Issue 21233. Improve inlining strings into string interpolations.

pkg/analysis_server/test/services/refactoring/inline_local_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.refactoring.inline_local;
 
 import 'package:analysis_server/src/protocol.dart' hide Element;
 import 'package:analysis_server/src/services/correction/status.dart';
 import 'package:analysis_server/src/services/refactoring/inline_local.dart';
 import 'package:analysis_server/src/services/refactoring/refactoring.dart';
@@ skipping 76 matching lines @@
     return assertSuccessfulRefactoring(r'''
 main() {
   print('test = ${1 + 2}');
   print('test = ${1 + 2}');
   print('test = ${process(1 + 2)}');
 }
 process(x) {}
 ''');
   }
 
+  test_OK_intoStringInterpolation_raw() {
+    indexTestUnit(r'''
+main() {
+  String a = r'an $ignored interpolation';
+  String b = '$a bbb';
+}
+''');
+    _createRefactoring('a =');
+    // we don't unwrap raw strings
+    return assertSuccessfulRefactoring(r'''
+main() {
+  String b = '${r'an $ignored interpolation'} bbb';
+}
+''');
+  }
+
+  test_OK_intoStringInterpolation_string() {
+    indexTestUnit(r'''
+main() {
+  String a = 'aaa';
+  String b = '$a bbb';
+}
+''');
+    _createRefactoring('a =');
+    // validate change
+    return assertSuccessfulRefactoring(r'''
+main() {
+  String b = 'aaa bbb';
+}
+''');
+  }
+
+  test_OK_intoStringInterpolation_stringInterpolation() {
+    indexTestUnit(r'''
+main() {
+  String a = 'aaa';
+  String b = '$a bbb';
+  String c = '$b ccc';
+}
+''');
+    _createRefactoring('b =');
+    // validate change
+    return assertSuccessfulRefactoring(r'''
+main() {
+  String a = 'aaa';
+  String c = '$a bbb ccc';
+}
+''');
+  }
+
   /**
    * <p>
    * https://code.google.com/p/dart/issues/detail?id=18587
    */
   test_OK_keepNextCommentedLine() {
     indexTestUnit('''
 main() {
   int test = 1 + 2;
   // foo
   print(test);
@@ skipping 213 matching lines @@
         RefactoringProblemSeverity.FATAL,
         expectedMessage: 'Local variable declaration or reference must be '
             'selected to activate this refactoring.');
   }
 
   void _createRefactoring(String search) {
     int offset = findOffset(search);
     refactoring = new InlineLocalRefactoring(searchEngine, testUnit, offset);
   }
 }