Add quickfix for adding 'lateinit'

Fixes #KT-17650

Author: cypressious

compiler/frontend/src/org/jetbrains/kotlin/psi/addRemoveModifier.kt

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2016 JetBrains s.r.o.
+ * Copyright 2010-2017 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.
@@ -136,6 +136,7 @@ private val MODIFIERS_TO_REPLACE = mapOf(
 private val MODIFIERS_ORDER = listOf(PUBLIC_KEYWORD, PROTECTED_KEYWORD, PRIVATE_KEYWORD, INTERNAL_KEYWORD,
                                      FINAL_KEYWORD, OPEN_KEYWORD, ABSTRACT_KEYWORD,
                                      OVERRIDE_KEYWORD,
+                                     LATEINIT_KEYWORD,
                                      SUSPEND_KEYWORD,
                                      INNER_KEYWORD,
                                      ENUM_KEYWORD, COMPANION_KEYWORD, INFIX_KEYWORD, OPERATOR_KEYWORD, DATA_KEYWORD)

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2015 JetBrains s.r.o.
+ * Copyright 2010-2017 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.
@@ -21,8 +21,11 @@ import com.intellij.openapi.editor.Editor
 import com.intellij.openapi.project.Project
 import com.intellij.psi.PsiFile
 import com.intellij.psi.PsiNameIdentifierOwner
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.diagnostics.Diagnostic
+import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
 import org.jetbrains.kotlin.idea.core.quickfix.QuickFixUtil
 import org.jetbrains.kotlin.idea.refactoring.canRefactor
@@ -34,6 +37,7 @@ import org.jetbrains.kotlin.psi.psiUtil.containingClassOrObject
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
+import org.jetbrains.kotlin.types.TypeUtils
 
 open class AddModifierFix(
         element: KtModifierListOwner,
@@ -116,4 +120,20 @@ open class AddModifierFix(
             return AddModifierFix(declaration, KtTokens.OPEN_KEYWORD)
         }
     }
+
+    object AddLateinitFactory : KotlinSingleIntentionActionFactory() {
+        override fun createAction(diagnostic: Diagnostic): IntentionAction? {
+            val property = Errors.MUST_BE_INITIALIZED_OR_BE_ABSTRACT.cast(diagnostic).psiElement
+            if (!property.isVar) return null
+
+            val context = property.analyze()
+            val descriptor = context[BindingContext.DECLARATION_TO_DESCRIPTOR, property] ?: return null
+            val type = (descriptor as? PropertyDescriptor)?.type ?: return null
+
+            if (TypeUtils.isNullableType(type)) return null
+            if (KotlinBuiltIns.isPrimitiveType(type)) return null
+
+            return AddModifierFix(property, KtTokens.LATEINIT_KEYWORD)
+        }
+    }
 }

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

@@ -489,5 +489,7 @@ class QuickFixRegistrar : QuickFixContributor {
         INAPPLICABLE_JVM_FIELD.registerFactory(ReplaceJvmFieldWithConstFix)
 
         CONFLICTING_OVERLOADS.registerFactory(ChangeSuspendInHierarchyFix)
+
+        MUST_BE_INITIALIZED_OR_BE_ABSTRACT.registerFactory(AddModifierFix.AddLateinitFactory)
     }
 }

idea/testData/quickfix/modifiers/addLateinit.kt

@@ -0,0 +1,5 @@
+// "Add 'lateinit' modifier" "true"
+
+class A {
+    private var a: String<caret>
+}

idea/testData/quickfix/modifiers/addLateinit.kt.after

@@ -0,0 +1,5 @@
+// "Add 'lateinit' modifier" "true"
+
+class A {
+    private lateinit var a: String<caret>
+}

idea/testData/quickfix/modifiers/noLateinitOnNullable.kt

@@ -0,0 +1,10 @@
+// "Add 'lateinit' modifier" "false"
+// ACTION: Add initializer
+// ACTION: Make 'a' abstract
+// ACTION: Move to constructor parameters
+// ACTION: Move to constructor
+// ERROR: Property must be initialized or be abstract
+
+class A {
+    private var a: String?<caret>
+}

idea/testData/quickfix/modifiers/noLateinitOnPrimitive.kt

@@ -0,0 +1,10 @@
+// "Add 'lateinit' modifier" "false"
+// ACTION: Add initializer
+// ACTION: Make 'a' abstract
+// ACTION: Move to constructor parameters
+// ACTION: Move to constructor
+// ERROR: Property must be initialized or be abstract
+
+class A {
+    private var a: Int<caret>
+}

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

@@ -6613,6 +6613,12 @@ public void testAbstractModifierInEnum() throws Exception {
             doTest(fileName);
         }
 
+        @TestMetadata("addLateinit.kt")
+        public void testAddLateinit() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/modifiers/addLateinit.kt");
+            doTest(fileName);
+        }
+
         public void testAllFilesPresentInModifiers() throws Exception {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("idea/testData/quickfix/modifiers"), Pattern.compile("^([\\w\\-_]+)\\.kt$"), TargetBackend.ANY, true);
         }
@@ -6671,6 +6677,18 @@ public void testNoAbstractForObject() throws Exception {
             doTest(fileName);
         }
 
+        @TestMetadata("noLateinitOnNullable.kt")
+        public void testNoLateinitOnNullable() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/modifiers/noLateinitOnNullable.kt");
+            doTest(fileName);
+        }
+
+        @TestMetadata("noLateinitOnPrimitive.kt")
+        public void testNoLateinitOnPrimitive() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/modifiers/noLateinitOnPrimitive.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("notAnAnnotationClass.kt")
         public void testNotAnAnnotationClass() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/modifiers/notAnAnnotationClass.kt");