Convert lambda to reference: support generic function call

#KT-14578 Fixed
#KT-14395 Fixed

idea/src/org/jetbrains/kotlin/idea/intentions/ConvertLambdaToReferenceIntention.kt

@@ -88,7 +88,7 @@ open class ConvertLambdaToReferenceIntention(textGetter: () -> String) : SelfTar
         ) return false
 
         // No references with type parameters
-        if (calleeDescriptor.typeParameters.isNotEmpty()) return false
+        if (calleeDescriptor.typeParameters.isNotEmpty() && lambdaExpression.parentValueArgument() == null) return false
         // No references to Java synthetic properties
         if (calleeDescriptor is SyntheticJavaPropertyDescriptor) return false
 
@@ -237,6 +237,12 @@ open class ConvertLambdaToReferenceIntention(textGetter: () -> String) : SelfTar
                 }
                 lambdaArgument.delete()
             }
+
+            outerCallExpression.typeArgumentList?.let {
+                if (RemoveExplicitTypeArgumentsIntention.isApplicableTo(it, approximateFlexible = false)) {
+                    it.delete()
+                }
+            }
         }
     }
 
@@ -257,7 +263,9 @@ open class ConvertLambdaToReferenceIntention(textGetter: () -> String) : SelfTar
         val calledFunctionInLambda = lambda.singleStatementOrNull()
             ?.getResolvedCall(context)?.resultingDescriptor as? FunctionDescriptor ?: return
         val overloadedFunctions = calledFunctionInLambda.overloadedFunctions()
-        if (overloadedFunctions.count { it.valueParameters.size == calledFunctionInLambda.valueParameters.size } < 2) return
+        if (overloadedFunctions.count { it.valueParameters.size == calledFunctionInLambda.valueParameters.size } < 2
+            && calledFunctionInLambda.typeParameters.isEmpty()
+        ) return
 
         if (InsertExplicitTypeArgumentsIntention.isApplicableTo(this, context)) {
             InsertExplicitTypeArgumentsIntention.applyTo(this)

idea/testData/intentions/convertLambdaToReference/generic2.kt

@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+fun <T> foo(i: Int): T? = null
+
+fun test(list: List<Int>) {
+    list.mapNotNull <caret>{ foo<String>(it) }
+}

idea/testData/intentions/convertLambdaToReference/generic2.kt.after

@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+fun <T> foo(i: Int): T? = null
+
+fun test(list: List<Int>) {
+    list.mapNotNull<Int, String>(::foo)
+}

idea/testData/intentions/convertLambdaToReference/generic3.kt

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+interface CD
+
+fun <D : CD> D.foo(): D? = null
+
+fun test(x: List<CD>) {
+    x.mapNotNull <caret>{ it.foo() }
+}

idea/testData/intentions/convertLambdaToReference/generic3.kt.after

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+interface CD
+
+fun <D : CD> D.foo(): D? = null
+
+fun test(x: List<CD>) {
+    x.mapNotNull(CD::foo)
+}

idea/testData/intentions/convertLambdaToReference/generic4.kt

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun test() {
+    listOf(listOf(1)).filter <caret>{ it.isNotEmpty() }
+}

idea/testData/intentions/convertLambdaToReference/generic4.kt.after

@@ -0,0 +1,4 @@
+// WITH_RUNTIME
+fun test() {
+    listOf(listOf(1)).filter(List<Int>::isNotEmpty)
+}

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java

@@ -5095,6 +5095,21 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             runTest("idea/testData/intentions/convertLambdaToReference/generic.kt");
         }
 
+        @TestMetadata("generic2.kt")
+        public void testGeneric2() throws Exception {
+            runTest("idea/testData/intentions/convertLambdaToReference/generic2.kt");
+        }
+
+        @TestMetadata("generic3.kt")
+        public void testGeneric3() throws Exception {
+            runTest("idea/testData/intentions/convertLambdaToReference/generic3.kt");
+        }
+
+        @TestMetadata("generic4.kt")
+        public void testGeneric4() throws Exception {
+            runTest("idea/testData/intentions/convertLambdaToReference/generic4.kt");
+        }
+
         @TestMetadata("globalProperty.kt")
         public void testGlobalProperty() throws Exception {
             runTest("idea/testData/intentions/convertLambdaToReference/globalProperty.kt");