pkg/matcher: add isNaN and isNotNaN matchers

pkg/matcher/lib/src/core_matchers.dart

 // Copyright (c) 2012, 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 matcher.core_matchers;
 
 import 'dart:async';
 
 import 'description.dart';
 import 'expect.dart';
@@ skipping 46 matching lines @@
   bool matches(item, Map matchState) => item == true;
   Description describe(Description description) => description.add('true');
 }
 
 class _IsFalse extends Matcher {
   const _IsFalse();
   bool matches(item, Map matchState) => item == false;
   Description describe(Description description) => description.add('false');
 }
 
+/// A matcher that matches the numeric value NaN.
+const Matcher isNaN = const _IsNull();
+
+/// A matcher that matches any non-NaN value.
+const Matcher isNotNaN = const _IsNotNaN();
+
+class _IsNaN extends Matcher {
+  const _IsNaN();
+  bool matches(item, Map matchState) => item == double.NaN;

[kevmoo, 2014/07/25 18:21:08]

double.NAN

Are you running tests locally before updating the CL?

[srawlins, 2014/07/30 17:08:03]

Sorry, I was _not_ running the correct set of tests; there was a flaw in this
implementation, and I've replaced my use of == with double.NAN.compareTo().
Thanks Kevin!!!

+  Description describe(Description description) => description.add('NaN');
+}
+
+class _IsNotNaN extends Matcher {
+  const _IsNotNaN();
+  bool matches(item, Map matchState) => item != double.NaN;

[kevmoo, 2014/07/25 18:21:08]

ditto

[srawlins, 2014/07/30 17:08:03]

Done.

+  Description describe(Description description) => description.add('not NaN');
+}
+
 /// Returns a matches that matches if the value is the same instance
 /// as [expected], using [identical].
 Matcher same(expected) => new _IsSameAs(expected);
 
 class _IsSameAs extends Matcher {
   final _expected;
   const _IsSameAs(this._expected);
   bool matches(item, Map matchState) => identical(item, _expected);
   // If all types were hashable we could show a hash here.
   Description describe(Description description) =>
@@ skipping 643 matching lines @@
         addDescriptionOf(matchState['feature']);
     var innerDescription = new StringDescription();
     _matcher.describeMismatch(matchState['feature'], innerDescription,
         matchState['state'], verbose);
     if (innerDescription.length > 0) {
       mismatchDescription.add(' which ').add(innerDescription.toString());
     }
     return mismatchDescription;
   }
 }