Add some new tests on functions and extension functions

compiler/testData/codegen/box/functions/invoke/castFunctionToExtension.kt

@@ -0,0 +1,11 @@
+fun box(): String {
+    val f = fun (s: String): String = s
+    val g = f as String.() -> String
+    if ("OK".g() != "OK") return "Fail 1"
+
+    val h = fun String.(): String = this
+    val i = h as (String) -> String
+    if (i("OK") != "OK") return "Fail 2"
+
+    return "OK"
+}

compiler/testData/codegen/boxWithJava/reflection/functionReferenceErasedToKFunction/J.java

@@ -0,0 +1,10 @@
+import kotlin.jvm.functions.Function2;
+import kotlin.reflect.KMemberFunction;
+
+public class J {
+    public static String go() {
+        KMemberFunction<K, String> fun = K.Companion.getRef();
+        Object result = ((Function2) fun).invoke(new K(), "KO");
+        return (String) result;
+    }
+}

compiler/testData/codegen/boxWithJava/reflection/functionReferenceErasedToKFunction/K.kt

@@ -0,0 +1,13 @@
+class K {
+    fun reverse(s: String): String {
+        return s.reverse()
+    }
+
+    companion object {
+        fun getRef() = K::reverse
+    }
+}
+
+fun box(): String {
+    return J.go()
+}

compiler/testData/codegen/boxWithStdlib/callableReference/function/listOfStringsMapLength.kt

@@ -0,0 +1,2 @@
+fun box(): String =
+        if (listOf("abc", "de", "f").map(String::length) == listOf(3, 2, 1)) "OK" else "Fail"

compiler/testData/diagnostics/tests/annotations/extensionFunctionType.kt

@@ -0,0 +1,10 @@
+// This test checks that annotations on extension function types are preserved. See the corresponding .txt file
+
+annotation class ann
+
+interface Some {
+    fun f1(): String.() -> Int
+    fun f2(): @extension String.() -> Int
+    fun f3(): @ann String.() -> Int
+    fun f4(): @extension @ann String.() -> Int
+}

compiler/testData/diagnostics/tests/annotations/extensionFunctionType.txt

@@ -0,0 +1,18 @@
+package
+
+internal interface Some {
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    internal abstract fun f1(): kotlin.String.() -> kotlin.Int
+    internal abstract fun f2(): @[kotlin.extension()] kotlin.String.() -> kotlin.Int
+    internal abstract fun f3(): @[ann()] kotlin.String.() -> kotlin.Int
+    internal abstract fun f4(): @[kotlin.extension() ann()] kotlin.String.() -> kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}
+
+internal final annotation class ann : kotlin.Annotation {
+    public constructor ann()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+}

compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java

@@ -711,6 +711,12 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
                 doTest(fileName);
             }
 
+            @TestMetadata("extensionFunctionType.kt")
+            public void testExtensionFunctionType() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/annotations/extensionFunctionType.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("forParameterAnnotationResolve.kt")
             public void testForParameterAnnotationResolve() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/annotations/forParameterAnnotationResolve.kt");

compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxCodegenTestGenerated.java

@@ -3894,6 +3894,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/box/functions/invoke"), Pattern.compile("^(.+)\\.kt$"), true);
             }
 
+            @TestMetadata("castFunctionToExtension.kt")
+            public void testCastFunctionToExtension() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/functions/invoke/castFunctionToExtension.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("extensionInvokeOnExpr.kt")
             public void testExtensionInvokeOnExpr() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/box/functions/invoke/extensionInvokeOnExpr.kt");

compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithJavaCodegenTestGenerated.java

@@ -229,6 +229,12 @@ public class BlackBoxWithJavaCodegenTestGenerated extends AbstractBlackBoxCodege
             JetTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("compiler/testData/codegen/boxWithJava/reflection"), Pattern.compile("^([^\\.]+)$"), true);
         }
 
+        @TestMetadata("functionReferenceErasedToKFunction")
+        public void testFunctionReferenceErasedToKFunction() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithJava/reflection/functionReferenceErasedToKFunction/");
+            doTestWithJava(fileName);
+        }
+
         @TestMetadata("javaPropertyInheritedInKotlin")
         public void testJavaPropertyInheritedInKotlin() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithJava/reflection/javaPropertyInheritedInKotlin/");

compiler/tests/org/jetbrains/kotlin/codegen/generated/BlackBoxWithStdlibCodegenTestGenerated.java

@@ -513,6 +513,12 @@ public class BlackBoxWithStdlibCodegenTestGenerated extends AbstractBlackBoxCode
                 doTestWithStdlib(fileName);
             }
 
+            @TestMetadata("listOfStringsMapLength.kt")
+            public void testListOfStringsMapLength() throws Exception {
+                String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/callableReference/function/listOfStringsMapLength.kt");
+                doTestWithStdlib(fileName);
+            }
+
             @TestMetadata("nestedConstructorFromClass.kt")
             public void testNestedConstructorFromClass() throws Exception {
                 String fileName = JetTestUtils.navigationMetadata("compiler/testData/codegen/boxWithStdlib/callableReference/function/nestedConstructorFromClass.kt");