"Remove redundant receiver" quick fix: Remove unused type parameter #KT-23512

idea/src/org/jetbrains/kotlin/idea/inspections/UnusedReceiverParameterInspection.kt

@@ -29,6 +29,7 @@ import org.jetbrains.kotlin.idea.caches.resolve.analyzeWithContent
 import org.jetbrains.kotlin.idea.caches.resolve.resolveToDescriptorIfAny
 import org.jetbrains.kotlin.idea.core.isOverridable
 import org.jetbrains.kotlin.idea.isMainFunction
+import org.jetbrains.kotlin.idea.quickfix.RemoveUnusedFunctionParameterFix
 import org.jetbrains.kotlin.idea.refactoring.changeSignature.KotlinChangeSignatureConfiguration
 import org.jetbrains.kotlin.idea.refactoring.changeSignature.KotlinMethodDescriptor
 import org.jetbrains.kotlin.idea.refactoring.changeSignature.modify
@@ -133,12 +134,13 @@ class UnusedReceiverParameterInspection : AbstractKotlinInspection() {
         }
 
         override fun applyFix(project: Project, descriptor: ProblemDescriptor) {
-            val element = descriptor.psiElement
+            val element = descriptor.psiElement as? KtTypeReference ?: return
             if (!FileModificationService.getInstance().preparePsiElementForWrite(element)) return
 
             val function = element.parent as? KtCallableDeclaration ?: return
             val callableDescriptor = function.resolveToDescriptorIfAny(BodyResolveMode.FULL) as? CallableDescriptor ?: return
 
+            val typeParameters = RemoveUnusedFunctionParameterFix.typeParameters(element)
             if (inSameClass) {
                 runWriteAction {
                     val explicateAsTextForReceiver = callableDescriptor.explicateAsTextForReceiver()
@@ -150,6 +152,7 @@ class UnusedReceiverParameterInspection : AbstractKotlinInspection() {
             } else {
                 runChangeSignature(project, callableDescriptor, configureChangeSignature(), element, name)
             }
+            RemoveUnusedFunctionParameterFix.runRemoveUnusedTypeParameters(typeParameters)
         }
 
         override fun getFamilyName(): String = name

idea/src/org/jetbrains/kotlin/idea/quickfix/RemoveUnusedFunctionParameterFix.kt

@@ -40,7 +40,7 @@ class RemoveUnusedFunctionParameterFix(parameter: KtParameter) : KotlinQuickFixA
         val parameterList = parameter.parent as? KtParameterList ?: return
         val parameterDescriptor = parameter.resolveToParameterDescriptorIfAny(BodyResolveMode.FULL) ?: return
         val parameterSize = parameterList.parameters.size
-        val typeParameters = typeParameters(parameter)
+        val typeParameters = typeParameters(parameter.typeReference)
         val primaryConstructor = parameterList.parent as? KtPrimaryConstructor
 
         ChangeFunctionSignatureFix.runRemoveParameter(parameterDescriptor, parameter)
@@ -64,31 +64,6 @@ class RemoveUnusedFunctionParameterFix(parameter: KtParameter) : KotlinQuickFixA
         }
     }
 
-    private fun typeParameters(parameter: KtParameter): List<KtTypeParameter> {
-        val parameterParent = parameter.getParentOfTypesAndPredicate(false, KtNamedFunction::class.java, KtClass::class.java) { true }
-        return parameter.typeReference?.typeElement
-            ?.collectDescendantsOfType<KtNameReferenceExpression> { true }
-            ?.mapNotNull {
-                val typeParameter = it.reference?.resolve() as? KtTypeParameter ?: return@mapNotNull null
-                val parent = typeParameter.getParentOfTypesAndPredicate(false, KtNamedFunction::class.java, KtClass::class.java) { true }
-                if (parent == parameterParent) typeParameter else null
-            } ?: emptyList()
-    }
-
-    private fun runRemoveUnusedTypeParameters(typeParameters: List<KtTypeParameter>) {
-        val unusedTypeParams = typeParameters.filter { ReferencesSearch.search(it).findFirst() == null }
-        if (unusedTypeParams.isEmpty()) return
-        runWriteAction {
-            unusedTypeParams.forEach { typeParameter ->
-                val typeParameterList = typeParameter.parent as? KtTypeParameterList ?: return@forEach
-                if (typeParameterList.parameters.size == 1)
-                    typeParameterList.delete()
-                else
-                    EditCommaSeparatedListHelper.removeItem(typeParameter)
-            }
-        }
-    }
-
     companion object : KotlinSingleIntentionActionFactory() {
         override fun createAction(diagnostic: Diagnostic): KotlinQuickFixAction<KtParameter>? {
             val parameter = Errors.UNUSED_PARAMETER.cast(diagnostic).psiElement
@@ -96,5 +71,37 @@ class RemoveUnusedFunctionParameterFix(parameter: KtParameter) : KotlinQuickFixA
             if (parameterOwner is KtFunctionLiteral || (parameterOwner is KtNamedFunction && parameterOwner.name == null)) return null
             return RemoveUnusedFunctionParameterFix(parameter)
         }
+
+        fun typeParameters(typeReference: KtTypeReference?): List<KtTypeParameter> {
+            if (typeReference == null) return emptyList()
+            val parameterParent = typeReference.getParentOfTypesAndPredicate(
+                true,
+                KtNamedFunction::class.java, KtProperty::class.java, KtClass::class.java
+            ) { true }
+            return typeReference.typeElement
+                ?.collectDescendantsOfType<KtNameReferenceExpression> { true }
+                ?.mapNotNull {
+                    val typeParameter = it.reference?.resolve() as? KtTypeParameter ?: return@mapNotNull null
+                    val parent = typeParameter.getParentOfTypesAndPredicate(
+                        true,
+                        KtNamedFunction::class.java, KtProperty::class.java, KtClass::class.java
+                    ) { true }
+                    if (parent == parameterParent) typeParameter else null
+                } ?: emptyList()
+        }
+
+        fun runRemoveUnusedTypeParameters(typeParameters: List<KtTypeParameter>) {
+            val unusedTypeParams = typeParameters.filter { ReferencesSearch.search(it).findFirst() == null }
+            if (unusedTypeParams.isEmpty()) return
+            runWriteAction {
+                unusedTypeParams.forEach { typeParameter ->
+                    val typeParameterList = typeParameter.parent as? KtTypeParameterList ?: return@forEach
+                    if (typeParameterList.parameters.size == 1)
+                        typeParameterList.delete()
+                    else
+                        EditCommaSeparatedListHelper.removeItem(typeParameter)
+                }
+            }
+        }
     }
 }

idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameter.kt

@@ -0,0 +1,5 @@
+fun <T> <caret>T.foo() {}
+
+fun test() {
+    "".foo()
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameter.kt.after

@@ -0,0 +1,5 @@
+fun foo() {}
+
+fun test() {
+    foo()
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameter2.kt

@@ -0,0 +1,5 @@
+fun <T> <caret>T.foo(t: T) {}
+
+fun test() {
+    "".foo("")
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameter2.kt.after

@@ -0,0 +1,5 @@
+fun <T> foo(t: T) {}
+
+fun test() {
+    foo("")
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameter3.kt

@@ -0,0 +1,7 @@
+interface TypeHolder<T, U>
+
+fun <T, U> <caret>TypeHolder<T, U>.foo() {}
+
+fun test(holder: TypeHolder<String, Int>) {
+    holder.foo()
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameter3.kt.after

@@ -0,0 +1,7 @@
+interface TypeHolder<T, U>
+
+fun foo() {}
+
+fun test(holder: TypeHolder<String, Int>) {
+    foo()
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameterInClass.kt

@@ -0,0 +1,7 @@
+class Test<T> {
+    fun <caret>T.foo() {}
+
+    fun test(t: T) {
+        t.foo()
+    }
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameterInClass.kt.after

@@ -0,0 +1,7 @@
+class Test<T> {
+    fun foo() {}
+
+    fun test(t: T) {
+        foo()
+    }
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameterInClass2.kt

@@ -0,0 +1,7 @@
+class Test<T> {
+    fun <U> <caret>U.foo() {}
+
+    fun test() {
+        "".foo()
+    }
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameterInClass2.kt.after

@@ -0,0 +1,7 @@
+class Test<T> {
+    fun foo() {}
+
+    fun test() {
+        foo()
+    }
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/propertyWithTypeParameter.kt

@@ -0,0 +1,6 @@
+val <T> <caret>T.bar: Int
+    get() = 1
+
+fun test() {
+    "".bar
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/propertyWithTypeParameter.kt.after

@@ -0,0 +1,6 @@
+val bar: Int
+    get() = 1
+
+fun test() {
+    bar
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/propertyWithTypeParameterInClass.kt

@@ -0,0 +1,8 @@
+class Test<T> {
+    val <caret>T.bar: Int
+        get() = 1
+
+    fun test(t: T) {
+        t.bar
+    }
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/propertyWithTypeParameterInClass.kt.after

@@ -0,0 +1,8 @@
+class Test<T> {
+    val bar: Int
+        get() = 1
+
+    fun test(t: T) {
+        bar
+    }
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/propertyWithTypeParameterInClass2.kt

@@ -0,0 +1,8 @@
+class Test<T> {
+    val <S> <caret>S.bar: Int
+        get() = 1
+
+    fun test() {
+        "".bar
+    }
+}

idea/testData/inspectionsLocal/unusedReceiverParameter/propertyWithTypeParameterInClass2.kt.after

@@ -0,0 +1,8 @@
+class Test<T> {
+    val bar: Int
+        get() = 1
+
+    fun test() {
+        bar
+    }
+}

idea/tests/org/jetbrains/kotlin/idea/inspections/LocalInspectionTestGenerated.java

@@ -6475,6 +6475,31 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
             runTest("idea/testData/inspectionsLocal/unusedReceiverParameter/functionInSameClass2.kt");
         }
 
+        @TestMetadata("functionWithTypeParameter.kt")
+        public void testFunctionWithTypeParameter() throws Exception {
+            runTest("idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameter.kt");
+        }
+
+        @TestMetadata("functionWithTypeParameter2.kt")
+        public void testFunctionWithTypeParameter2() throws Exception {
+            runTest("idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameter2.kt");
+        }
+
+        @TestMetadata("functionWithTypeParameter3.kt")
+        public void testFunctionWithTypeParameter3() throws Exception {
+            runTest("idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameter3.kt");
+        }
+
+        @TestMetadata("functionWithTypeParameterInClass.kt")
+        public void testFunctionWithTypeParameterInClass() throws Exception {
+            runTest("idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameterInClass.kt");
+        }
+
+        @TestMetadata("functionWithTypeParameterInClass2.kt")
+        public void testFunctionWithTypeParameterInClass2() throws Exception {
+            runTest("idea/testData/inspectionsLocal/unusedReceiverParameter/functionWithTypeParameterInClass2.kt");
+        }
+
         @TestMetadata("infix.kt")
         public void testInfix() throws Exception {
             runTest("idea/testData/inspectionsLocal/unusedReceiverParameter/infix.kt");
@@ -6494,6 +6519,21 @@ public class LocalInspectionTestGenerated extends AbstractLocalInspectionTest {
         public void testPropertyInSameClass() throws Exception {
             runTest("idea/testData/inspectionsLocal/unusedReceiverParameter/propertyInSameClass.kt");
         }
+
+        @TestMetadata("propertyWithTypeParameter.kt")
+        public void testPropertyWithTypeParameter() throws Exception {
+            runTest("idea/testData/inspectionsLocal/unusedReceiverParameter/propertyWithTypeParameter.kt");
+        }
+
+        @TestMetadata("propertyWithTypeParameterInClass.kt")
+        public void testPropertyWithTypeParameterInClass() throws Exception {
+            runTest("idea/testData/inspectionsLocal/unusedReceiverParameter/propertyWithTypeParameterInClass.kt");
+        }
+
+        @TestMetadata("propertyWithTypeParameterInClass2.kt")
+        public void testPropertyWithTypeParameterInClass2() throws Exception {
+            runTest("idea/testData/inspectionsLocal/unusedReceiverParameter/propertyWithTypeParameterInClass2.kt");
+        }
     }
 
     @TestMetadata("idea/testData/inspectionsLocal/unusedSymbol")