Allow ClassName_methodName for a message name, easier to disambiguate duplicates

lib/src/intl_message.dart

 // Copyright (c) 2013, 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.
 
 /**
  * This provides classes to represent the internal structure of the
  * arguments to `Intl.message`. It is used when parsing sources to extract
  * messages or to generate code for message substitution. Normal programs
  * using Intl would not import this library.
  *
@@ skipping 75 matching lines @@
     var messageName = arguments.firstWhere((eachArg) =>
             eachArg is NamedExpression && eachArg.name.label.name == 'name',
         orElse: () => null);
     if (messageName == null) {
       return "The 'name' argument for Intl.message must be specified";
     }
     if (messageName.expression is! SimpleStringLiteral) {
       return "The 'name' argument for Intl.message must be a simple string "
           "literal.";
     }
-    if (outerName != null && outerName != messageName.expression.value) {
-      return "The 'name' argument for Intl.message must match "
-          "the name of the containing function ("
-          "'${messageName.expression.value}' vs. '$outerName')";
+    var hasOuterName = outerName != null;
+    var givenName = messageName.expression.value;
+    var simpleMatch = outerName == givenName;
+    ClassDeclaration classNode(n) {
+      if (n == null) return null;
+      if (n is ClassDeclaration) return n;
+      return classNode(n.parent);
+    }
+    var classDeclaration = classNode(node);
+    var classPlusMethod = classDeclaration == null
+        ? null
+        : "${classDeclaration.name.token.toString()}_$outerName";
+    var classMatch = classPlusMethod != null && (givenName == classPlusMethod);
+    if (!(hasOuterName && (simpleMatch || classMatch))) {
+      return "The 'name' argument for Intl.message must match either"
+          "the name of the containing function or <className>_<methodName> ("
+          "'$givenName' vs. '$outerName')";
     }
     var simpleArguments = arguments.where((each) => each is NamedExpression &&
         ["desc", "name"].contains(each.name.label.name));
     var values = simpleArguments.map((each) => each.expression).toList();
     for (var arg in values) {
       if (arg is! StringLiteral) {
         return ("Intl.message arguments must be string literals: $arg");
       }
     }
     return null;
@@ skipping 635 matching lines @@
     out.write('(');
     out.write(mainArgument);
     var args = codeAttributeNames;
     out.write(", {");
     args.fold(out,
         (buffer, arg) => buffer..write("'$arg': '${this[arg].toCode()}', "));
     out.write("})}");
     return out.toString();
   }
 }