feature: tag tests; choose tags on command line

lib/src/backend/metadata.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.
 
 library test.backend.metadata;
 
 import 'dart:collection';
 
 import '../frontend/skip.dart';
 import '../frontend/timeout.dart';
@@ skipping 15 matching lines @@
 
   /// Whether the test or suite should be skipped.
   final bool skip;
 
   /// Whether to use verbose stack traces.
   final bool verboseTrace;
 
   /// The reason the test or suite should be skipped, if given.
   final String skipReason;
 
+  /// A set of tags attached to a test
+  final List<String> tags;
+
   /// Platform-specific metadata.
   ///
   /// Each key identifies a platform, and its value identifies the specific
   /// metadata for that platform. These can be applied by calling [forPlatform].
   final Map<PlatformSelector, Metadata> onPlatform;
 
   /// Parses a user-provided map into the value for [onPlatform].
   static Map<PlatformSelector, Metadata> _parseOnPlatform(
       Map<String, dynamic> onPlatform) {
     if (onPlatform == null) return {};
@@ skipping 35 matching lines @@
       result[selector] = new Metadata.parse(timeout: timeout, skip: skip);
     });
     return result;
   }
 
   /// Creates new Metadata.
   ///
   /// [testOn] defaults to [PlatformSelector.all].
   Metadata({PlatformSelector testOn, Timeout timeout, bool skip: false,
           this.verboseTrace: false, this.skipReason,
-          Map<PlatformSelector, Metadata> onPlatform})
+          Map<PlatformSelector, Metadata> onPlatform, List<String> tags})
       : testOn = testOn == null ? PlatformSelector.all : testOn,
         timeout = timeout == null ? const Timeout.factor(1) : timeout,
         skip = skip,
         onPlatform = onPlatform == null
             ? const {}
-            : new UnmodifiableMapView(onPlatform);
+            : new UnmodifiableMapView(onPlatform),
+        this.tags = tags ?? const <String>[];

[nweiz, 2015/10/13 23:28:12]

Unfortunately "??" isn't usable here. Anything that gets loaded by Dartium,
which is basically everything in backend/, needs to work on an extra-wide range
of Dart versions since there's no good way to constrain the Dartium version.

[yjbanov, 2015/10/30 20:13:59]

Done.

 
   /// Creates a new Metadata, but with fields parsed from caller-friendly values
   /// where applicable.
   ///
   /// Throws a [FormatException] if any field is invalid.
   Metadata.parse({String testOn, Timeout timeout, skip,
-          this.verboseTrace: false, Map<String, dynamic> onPlatform})
+          this.verboseTrace: false, Map<String, dynamic> onPlatform,
+          List<String> tags})
       : testOn = testOn == null
             ? PlatformSelector.all
             : new PlatformSelector.parse(testOn),
         timeout = timeout == null ? const Timeout.factor(1) : timeout,
         skip = skip != null && skip != false,
         skipReason = skip is String ? skip : null,
-        onPlatform = _parseOnPlatform(onPlatform) {
+        onPlatform = _parseOnPlatform(onPlatform),
+        this.tags = tags ?? const <String>[] {
     if (skip != null && skip is! String && skip is! bool) {
       throw new ArgumentError(
           '"skip" must be a String or a bool, was "$skip".');
     }
   }
 
   /// Dezerializes the result of [Metadata.serialize] into a new [Metadata].
   Metadata.deserialize(serialized)
       : testOn = serialized['testOn'] == null
             ? PlatformSelector.all
             : new PlatformSelector.parse(serialized['testOn']),
         timeout = _deserializeTimeout(serialized['timeout']),
         skip = serialized['skip'],
         skipReason = serialized['skipReason'],
         verboseTrace = serialized['verboseTrace'],
+        tags = serialized['tags'] ?? const <String>[],
         onPlatform = new Map.fromIterable(serialized['onPlatform'],
             key: (pair) => new PlatformSelector.parse(pair.first),
             value: (pair) => new Metadata.deserialize(pair.last));
 
   /// Deserializes timeout from the format returned by [_serializeTimeout].
   static _deserializeTimeout(serialized) {
     if (serialized == 'none') return Timeout.none;
     var scaleFactor = serialized['scaleFactor'];
     if (scaleFactor != null) return new Timeout.factor(scaleFactor);
     return new Timeout(
         new Duration(microseconds: serialized['duration']));
   }
 
   /// Return a new [Metadata] that merges [this] with [other].
   ///
   /// If the two [Metadata]s have conflicting properties, [other] wins.
   Metadata merge(Metadata other) =>
       new Metadata(
           testOn: testOn.intersect(other.testOn),
           timeout: timeout.merge(other.timeout),
           skip: skip || other.skip,
           verboseTrace: verboseTrace || other.verboseTrace,
           skipReason: other.skipReason == null ? skipReason : other.skipReason,
-          onPlatform: mergeMaps(onPlatform, other.onPlatform));
+          onPlatform: mergeMaps(onPlatform, other.onPlatform),
+          tags: mergeLists(tags, other.tags));
 
   /// Returns a copy of [this] with the given fields changed.
   Metadata change({PlatformSelector testOn, Timeout timeout, bool skip,
       bool verboseTrace, String skipReason,
       Map<PlatformSelector, Metadata> onPlatform}) {
     if (testOn == null) testOn = this.testOn;
     if (timeout == null) timeout = this.timeout;
     if (skip == null) skip = this.skip;
     if (verboseTrace == null) verboseTrace = this.verboseTrace;
     if (skipReason == null) skipReason = this.skipReason;
@@ skipping 24 matching lines @@
     onPlatform.forEach((key, value) {
       serializedOnPlatform.add([key.toString(), value.serialize()]);
     });
 
     return {
       'testOn': testOn == PlatformSelector.all ? null : testOn.toString(),
       'timeout': _serializeTimeout(timeout),
       'skip': skip,
       'skipReason': skipReason,
       'verboseTrace': verboseTrace,
-      'onPlatform': serializedOnPlatform
+      'onPlatform': serializedOnPlatform,
+      'tags': tags.isEmpty ? null : tags,

[nweiz, 2015/10/13 23:28:12]

Just pass an empty list here rather than adding a special case to null it out.

[yjbanov, 2015/10/30 20:13:59]

Done.

     };
   }
 
   /// Serializes timeout into a JSON-safe object.
   _serializeTimeout(Timeout timeout) {
     if (timeout == Timeout.none) return 'none';
     return {
       'duration': timeout.duration == null
           ? null
           : timeout.duration.inMicroseconds,
       'scaleFactor': timeout.scaleFactor
     };
   }
 }