Add optional message to assert in Dart2js - continued

pkg/compiler/lib/src/diagnostics/messages.dart

 // Copyright (c) 2011, 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.
 
 
 /**
  * The messages in this file should meet the following guide lines:
  *
  * 1. The message should be a complete sentence starting with an uppercase
  * letter, and ending with a period.
@@ skipping 170 matching lines @@
   DUPLICATED_LIBRARY_NAME,
   DUPLICATED_LIBRARY_RESOURCE,
   DUPLICATED_PART_OF,
   DUPLICATED_RESOURCE,
   EMPTY_CATCH_DECLARATION,
   EMPTY_ENUM_DECLARATION,
   EQUAL_MAP_ENTRY_KEY,
   EXISTING_DEFINITION,
   EXISTING_LABEL,
   EXPECTED_IDENTIFIER_NOT_RESERVED_WORD,
+  EXPERIMENTAL_ASSERT_MESSAGE,
   EXPONENT_MISSING,
   EXPORT_BEFORE_PARTS,
   EXTERNAL_WITH_BODY,
   EXTRA_CATCH_DECLARATION,
   EXTRA_FORMALS,
   EXTRANEOUS_MODIFIER,
   EXTRANEOUS_MODIFIER_REPLACE,
   FACTORY_REDIRECTION_IN_NON_FACTORY,
   FINAL_FUNCTION_TYPE_PARAMETER,
   FINAL_WITHOUT_INITIALIZER,
@@ skipping 3061 matching lines @@
 main() => foo();
 """, """
 external foo() {}
 main() => foo();
 """]),
 
   //////////////////////////////////////////////////////////////////////////////
   // Patch errors end.
   //////////////////////////////////////////////////////////////////////////////
 
+      MessageKind.EXPERIMENTAL_ASSERT_MESSAGE:
+        const MessageTemplate(MessageKind.EXPERIMENTAL_ASSERT_MESSAGE,
+          "Experimental language feature 'assertion with message'"
+          " is not supported.",
+          howToFix:
+            "Use option '--assert-message' to use assertions with messages.",
+          examples: const [r'''
+main() {
+  int n = -7;
+  assert(n > 0, 'must be positive: $n');
+}
+''']),
+
       MessageKind.IMPORT_EXPERIMENTAL_MIRRORS:
         const MessageTemplate(MessageKind.IMPORT_EXPERIMENTAL_MIRRORS, r'''
 
 ****************************************************************
 * WARNING: dart:mirrors support in dart2js is experimental,
 *          and not recommended.
 *          This implementation of mirrors is incomplete,
 *          and often greatly increases the size of the generated
 *          JavaScript code.
 *
@@ skipping 121 matching lines @@
   static String convertToString(value) {
     if (value is ErrorToken) {
       // Shouldn't happen.
       return value.assertionMessage;
     } else if (value is Token) {
       value = value.value;
     }
     return '$value';
   }
 }