Share const-error messages.

pkg/dart_messages/bin/publish.dart

 // Copyright (c) 2015, 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 'dart:convert';
 import 'dart:io' as io;
 
 import '../lib/shared_messages.dart';
 
 const String jsonPath = '../lib/generated/shared_messages.json';
@@ skipping 94 matching lines @@
     if (message.howToFix != null) {
       out.write(",\n    howToFix: ${escapeString(message.howToFix)}");
     }
     if (message.options != null) {
       out.write(",\n    options: const [");
       out.write(message.options.map(escapeString).join(","));
       out.writeln("]");
     }
     if (message.examples != null) {
       out.writeln(",\n    examples: const [");
+
+      String escapeExampleContent(String content) {
+        if (content.contains("\n") || content.contains('"')) {
+          return 'r"""\n$content"""';
+        } else if (content.contains("\\")) {
+          return 'r"$content"';
+        }
+        return '"$content"';
+      }
       for (var example in message.examples) {
         if (example is String) {
-          out.writeln("      r'''");
-          out.write(example);
-          out.write("'''");
+          out.write("      ");
+          out.write(escapeExampleContent(example));
         } else if (example is Map) {
           out.writeln("      const {");
           example.forEach((String fileName, String content) {
-            out.writeln("      '$fileName': r'''");
-            out.write(content);
-            out.writeln("''',");
+            out.writeln("      '$fileName': ");
+            out.write(escapeExampleContent(content));
+            out.writeln(",");
           });
           out.write("      }");
         }
         out.writeln(",");
       }
       out.writeln("    ]");
     }
     out.writeln("  ),  // Generated. Don't edit.");
   });
   out.writeln("};");
@@ skipping 77 matching lines @@
 /// Translates the shared messages in `../lib/shared_messages.dart` to JSON,
 /// dart2js, and analyzer formats.
 ///
 /// Emits the json-output to [jsonPath], the dart2js-output to [dart2jsPath],
 /// and the analyzer-output to [analyzerPath].
 void main() {
   emitJson();
   emitDart2js();
   emitAnalyzer();
 }