Issue 23018. Fix for inlining multiline strings with leading whitespaces.

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 239 matching lines @@
 ''');
     _createRefactoring('a =');
     // validate change
     return assertSuccessfulRefactoring(r'''
 main() {
   String b = "aaa bbb";
 }
 ''');
   }
 
+  test_OK_intoStringInterpolation_string_multiLineIntoMulti_leadingSpaces() {
+    indexTestUnit(r"""
+main() {
+  String a = '''\ \
+a
+a''';
+  String b = '''
+$a
+bbb''';
+}
+""");
+    _createRefactoring('a =');
+    // validate change
+    return assertSuccessfulRefactoring(r"""
+main() {
+  String b = '''
+a
+a
+bbb''';
+}
+""");
+  }
+
   test_OK_intoStringInterpolation_string_multiLineIntoMulti_unixEOL() {
     indexTestUnit(r"""
 main() {
   String a = '''
 a
 a
 a''';
   String b = '''
 $a
 bbb''';
@@ skipping 299 matching lines @@
     assertRefactoringStatus(status, 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);
   }
 }