Implement quickfix to remove '.java' when KClass is expected

Fixes #KT-11078

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

@@ -0,0 +1,82 @@
+/*
+ * Copyright 2010-2016 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.idea.quickfix
+
+import com.intellij.codeInsight.intention.IntentionAction
+import com.intellij.openapi.editor.Editor
+import com.intellij.openapi.project.Project
+import com.intellij.psi.PsiFile
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
+import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.diagnostics.Diagnostic
+import org.jetbrains.kotlin.diagnostics.Errors
+import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.psi.KtDotQualifiedExpression
+import org.jetbrains.kotlin.psi.KtExpression
+import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi.psiUtil.endOffset
+import org.jetbrains.kotlin.psi.psiUtil.startOffset
+import org.jetbrains.kotlin.resolve.descriptorUtil.fqNameSafe
+import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+import org.jetbrains.kotlin.types.KotlinType
+import org.jetbrains.kotlin.types.typeUtil.isSubtypeOf
+
+private val JAVA_LANG_CLASS_FQ_NAME = FqName("java.lang.Class")
+
+private fun KotlinType.isJClass(): Boolean {
+    val expressionTypeFqName = constructor.declarationDescriptor?.fqNameSafe ?: return false
+    return expressionTypeFqName == JAVA_LANG_CLASS_FQ_NAME
+}
+
+class ConvertClassToKClassFix(element: KtDotQualifiedExpression, private val type: KotlinType) : KotlinQuickFixAction<KtDotQualifiedExpression>(element) {
+    override fun getText() = "Remove '.${element.children.lastOrNull()?.text}'"
+    override fun getFamilyName() = "Remove conversion from 'KClass' to 'Class'"
+
+
+    override fun isAvailable(project: Project, editor: Editor?, file: PsiFile): Boolean {
+        if (!super.isAvailable(project, editor, file)) return false
+
+        val expressionType = element.analyze(BodyResolveMode.PARTIAL).getType(element) ?: return false
+        if (!expressionType.isJClass()) return false
+
+        val children = element.children
+        if (children.size != 2) return false
+
+        val firstChild = children.first() as? KtExpression ?: return false
+        val firstChildType = firstChild.analyze(BodyResolveMode.PARTIAL).getType(firstChild) ?: return false
+
+        return firstChildType.isSubtypeOf(type)
+    }
+
+    override fun invoke(project: Project, editor: Editor?, file: KtFile) {
+        val lastChild = element.children.lastOrNull() ?: return
+        editor?.document?.replaceString(lastChild.startOffset - 1, lastChild.endOffset, "")
+    }
+
+    object Factory : KotlinIntentionActionsFactory() {
+        override fun doCreateActions(diagnostic: Diagnostic): List<IntentionAction> {
+            val casted = Errors.TYPE_INFERENCE_EXPECTED_TYPE_MISMATCH.cast(diagnostic)
+
+            val expectedClassDescriptor = casted.a.constructor.declarationDescriptor as? ClassDescriptor ?: return emptyList()
+            if (!KotlinBuiltIns.isKClass(expectedClassDescriptor)) return emptyList()
+
+            val element = casted.psiElement.parent as? KtDotQualifiedExpression ?: return emptyList()
+            return listOf(ConvertClassToKClassFix(element, casted.a))
+        }
+    }
+}

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

@@ -338,6 +338,8 @@ class QuickFixRegistrar : QuickFixContributor {
         UPPER_BOUND_VIOLATED.registerFactory(AddGenericUpperBoundFix.Factory)
         TYPE_INFERENCE_UPPER_BOUND_VIOLATED.registerFactory(AddGenericUpperBoundFix.Factory)
 
+        TYPE_INFERENCE_EXPECTED_TYPE_MISMATCH.registerFactory(ConvertClassToKClassFix.Factory)
+
         NON_CONST_VAL_USED_IN_CONSTANT_EXPRESSION.registerFactory(ConstFixFactory)
 
         OPERATOR_MODIFIER_REQUIRED.registerFactory(AddModifierFixFactory(KtTokens.OPERATOR_KEYWORD))

idea/testData/quickfix/typeInferenceExpectedTypeMismatch/convertClassToKClass1Runtime.kt

@@ -0,0 +1,9 @@
+// "Remove '.java'" "true"
+fun foo() {
+    bar(Foo::class.java<caret>)
+}
+
+class Foo
+
+fun bar(kc: kotlin.reflect.KClass<Foo>) {
+}

idea/testData/quickfix/typeInferenceExpectedTypeMismatch/convertClassToKClass1Runtime.kt.after

@@ -0,0 +1,9 @@
+// "Remove '.java'" "true"
+fun foo() {
+    bar(Foo::class<caret>)
+}
+
+class Foo
+
+fun bar(kc: kotlin.reflect.KClass<Foo>) {
+}

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

@@ -7097,6 +7097,21 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
         }
     }
 
+    @TestMetadata("idea/testData/quickfix/typeInferenceExpectedTypeMismatch")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class TypeInferenceExpectedTypeMismatch extends AbstractQuickFixTest {
+        public void testAllFilesPresentInTypeInferenceExpectedTypeMismatch() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/quickfix/typeInferenceExpectedTypeMismatch"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), true);
+        }
+
+        @TestMetadata("convertClassToKClass1Runtime.kt")
+        public void testConvertClassToKClass1Runtime() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/typeInferenceExpectedTypeMismatch/convertClassToKClass1Runtime.kt");
+            doTest(fileName);
+        }
+    }
+
     @TestMetadata("idea/testData/quickfix/typeMismatch")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)