Add quickfix to change object to class

#KT-33586 Fixed

compiler/psi/src/org/jetbrains/kotlin/psi/KtPsiFactory.kt

@@ -472,6 +472,8 @@ class KtPsiFactory @JvmOverloads constructor(private val project: Project, val m
         return file.importDirectives
     }
 
+    fun createClassKeyword(): PsiElement = createClass("class A").getClassKeyword()!!
+
     fun createPrimaryConstructor(text: String = ""): KtPrimaryConstructor {
         return createClass(if (text.isNotEmpty()) "class A $text" else "class A()").primaryConstructor!!
     }

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

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.idea.quickfix
+
+import com.intellij.openapi.editor.Editor
+import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.diagnostics.Diagnostic
+import org.jetbrains.kotlin.psi.KtConstructor
+import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.psi.KtObjectDeclaration
+import org.jetbrains.kotlin.psi.KtPsiFactory
+import org.jetbrains.kotlin.psi.psiUtil.containingClassOrObject
+
+class ChangeObjectToClassFix(element: KtObjectDeclaration) : KotlinQuickFixAction<KtObjectDeclaration>(element) {
+    override fun getText(): String = "Change object to class"
+
+    override fun getFamilyName(): String = text
+
+    override fun invoke(project: Project, editor: Editor?, file: KtFile) {
+        val objectDeclaration = element ?: return
+        val psiFactory = KtPsiFactory(objectDeclaration)
+        objectDeclaration.getObjectKeyword()?.replace(psiFactory.createClassKeyword())
+        objectDeclaration.replace(psiFactory.createClass(objectDeclaration.text))
+    }
+
+    companion object : KotlinSingleIntentionActionFactory() {
+        override fun createAction(diagnostic: Diagnostic): KotlinQuickFixAction<KtObjectDeclaration>? {
+            val element = diagnostic.psiElement as? KtConstructor<*> ?: return null
+            val containingObject = element.containingClassOrObject as? KtObjectDeclaration ?: return null
+            return ChangeObjectToClassFix(containingObject)
+        }
+    }
+}

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

@@ -614,6 +614,8 @@ class QuickFixRegistrar : QuickFixContributor {
 
         UNEXPECTED_TRAILING_LAMBDA_ON_A_NEW_LINE.registerFactory(AddSemicolonBeforeLambdaExpressionFix.Factory)
 
+        CONSTRUCTOR_IN_OBJECT.registerFactory(ChangeObjectToClassFix)
+
         REDUNDANT_LABEL_WARNING.registerFactory(RemoveRedundantLabelFix)
     }
 }

idea/testData/quickfix/changeObjectToClass/primaryConstructor.kt

@@ -0,0 +1,8 @@
+// "Change object to class" "true"
+annotation class Ann
+
+// comment
+@Ann
+object Foo<caret>(val s: String) : Any() {
+    constructor() : this("")
+}

idea/testData/quickfix/changeObjectToClass/primaryConstructor.kt.after

@@ -0,0 +1,8 @@
+// "Change object to class" "true"
+annotation class Ann
+
+// comment
+@Ann
+class Foo(val s: String) : Any() {
+    constructor() : this("")
+}

idea/testData/quickfix/changeObjectToClass/secondaryConstructor.kt

@@ -0,0 +1,8 @@
+// "Change object to class" "true"
+annotation class Ann
+
+// comment
+@Ann
+object Foo(val s: String) : Any() {
+    <caret>constructor() : this("")
+}

idea/testData/quickfix/changeObjectToClass/secondaryConstructor.kt.after

@@ -0,0 +1,8 @@
+// "Change object to class" "true"
+annotation class Ann
+
+// comment
+@Ann
+class Foo(val s: String) : Any() {
+    constructor() : this("")
+}

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

@@ -1197,6 +1197,19 @@ public class QuickFixMultiFileTestGenerated extends AbstractQuickFixMultiFileTes
         }
     }
 
+    @TestMetadata("idea/testData/quickfix/changeObjectToClass")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class ChangeObjectToClass extends AbstractQuickFixMultiFileTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTestWithExtraFile, TargetBackend.ANY, testDataFilePath);
+        }
+
+        public void testAllFilesPresentInChangeObjectToClass() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/quickfix/changeObjectToClass"), Pattern.compile("^(\\w+)\\.((before\\.Main\\.\\w+)|(test))$"), TargetBackend.ANY, true);
+        }
+    }
+
     @TestMetadata("idea/testData/quickfix/changeSignature")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

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

@@ -2057,6 +2057,29 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
         }
     }
 
+    @TestMetadata("idea/testData/quickfix/changeObjectToClass")
+    @TestDataPath("$PROJECT_ROOT")
+    @RunWith(JUnit3RunnerWithInners.class)
+    public static class ChangeObjectToClass extends AbstractQuickFixTest {
+        private void runTest(String testDataFilePath) throws Exception {
+            KotlinTestUtils.runTest(this::doTest, TargetBackend.ANY, testDataFilePath);
+        }
+
+        public void testAllFilesPresentInChangeObjectToClass() throws Exception {
+            KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/quickfix/changeObjectToClass"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
+        }
+
+        @TestMetadata("primaryConstructor.kt")
+        public void testPrimaryConstructor() throws Exception {
+            runTest("idea/testData/quickfix/changeObjectToClass/primaryConstructor.kt");
+        }
+
+        @TestMetadata("secondaryConstructor.kt")
+        public void testSecondaryConstructor() throws Exception {
+            runTest("idea/testData/quickfix/changeObjectToClass/secondaryConstructor.kt");
+        }
+    }
+
     @TestMetadata("idea/testData/quickfix/changeSignature")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)