Add the ability to add tags in the test config.

lib/src/runner/configuration.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:io';
 
 import 'package:collection/collection.dart';
 import 'package:glob/glob.dart';
 import 'package:path/path.dart' as p;
 
@@ skipping 96 matching lines @@
   /// tags.
   final Set<String> excludeTags;
 
   /// Configuration for particular tags.
   ///
   /// The keys are tag names, and the values are configuration for those tags.
   /// The configuration should only contain test-level configuration fields, but
   /// that isn't enforced.
   final Map<String, Configuration> tags;
 
+  final Set<String> addTags;
+
   /// The global test metadata derived from this configuration.
   Metadata get metadata => new Metadata(
       timeout: timeout,
       verboseTrace: verboseTrace,
+      tags: addTags,
       forTag: mapMap(tags, value: (_, config) => config.metadata));
 
   /// The set of tags that have been declaredin any way in this configuration.
   Set<String> get knownTags {
     if (_knownTags != null) return _knownTags;
 
-    var known = includeTags.union(excludeTags);
+    var known = includeTags.union(excludeTags).union(addTags);
     tags.forEach((tag, config) {
       known.add(tag);
       known.addAll(config.knownTags);
     });
 
     _knownTags = new UnmodifiableSetView(known);
     return _knownTags;
   }
   Set<String> _knownTags;
 
   /// Parses the configuration from [args].
   ///
   /// Throws a [FormatException] if [args] are invalid.
   factory Configuration.parse(List<String> arguments) => args.parse(arguments);
 
   /// Loads the configuration from [path].
   ///
   /// Throws an [IOException] if [path] does not exist or cannot be read. Throws
   /// a [FormatException] if its contents are invalid.
   factory Configuration.load(String path) => load(path);
 
   Configuration({bool help, bool version, bool verboseTrace, bool jsTrace,
           bool pauseAfterLoad, bool color, String packageRoot, String reporter,
           int pubServePort, int concurrency, Timeout timeout, this.pattern,
           Iterable<TestPlatform> platforms, Iterable<String> paths,
           Glob filename, Iterable<String> includeTags,
-          Iterable<String> excludeTags, Map<String, Configuration> tags})
+          Iterable<String> excludeTags, Iterable<String> addTags,
+          Map<String, Configuration> tags})
       : _help = help,
         _version = version,
         _verboseTrace = verboseTrace,
         _jsTrace = jsTrace,
         _pauseAfterLoad = pauseAfterLoad,
         _color = color,
         _packageRoot = packageRoot,
         _reporter = reporter,
         pubServeUrl = pubServePort == null
             ? null
             : Uri.parse("http://localhost:$pubServePort"),
         _concurrency = concurrency,
         timeout = (pauseAfterLoad ?? false)
             ? Timeout.none
             : (timeout == null ? new Timeout.factor(1) : timeout),
         _platforms = _list(platforms),
         _paths = _list(paths),
         _filename = filename,
         includeTags = includeTags?.toSet() ?? new Set(),
         excludeTags = excludeTags?.toSet() ?? new Set(),
+        addTags = addTags?.toSet() ?? new Set(),
         tags = tags == null ? const {} : new Map.unmodifiable(tags) {
     if (_filename != null && _filename.context.style != p.style) {
       throw new ArgumentError(
           "filename's context must match the current operating system, was "
               "${_filename.context.style}.");
     }
   }
 
   /// Returns a [input] as a list or `null`.
   ///
@@ skipping 23 matching lines @@
         reporter: other._reporter ?? _reporter,
         pubServePort: (other.pubServeUrl ?? pubServeUrl)?.port,
         concurrency: other._concurrency ?? _concurrency,
         timeout: timeout.merge(other.timeout),
         pattern: other.pattern ?? pattern,
         platforms: other._platforms ?? _platforms,
         paths: other._paths ?? _paths,
         filename: other._filename ?? _filename,
         includeTags: other.includeTags.union(includeTags),
         excludeTags: other.excludeTags.union(excludeTags),
+        addTags: other.addTags.union(addTags),
         tags: mergeMaps(tags, other.tags,
             value: (config1, config2) => config1.merge(config2)));
   }
 }