Add isNotEmpty to core_matchers.

pkg/matcher/test/matchers_minified_test.dart

Index: pkg/matcher/test/matchers_minified_test.dart
diff --git a/pkg/matcher/test/matchers_minified_test.dart b/pkg/matcher/test/matchers_minified_test.dart
index 65a35ac3bfe5dd2124849ada0845992bc2885466..4b39d427378a7509d13828403a8f871449f80505 100644
--- a/pkg/matcher/test/matchers_minified_test.dart
+++ b/pkg/matcher/test/matchers_minified_test.dart
@@ -109,6 +109,14 @@ void main() {
           matches(r"Expected: empty +Actual: " + _MINIFIED_NAME + r":\[1\]"));
     });
 
+    test('isNotEmpty', () {
+      var d = new SimpleIterable(0);
+      var e = new SimpleIterable(1);
+      shouldPass(e, isNotEmpty);
+      shouldFail(d, isNotEmpty,
+          matches(r"Expected: non-empty +Actual: " + _MINIFIED_NAME + r":\[\]"));

[Lasse Reichstein Nielsen, 2014/11/27 15:22:46]

Long line.
The first part of the string doesn't have to be raw, so you could interpolate
the minified name into that.

[blackhc, 2014/11/28 16:12:29]

There are 10 matches in the unit tests for this kind of string concatenation and
I think it would be better to change them all at once instead of introducing an
inconsistency here. I'm not sure this CL is the best place to do that. What do
you think?

+    });
+
     test('contains', () {
       var d = new SimpleIterable(3);
       shouldPass(d, contains(2));