Issue 25095. Add 'Change X to Y type annotation' Quick Fix.

pkg/analysis_server/test/services/correction/fix_test.dart

 // Copyright (c) 2014, 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.
 
 library test.services.correction.fix;
 
 import 'dart:async';
 
 import 'package:analysis_server/plugin/edit/fix/fix_core.dart';
 import 'package:analysis_server/plugin/edit/fix/fix_dart.dart';
@@ skipping 579 matching lines @@
         DartFixKind.CHANGE_TO_STATIC_ACCESS,
         '''
 import 'libB.dart';
 import 'libA.dart';
 main(B b) {
   A.foo;
 }
 ''');
   }
 
+  test_changeTypeAnnotation_BAD_multipleVariables() async {
+    resolveTestUnit('''
+main() {
+  String a, b = 42;
+}
+''');
+    await assertNoFix(DartFixKind.CHANGE_TYPE_ANNOTATION);
+  }
+
+  test_changeTypeAnnotation_BAD_notVariableDeclaration() async {
+    resolveTestUnit('''
+main() {
+  String p;
+  p = 42;
+}
+''');
+    await assertNoFix(DartFixKind.CHANGE_TYPE_ANNOTATION);
+  }
+
+  test_changeTypeAnnotation_OK_generic() async {
+    resolveTestUnit('''
+main() {
+  String v = <int>[];
+}
+''');
+    await assertHasFix(
+        DartFixKind.CHANGE_TYPE_ANNOTATION,
+        '''
+main() {
+  List<int> v = <int>[];
+}
+''');
+  }
+
+  test_changeTypeAnnotation_OK_simple() async {
+    resolveTestUnit('''
+main() {
+  String v = 'abc'.length;
+}
+''');
+    await assertHasFix(
+        DartFixKind.CHANGE_TYPE_ANNOTATION,
+        '''
+main() {
+  int v = 'abc'.length;
+}
+''');
+  }
+
   test_createClass() async {
     resolveTestUnit('''
 main() {
   Test v = null;
 }
 ''');
     await assertHasFix(
         DartFixKind.CREATE_CLASS,
         '''
 main() {
@@ skipping 4113 matching lines @@
       int offset = resultCode.indexOf(search);
       positions.add(new Position(testFile, offset));
     }
     return positions;
   }
 
   void _performAnalysis() {
     while (context.performAnalysisTask().hasMoreWork);
   }
 }