new fix: MAKE_VARIABLE_NOT_FINAL

Fixes: #33290

Change-Id: Ice1c11907ed696d9d209145a4cacf2ca250c17c6
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/115273
Commit-Queue: Phil Quitslund <pquitslund@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>

Author: pq

pkg/analysis_server/lib/src/services/correction/fix.dart

@@ -238,6 +238,8 @@ class DartFixKind {
       'MOVE_TYPE_ARGUMENTS_TO_CLASS',
       50,
       "Move type arguments to after class name");
+  static const MAKE_VARIABLE_NOT_FINAL = const FixKind(
+      'MAKE_VARIABLE_NOT_FINAL', 50, "Make variable '{0}' not final");
   static const REMOVE_ANNOTATION =
       const FixKind('REMOVE_ANNOTATION', 50, "Remove the '{0}' annotation");
   static const REMOVE_AWAIT = const FixKind('REMOVE_AWAIT', 50, "Remove await");

pkg/analysis_server/lib/src/services/correction/fix_internal.dart

@@ -412,6 +412,9 @@ class FixProcessor {
     if (errorCode == StaticWarningCode.ASSIGNMENT_TO_FINAL) {
       await _addFix_makeFieldNotFinal();
     }
+    if (errorCode == StaticWarningCode.ASSIGNMENT_TO_FINAL_LOCAL) {
+      await _addFix_makeVariableNotFinal();
+    }
     if (errorCode == StaticWarningCode.CONCRETE_CLASS_WITH_ABSTRACT_MEMBER) {
       await _addFix_makeEnclosingClassAbstract();
     }
@@ -2647,6 +2650,37 @@ class FixProcessor {
     }
   }
 
+  Future<void> _addFix_makeVariableNotFinal() async {
+    AstNode node = this.node;
+    if (node is SimpleIdentifier &&
+        node.staticElement is LocalVariableElement) {
+      LocalVariableElement variable = node.staticElement;
+      var id = NodeLocator(variable.nameOffset).searchWithin(unit);
+      var decl = id?.parent;
+      if (decl is VariableDeclaration &&
+          decl.parent is VariableDeclarationList) {
+        VariableDeclarationList declarationList = decl.parent;
+        var keywordToken = declarationList.keyword;
+        if (declarationList.variables.length == 1 &&
+            keywordToken.keyword == Keyword.FINAL) {
+          var changeBuilder = _newDartChangeBuilder();
+          await changeBuilder.addFileEdit(file, (DartFileEditBuilder builder) {
+            if (declarationList.type != null) {
+              builder.addDeletion(
+                  range.startStart(keywordToken, declarationList.type));
+            } else {
+              builder.addSimpleReplacement(range.token(keywordToken), 'var');
+            }
+          });
+          declarationList.variables[0].name.name;
+          var varName = declarationList.variables[0].name.name;
+          _addFixFromBuilder(changeBuilder, DartFixKind.MAKE_VARIABLE_NOT_FINAL,
+              args: [varName]);
+        }
+      }
+    }
+  }
+
   Future<void> _addFix_moveTypeArgumentsToClass() async {
     if (coveredNode is TypeArgumentList) {
       TypeArgumentList typeArguments = coveredNode;

pkg/analysis_server/test/src/services/correction/fix/make_variable_not_final_test.dart

@@ -0,0 +1,55 @@
+// Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:analysis_server/src/services/correction/fix.dart';
+import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
+import 'package:test_reflective_loader/test_reflective_loader.dart';
+
+import 'fix_processor.dart';
+
+main() {
+  defineReflectiveSuite(() {
+    defineReflectiveTests(MakeVariableNotFinalTest);
+  });
+}
+
+@reflectiveTest
+class MakeVariableNotFinalTest extends FixProcessorTest {
+  @override
+  FixKind get kind => DartFixKind.MAKE_VARIABLE_NOT_FINAL;
+
+  test_hasType() async {
+    await resolveTestUnit('''
+main() {
+  final int fff = 1;
+  fff = 2;
+  print(fff);
+}
+''');
+    await assertHasFix('''
+main() {
+  int fff = 1;
+  fff = 2;
+  print(fff);
+}
+''');
+  }
+
+  test_noType() async {
+    await resolveTestUnit('''
+main() {
+  final fff = 1;
+  fff = 2;
+  print(fff);
+}
+''');
+    await assertHasFix('''
+main() {
+  var fff = 1;
+  fff = 2;
+  print(fff);
+}
+''');
+  }
+}

pkg/analysis_server/test/src/services/correction/fix/test_all.dart

@@ -59,6 +59,7 @@ import 'insert_semicolon_test.dart' as insert_semicolon;
 import 'make_class_abstract_test.dart' as make_class_abstract;
 import 'make_field_not_final_test.dart' as make_field_not_final;
 import 'make_final_test.dart' as make_final;
+import 'make_variable_not_final_test.dart' as make_variable_not_final;
 import 'move_type_arguments_to_class_test.dart' as move_type_arguments_to_class;
 import 'remove_annotation_test.dart' as remove_annotation;
 import 'remove_await_test.dart' as remove_await;
@@ -161,6 +162,7 @@ main() {
     make_class_abstract.main();
     make_field_not_final.main();
     make_final.main();
+    make_variable_not_final.main();
     move_type_arguments_to_class.main();
     remove_annotation.main();
     remove_await.main();