Merge pull request #43 from metatoaster/list_of_empty

Correct handling of empty/undef in list values

2 files changed, 48 insertions, 4 deletions

diff --git a/tests/test_uritemplate.py b/tests/test_uritemplate.py
index 7448be0..f67ad26 100644
--- a/tests/test_uritemplate.py
+++ b/tests/test_uritemplate.py
@@ -464,6 +464,52 @@ class TestURITemplate(RFCTemplateExamples('RFCMeta', (TestCase,), {})):
             None
         )
 
+    def test_label_path_expansion_explode_slash(self):
+        t = URITemplate('{/foo*}')
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', [], True, '/'), None
+        )
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', [None], True, '/'), None
+        )
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', [None, None], True, '/'), None
+        )
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', ['one'], True, '/'), 'one'
+        )
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', ['one', 'two'], True, '/'), 'one/two'
+        )
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', ['one', None, 'two'], True, '/'), 'one/two'
+        )
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', [''], True, '/'), ''
+        )
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', ['', ''], True, '/'), '/'
+        )
+
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', {}, True, '/'), None
+        )
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', {'one': ''}, True, '/'), 'one='
+        )
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', {'one': '', 'two': ''}, True, '/'), 'one=/two='
+        )
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', {'one': None}, True, '/'), None
+        )
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', {'one': None, 'two': 'two'}, True, '/'), 'two=two'
+        )
+        self.assertEqual(t.variables[0]._label_path_expansion(
+            'foo', {'one': None, 'two': None}, True, '/'), None
+        )
+
     def test_semi_path_expansion(self):
         t = URITemplate('{foo}')
         v = t.variables[0]
diff --git a/uritemplate/variable.py b/uritemplate/variable.py
index a3bd4ce..ce3f652 100644
--- a/uritemplate/variable.py
+++ b/uritemplate/variable.py
@@ -200,10 +200,8 @@ class URIVariable(object):
             if not explode:
                 join_str = ','
 
-            expanded = join_str.join(
-                quote(v, safe) for v in value if value is not None
-            )
-            return expanded if expanded else None
+            fragments = [quote(v, safe) for v in value if v is not None]
+            return join_str.join(fragments) if fragments else None
 
         if dict_test(value) or tuples:
             items = items or sorted(value.items())