReturnType/typeParameters.kt");
     }
+
+    @Test
+    @TestMetadata("varargParam.kt")
+    public void testVarargParam() throws Exception {
+        runTest("analysis/analysis-api/testData/components/expressionTypeProvider/declarationReturnType/varargParam.kt");
+    }
 }

analysis/analysis-api/src/org/jetbrains/kotlin/analysis/api/components/KtExpressionTypeProvider.kt

@@ -35,7 +35,11 @@ public interface KtExpressionTypeProviderMixIn : KtAnalysisSessionMixIn {
         withValidityAssertion { analysisSession.expressionTypeProvider.getKtExpressionType(this) }
 
     /**
-     * Returns the return type of the given [KtDeclaration] as [KtType]
+     * Returns the return type of the given [KtDeclaration] as [KtType].
+     *
+     * IMPORTANT: For `vararg foo: T` parameter returns full `Array<out T>` type (unlike
+     * [KtValueParameterSymbol.returnType][org.jetbrains.kotlin.analysis.api.symbols.KtValueParameterSymbol.returnType],
+     * which returns `T`).
      */
     public fun KtDeclaration.getReturnKtType(): KtType =
         withValidityAssertion { analysisSession.expressionTypeProvider.getReturnTypeForKtDeclaration(this) }

analysis/analysis-api/testData/components/expressionTypeProvider/declarationReturnType/varargParam.kt

@@ -0,0 +1,5 @@
+class Foo(vararg constructorValues: String)
+
+fun test(vararg values: String) {}
+
+fun test(vararg primitiveValues: Int) {}

analysis/analysis-api/testData/components/expressionTypeProvider/declarationReturnType/varargParam.txt

@@ -0,0 +1,7 @@
+Foo@(1,1)
+  Foo@(1,10) : Foo
+    constructorValues@(1,11) : kotlin.Array<out kotlin.String>
+test@(3,1) : kotlin.Unit
+  values@(3,10) : kotlin.Array<out kotlin.String>
+test@(5,1) : kotlin.Unit
+  primitiveValues@(5,10) : kotlin.IntArray