feature: tag tests; choose tags on command line

lib/src/utils.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.
 
 library test.utils;
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:math' as math;
 
@@ skipping 171 matching lines @@
   var result = {};
   map1.forEach((key, value) {
     result[key] = value;
   });
   map2.forEach((key, value) {
     result[key] = value;
   });
   return result;
 }
 
+/// Returns a new list with all elements in both [list1] and [list2].
+///
+/// If an element exists in both lists, it is listed only once in the result.
+List mergeLists(List list1, List list2) {
+  var result = []..addAll(list1);
+  list2.forEach((element) {
+    if (!result.contains(element)) {
+      result.add(element);
+    }
+  });
+  return result;
+}
+
 /// Returns a sink that maps events sent to [original] using [fn].
 StreamSink mapSink(StreamSink original, fn(event)) {
   var controller = new StreamController(sync: true);
   controller.stream.listen(
       (event) => original.add(fn(event)),
       onError: (error, stackTrace) => original.addError(error, stackTrace),
       onDone: () => original.close());
   return controller.sink;
 }
 
@@ skipping 194 matching lines @@
       urlSafe: urlSafe, addLineSeparator: addLineSeparator);
 }
 
 /// Returns middleware that nests all requests beneath the URL prefix [beneath].
 shelf.Middleware nestingMiddleware(String beneath) {
   return (handler) {
     var pathHandler = new PathHandler()..add(beneath, handler);
     return pathHandler.handler;
   };
 }
+
+/// Returns `true` iff [a] and [b] are both not null and share at least one
+/// element.
+bool intersect(Iterable a, Iterable b) {
+  return a != null && b != null && a.any(b.contains);
+}