Create from Usage: Allow type parameters in the receiver position

#KT-7497 Fixed

idea/src/org/jetbrains/kotlin/idea/quickfix/createFromUsage/callableBuilder/CallableBuilder.kt

@@ -72,10 +72,12 @@ import org.jetbrains.kotlin.resolve.scopes.utils.findClassifier
 import org.jetbrains.kotlin.resolve.scopes.utils.memberScopeAsImportingScope
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.TypeProjectionImpl
+import org.jetbrains.kotlin.types.TypeUtils
 import org.jetbrains.kotlin.types.Variance
 import org.jetbrains.kotlin.types.checker.KotlinTypeChecker
 import org.jetbrains.kotlin.types.typeUtil.isAnyOrNullableAny
 import org.jetbrains.kotlin.types.typeUtil.isUnit
+import org.jetbrains.kotlin.types.typeUtil.makeNullable
 import org.jetbrains.kotlin.utils.addToStdlib.singletonOrEmptyList
 import java.util.*
 import kotlin.properties.Delegates
@@ -223,7 +225,7 @@ class CallableBuilder(val config: CallableBuilderConfiguration) {
         val containingFileEditor: Editor
         val containingElement: PsiElement
         val dialogWithEditor: DialogWithEditor?
-        val receiverClassDescriptor: ClassDescriptor?
+        val receiverClassDescriptor: ClassifierDescriptor?
         val typeParameterNameMap: Map<TypeParameterDescriptor, String>
         val receiverTypeCandidate: TypeCandidate?
         val mandatoryTypeParametersAsCandidates: List<TypeCandidate>
@@ -247,7 +249,7 @@ class CallableBuilder(val config: CallableBuilderConfiguration) {
                 }
                 is CallablePlacement.WithReceiver -> {
                     receiverClassDescriptor =
-                            placement.receiverTypeCandidate.theType.getConstructor().getDeclarationDescriptor() as? ClassDescriptor
+                            placement.receiverTypeCandidate.theType.getConstructor().getDeclarationDescriptor()
                     val classDeclaration = receiverClassDescriptor?.let { DescriptorToSourceUtils.getSourceFromDescriptor(it) }
                     containingElement = if (!config.isExtension && classDeclaration != null) classDeclaration else config.currentFile
                 }
@@ -350,7 +352,7 @@ class CallableBuilder(val config: CallableBuilderConfiguration) {
 
             assert (receiverClassDescriptor is JavaClassDescriptor) { "Unexpected receiver class: $receiverClassDescriptor" }
 
-            val projections = receiverClassDescriptor.declaredTypeParameters
+            val projections = ((receiverClassDescriptor as JavaClassDescriptor).declaredTypeParameters)
                     .map { TypeProjectionImpl(it.getDefaultType()) }
             val memberScope = receiverClassDescriptor.getMemberScope(projections)
 

idea/src/org/jetbrains/kotlin/idea/quickfix/createFromUsage/createCallable/CreateCallableFromUsageFix.kt

@@ -73,7 +73,7 @@ public abstract class CreateCallableFromUsageFixBase<E : KtElement>(
     private fun getDeclarationIfApplicable(project: Project, candidate: TypeCandidate): PsiElement? {
         val descriptor = candidate.theType.constructor.declarationDescriptor ?: return null
         val declaration = getDeclaration(descriptor, project) ?: return null
-        if (declaration !is KtClassOrObject && declaration !is PsiClass) return null
+        if (declaration !is KtClassOrObject && declaration !is KtTypeParameter && declaration !is PsiClass) return null
         return if (isExtension || declaration.canRefactor()) declaration else null
     }
 
@@ -125,6 +125,7 @@ public abstract class CreateCallableFromUsageFixBase<E : KtElement>(
                     false
                 isFunction && insertToJavaInterface && receiverInfo.staticContextRequired ->
                     false
+                !isExtension && declaration is KtTypeParameter -> false
                 else ->
                     declaration != null
             }

idea/testData/quickfix/createFromUsage/createFunction/call/typeArguments/extensionWithTypeParameterAsReceiver.kt

@@ -0,0 +1,4 @@
+// "Create extension function 'bar'" "true"
+fun <T> foo(t: T) {
+    t.<caret>bar()
+}

idea/testData/quickfix/createFromUsage/createFunction/call/typeArguments/extensionWithTypeParameterAsReceiver.kt.after

@@ -0,0 +1,8 @@
+// "Create extension function 'bar'" "true"
+fun <T> foo(t: T) {
+    t.bar()
+}
+
+fun <T> T.bar() {
+    throw UnsupportedOperationException("not implemented") //To change body of created functions use File | Settings | File Templates.
+}

idea/testData/quickfix/createFromUsage/createFunction/call/typeArguments/memberWithTypeParameterAsReceiver.kt

@@ -0,0 +1,7 @@
+// "Create member function 'bar'" "false"
+// ACTION: Create extension function 'bar'
+// ACTION: Rename reference
+// ERROR: Unresolved reference: bar
+fun <T> foo(t: T) {
+    t.<caret>bar()
+}

idea/testData/quickfix/createFromUsage/createVariable/property/extensionWithTypeParameterAsReceiver.kt

@@ -0,0 +1,7 @@
+// "Create extension property 'bar'" "true"
+// ERROR: Property must be initialized
+fun consume(n: Int) {}
+
+fun <T> foo(t: T) {
+    consume(t.<caret>bar)
+}

idea/testData/quickfix/createFromUsage/createVariable/property/extensionWithTypeParameterAsReceiver.kt.after

@@ -0,0 +1,9 @@
+// "Create extension property 'bar'" "true"
+// ERROR: Property must be initialized
+fun consume(n: Int) {}
+
+val <T> T.bar: Int
+
+fun <T> foo(t: T) {
+    consume(t.bar)
+}

idea/testData/quickfix/createFromUsage/createVariable/property/memberWithTypeParameterAsReceiver.kt

@@ -0,0 +1,10 @@
+// "Create member property 'bar'" "false"
+// ACTION: Create extension property 'bar'
+// ACTION: Rename reference
+// ACTION: Convert to expression body
+// ERROR: Unresolved reference: bar
+fun consume(n: Int) {}
+
+fun <T> foo(t: T) {
+    consume(t.<caret>bar)
+}

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java

@@ -2119,6 +2119,18 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
                         doTest(fileName);
                     }
 
+                    @TestMetadata("extensionWithTypeParameterAsReceiver.kt")
+                    public void testExtensionWithTypeParameterAsReceiver() throws Exception {
+                        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/createFromUsage/createFunction/call/typeArguments/extensionWithTypeParameterAsReceiver.kt");
+                        doTest(fileName);
+                    }
+
+                    @TestMetadata("memberWithTypeParameterAsReceiver.kt")
+                    public void testMemberWithTypeParameterAsReceiver() throws Exception {
+                        String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/createFromUsage/createFunction/call/typeArguments/memberWithTypeParameterAsReceiver.kt");
+                        doTest(fileName);
+                    }
+
                     @TestMetadata("noReceiver.kt")
                     public void testNoReceiver() throws Exception {
                         String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/createFromUsage/createFunction/call/typeArguments/noReceiver.kt");
@@ -3065,6 +3077,12 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("extensionWithTypeParameterAsReceiver.kt")
+                public void testExtensionWithTypeParameterAsReceiver() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/createFromUsage/createVariable/property/extensionWithTypeParameterAsReceiver.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("inBinaryOperation.kt")
                 public void testInBinaryOperation() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/createFromUsage/createVariable/property/inBinaryOperation.kt");
@@ -3113,6 +3131,12 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
                     doTest(fileName);
                 }
 
+                @TestMetadata("memberWithTypeParameterAsReceiver.kt")
+                public void testMemberWithTypeParameterAsReceiver() throws Exception {
+                    String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/createFromUsage/createVariable/property/memberWithTypeParameterAsReceiver.kt");
+                    doTest(fileName);
+                }
+
                 @TestMetadata("objectMemberValNoReceiver.kt")
                 public void testObjectMemberValNoReceiver() throws Exception {
                     String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/createFromUsage/createVariable/property/objectMemberValNoReceiver.kt");