improve .dist-info test

--HG--
branch : distribute
extra : rebase_source : 23b6b4023d413bf1b27b114687da8736a4b38d8b

setuptools/tests/test_dist_info.py

@@ -3,6 +3,11 @@
 import os, shutil, tempfile, unittest
 import pkg_resources
 from pkg_resources import Requirement
+try:
+    import markerlib
+    has_markerlib = True
+except:
+    has_markerlib = False
 
 class TestDistInfo(unittest.TestCase):
 
@@ -11,19 +16,24 @@ class TestDistInfo(unittest.TestCase):
         for d in pkg_resources.find_distributions(self.tmpdir):
             dists[d.project_name] = d
             
+        assert len(dists) == 2, dists
+            
         unversioned = dists['UnversionedDistribution']
         versioned = dists['VersionedDistribution']
         
         assert versioned.version == '2.718' # from filename        
         assert unversioned.version == '0.3' # from METADATA
-        
+                
+    @unittest.skipIf(not has_markerlib, 
+                     "install markerlib to test conditional dependencies") 
+    def test_conditional_dependencies(self):
         requires = [Requirement.parse('splort==4'), 
                     Requirement.parse('quux>=1.1')]
         
-        for d in (unversioned, versioned):
+        for d in pkg_resources.find_distributions(self.tmpdir):
             self.assertEquals(d.requires(), requires[:1])
             self.assertEquals(d.requires(extras=('baz',)), requires)
-            self.assertEquals(d.extras, ['baz'])
+            self.assertEquals(d.extras, ['baz'])        
 
     def setUp(self):
         self.tmpdir = tempfile.mkdtemp()