Change Signature: Fix TypeInfo comparison

#KT-13437 Fixed

idea/src/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinTypeInfo.kt

@@ -18,18 +18,22 @@ package org.jetbrains.kotlin.idea.refactoring.changeSignature
 
 import org.jetbrains.kotlin.idea.util.IdeDescriptorRenderers
 import org.jetbrains.kotlin.types.KotlinType
-import org.jetbrains.kotlin.types.TypeUtils
 
 data class KotlinTypeInfo(val isCovariant: Boolean, val type: KotlinType? = null, val text: String? = null)
 
 fun KotlinTypeInfo.render(): String {
     return when {
         text != null -> text
-        type != null -> (if (isCovariant) IdeDescriptorRenderers.SOURCE_CODE else IdeDescriptorRenderers.SOURCE_CODE_NOT_NULL_TYPE_APPROXIMATION).renderType(type)
+        type != null -> renderType()
         else -> ""
     }
 }
 
+private fun KotlinTypeInfo.renderType(): String {
+    val renderer = if (isCovariant) IdeDescriptorRenderers.SOURCE_CODE else IdeDescriptorRenderers.SOURCE_CODE_NOT_NULL_TYPE_APPROXIMATION
+    return renderer.renderType(type!!)
+}
+
 fun KotlinTypeInfo.isEquivalentTo(other: KotlinTypeInfo): Boolean {
-    return if (type != null && other.type != null) TypeUtils.equalTypes(type, other.type) else render() == other.render()
+    return if (type != null && other.type != null) renderType() == other.renderType() else text == other.text
 }

idea/src/org/jetbrains/kotlin/idea/refactoring/changeSignature/ui/KotlinChangeSignatureDialog.kt

@@ -407,7 +407,7 @@ class KotlinChangeSignatureDialog(
             }
         }
 
-        private fun getTypeCodeFragmentContext(startFrom: PsiElement): KtElement {
+        fun getTypeCodeFragmentContext(startFrom: PsiElement): KtElement {
             return startFrom.parentsWithSelf.mapNotNull {
                 when {
                     it is KtNamedFunction -> it.bodyExpression ?: it.valueParameterList
@@ -440,7 +440,7 @@ class KotlinChangeSignatureDialog(
             return KotlinChangeSignatureProcessor(project, changeInfo, commandName)
         }
 
-        private fun PsiCodeFragment?.getTypeInfo(isCovariant: Boolean, forPreview: Boolean): KotlinTypeInfo {
+        fun PsiCodeFragment?.getTypeInfo(isCovariant: Boolean, forPreview: Boolean): KotlinTypeInfo {
             if (this !is KtTypeCodeFragment) return KotlinTypeInfo(isCovariant)
 
             val typeRef = getContentElement()

idea/testData/refactoring/changeSignature/ReturnTypeViaCodeFragmentAfter.kt

@@ -0,0 +1,9 @@
+class A<T, U>
+
+interface I {
+    fun <T, U> bar(): A<T, U>
+}
+
+class C : I {
+    override fun <V, W> bar() = A<V, W>()
+}

idea/testData/refactoring/changeSignature/ReturnTypeViaCodeFragmentBefore.kt

@@ -0,0 +1,9 @@
+class A<T, U>
+
+interface I {
+    fun <T, U> <caret>foo(): A<T, U>
+}
+
+class C : I {
+    override fun <V, W> foo() = A<V, W>()
+}

idea/tests/org/jetbrains/kotlin/idea/refactoring/changeSignature/KotlinChangeSignatureTest.kt

@@ -38,6 +38,8 @@ import org.jetbrains.kotlin.builtins.DefaultBuiltIns
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.refactoring.changeSignature.ui.KotlinMethodNode
+import org.jetbrains.kotlin.idea.refactoring.changeSignature.ui.KotlinChangeSignatureDialog.Companion.getTypeInfo
+import org.jetbrains.kotlin.idea.refactoring.changeSignature.ui.KotlinChangeSignatureDialog.Companion.getTypeCodeFragmentContext
 import org.jetbrains.kotlin.idea.search.allScope
 import org.jetbrains.kotlin.idea.stubindex.KotlinFullClassNameIndex
 import org.jetbrains.kotlin.idea.stubindex.KotlinTopLevelFunctionFqnNameIndex
@@ -246,6 +248,11 @@ class KotlinChangeSignatureTest : KotlinLightCodeInsightFixtureTestCase() {
         setNewParameter(j, temp)
     }
 
+    private fun KotlinChangeInfo.resolveType(text: String, isCovariant: Boolean, forPreview: Boolean): KotlinTypeInfo {
+        val codeFragment = KtPsiFactory(project).createTypeCodeFragment(text, getTypeCodeFragmentContext(context))
+        return codeFragment.getTypeInfo(isCovariant, forPreview)
+    }
+
     // --------------------------------- Tests ---------------------------------
 
     fun testBadSelection() {
@@ -944,4 +951,9 @@ class KotlinChangeSignatureTest : KotlinLightCodeInsightFixtureTestCase() {
     fun testReceiverInSafeCall() = doTestConflict { receiverParameterInfo = null }
 
     fun testRemoveParameterKeepOtherComments() = doTest { removeParameter(1) }
+
+    fun testReturnTypeViaCodeFragment() = doTest {
+        newName = "bar"
+        newReturnTypeInfo = resolveType("A<T, U>", true, true)
+    }
 }