pkg/matcher: add isNaN and isNotNaN matchers

pkg/matcher/lib/src/core_matchers.dart

Index: pkg/matcher/lib/src/core_matchers.dart
diff --git a/pkg/matcher/lib/src/core_matchers.dart b/pkg/matcher/lib/src/core_matchers.dart
index 356476b24d0f33d49d373f6ef7bb4ad7a4f3cba2..e33177cf6380f6b6bb91e88e3e52aa30203a7c27 100644
--- a/pkg/matcher/lib/src/core_matchers.dart
+++ b/pkg/matcher/lib/src/core_matchers.dart
@@ -64,6 +64,24 @@ class _IsFalse extends Matcher {
   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 == NaN;

[kevmoo, 2014/07/22 20:44:37]

Where is NaN coming from here? Do you mean double.NAN?

[srawlins, 2014/07/22 22:49:06]

Done.

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

[kevmoo, 2014/07/22 20:44:37]

ditto

[srawlins, 2014/07/22 22:49:06]

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);