AA FIR: functional type for anonymous function

^KTIJ-17657 In progress

analysis/analysis-api-fe10/tests-gen/org/jetbrains/kotlin/analysis/api/fe10/test/cases/generated/cases/components/expressionTypeProvider/Fe10IdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated.java

@@ -46,6 +46,12 @@ public class Fe10IdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated exte
         KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType"), Pattern.compile("^(.+)\\.kt$"), null, true);
     }
 
+    @Test
+    @TestMetadata("anonymousFunction.kt")
+    public void testAnonymousFunction() throws Exception {
+        runTest("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/anonymousFunction.kt");
+    }
+
     @Test
     @TestMetadata("arrayElement_arrayOfNulls.kt")
     public void testArrayElement_arrayOfNulls() throws Exception {

analysis/analysis-api-fir/src/org/jetbrains/kotlin/analysis/api/fir/components/KtFirExpressionTypeProvider.kt

@@ -11,7 +11,6 @@ import org.jetbrains.kotlin.analysis.api.fir.KtFirAnalysisSession
 import org.jetbrains.kotlin.analysis.api.fir.utils.getReferencedElementType
 import org.jetbrains.kotlin.analysis.api.fir.utils.unwrap
 import org.jetbrains.kotlin.analysis.api.lifetime.KtLifetimeToken
-import org.jetbrains.kotlin.analysis.api.lifetime.withValidityAssertion
 import org.jetbrains.kotlin.analysis.api.types.KtType
 import org.jetbrains.kotlin.analysis.low.level.api.fir.api.getOrBuildFir
 import org.jetbrains.kotlin.analysis.low.level.api.fir.api.getOrBuildFirOfType
@@ -20,7 +19,6 @@ import org.jetbrains.kotlin.fir.FirLabel
 import org.jetbrains.kotlin.fir.FirPackageDirective
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.utils.isSuspend
-import org.jetbrains.kotlin.fir.declarations.utils.superConeTypes
 import org.jetbrains.kotlin.fir.expressions.*
 import org.jetbrains.kotlin.fir.psi
 import org.jetbrains.kotlin.fir.references.FirNamedReference
@@ -31,6 +29,8 @@ import org.jetbrains.kotlin.fir.symbols.impl.FirClassSymbol
 import org.jetbrains.kotlin.fir.types.*
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.contract
 
 internal class KtFirExpressionTypeProvider(
     override val analysisSession: KtFirAnalysisSession,
@@ -96,20 +96,33 @@ internal class KtFirExpressionTypeProvider(
     }
 
     override fun getReturnTypeForKtDeclaration(declaration: KtDeclaration): KtType {
-        val firDeclaration = when {
+        val firDeclaration = if (isAnonymousFunction(declaration))
-            declaration is KtNamedFunction && declaration.name == null ->
+            declaration.toFirAnonymousFunction()
-                declaration.getOrBuildFirOfType<FirAnonymousFunctionExpression>(firResolveSession).anonymousFunction
+        else
-            else ->
+            declaration.getOrBuildFirOfType<FirCallableDeclaration>(firResolveSession)
-                declaration.getOrBuildFirOfType<FirCallableDeclaration>(firResolveSession)
-        }
         return firDeclaration.returnTypeRef.coneType.asKtType()
     }
 
     override fun getFunctionalTypeForKtFunction(declaration: KtFunction): KtType {
-        val firFunction = declaration.getOrBuildFirOfType<FirFunction>(firResolveSession)
+        val firFunction = if (isAnonymousFunction(declaration))
+            declaration.toFirAnonymousFunction()
+        else
+            declaration.getOrBuildFirOfType<FirFunction>(firResolveSession)
         return firFunction.constructFunctionalType(firFunction.isSuspend).asKtType()
     }
 
+    @OptIn(ExperimentalContracts::class)
+    private fun isAnonymousFunction(ktDeclaration: KtDeclaration): Boolean {
+        contract {
+            returns(true) implies (ktDeclaration is KtNamedFunction)
+        }
+        return ktDeclaration is KtFunction && ktDeclaration.name == null
+    }
+
+    private fun KtFunction.toFirAnonymousFunction(): FirAnonymousFunction {
+        return getOrBuildFirOfType<FirAnonymousFunctionExpression>(firResolveSession).anonymousFunction
+    }
+
     override fun getExpectedType(expression: PsiElement): KtType? {
         val unwrapped = expression.unwrap()
         val expectedType = getExpectedTypeByReturnExpression(unwrapped)

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

@@ -46,6 +46,12 @@ public class FirIdeDependentAnalysisSourceModuleHLExpressionTypeTestGenerated ex
         KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType"), Pattern.compile("^(.+)\\.kt$"), null, true);
     }
 
+    @Test
+    @TestMetadata("anonymousFunction.kt")
+    public void testAnonymousFunction() throws Exception {
+        runTest("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/anonymousFunction.kt");
+    }
+
     @Test
     @TestMetadata("arrayElement_arrayOfNulls.kt")
     public void testArrayElement_arrayOfNulls() throws Exception {

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

@@ -46,6 +46,12 @@ public class FirIdeNormalAnalysisSourceModuleHLExpressionTypeTestGenerated exten
         KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType"), Pattern.compile("^(.+)\\.kt$"), null, true);
     }
 
+    @Test
+    @TestMetadata("anonymousFunction.kt")
+    public void testAnonymousFunction() throws Exception {
+        runTest("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/anonymousFunction.kt");
+    }
+
     @Test
     @TestMetadata("arrayElement_arrayOfNulls.kt")
     public void testArrayElement_arrayOfNulls() throws Exception {

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

@@ -46,6 +46,12 @@ public class FirStandaloneNormalAnalysisSourceModuleHLExpressionTypeTestGenerate
         KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType"), Pattern.compile("^(.+)\\.kt$"), null, true);
     }
 
+    @Test
+    @TestMetadata("anonymousFunction.kt")
+    public void testAnonymousFunction() throws Exception {
+        runTest("analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/anonymousFunction.kt");
+    }
+
     @Test
     @TestMetadata("arrayElement_arrayOfNulls.kt")
     public void testArrayElement_arrayOfNulls() throws Exception {

analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/anonymousFunction.kt

@@ -0,0 +1,3 @@
+fun foo() {
+    val f = <expr>fun(it: String) {}</expr>
+}

analysis/analysis-api/testData/components/expressionTypeProvider/expressionType/anonymousFunction.txt

@@ -0,0 +1,2 @@
+expression: fun(it: String) {}
+type: (kotlin.String) -> kotlin.Unit