Refs django#10941 -- Added tests for querystring template tag to hand…

…le empty params.

tests/template_tests/syntax_tests/test_querystring.py

@@ -6,71 +6,77 @@
 
 
 class QueryStringTagTests(SimpleTestCase):
-    def setUp(self):
-        self.request_factory = RequestFactory()
-
-    @setup({"querystring_empty": "{% querystring %}"})
-    def test_querystring_empty(self):
-        request = self.request_factory.get("/")
-        template = self.engine.get_template("querystring_empty")
-        context = RequestContext(request)
-        output = template.render(context)
+
+    request_factory = RequestFactory()
+
+    def assertRenderEqual(self, template_name, request=None, **context):
+        if request is None:
+            request = self.request_factory.get("/")
+        template = self.engine.get_template(template_name)
+        context = RequestContext(request, context)
+        return template.render(context)
+
+    @setup({"test_querystring_empty_get_params": "{% querystring %}"})
+    def test_querystring_empty_get_params(self):
+        output = self.assertRenderEqual("test_querystring_empty_get_params")
         self.assertEqual(output, "")
 
-    @setup({"querystring_non_empty": "{% querystring %}"})
-    def test_querystring_non_empty(self):
+    @setup({"test_querystring_non_empty_get_params": "{% querystring %}"})
+    def test_querystring_non_empty_get_params(self):
         request = self.request_factory.get("/", {"a": "b"})
-        template = self.engine.get_template("querystring_non_empty")
-        context = RequestContext(request)
-        output = template.render(context)
+        output = self.assertRenderEqual(
+            "test_querystring_non_empty_get_params", request
+        )
         self.assertEqual(output, "?a=b")
 
+    @setup({"test_querystring_empty_params": "{% querystring qd %}"})
+    def test_querystring_empty_params(self):
+        cases = [None, {}, QueryDict()]
+        for param in cases:
+            with self.subTest(param=param):
+                output = self.assertRenderEqual(
+                    "test_querystring_empty_params", qd=param
+                )
+                self.assertEqual(output, "")
+
+    @setup({"test_querystring_empty_dict": "{% querystring qd %}"})
+    def test_querystring_empty_dict(self):
+        output = self.assertRenderEqual("test_querystring_empty_dict", qd={})
+        self.assertEqual(output, "")
+
     @setup({"querystring_multiple": "{% querystring %}"})
     def test_querystring_multiple(self):
         request = self.request_factory.get("/", {"x": "y", "a": "b"})
-        template = self.engine.get_template("querystring_multiple")
-        context = RequestContext(request)
-        output = template.render(context)
+        output = self.assertRenderEqual("querystring_multiple", request)
         self.assertEqual(output, "?x=y&a=b")
 
     @setup({"querystring_replace": "{% querystring a=1 %}"})
     def test_querystring_replace(self):
         request = self.request_factory.get("/", {"x": "y", "a": "b"})
-        template = self.engine.get_template("querystring_replace")
-        context = RequestContext(request)
-        output = template.render(context)
+        output = self.assertRenderEqual("querystring_replace", request)
         self.assertEqual(output, "?x=y&a=1")
 
     @setup({"querystring_add": "{% querystring test_new='something' %}"})
     def test_querystring_add(self):
         request = self.request_factory.get("/", {"a": "b"})
-        template = self.engine.get_template("querystring_add")
-        context = RequestContext(request)
-        output = template.render(context)
+        output = self.assertRenderEqual("querystring_add", request)
         self.assertEqual(output, "?a=b&test_new=something")
 
     @setup({"querystring_remove": "{% querystring test=None a=1 %}"})
     def test_querystring_remove(self):
         request = self.request_factory.get("/", {"test": "value", "a": "1"})
-        template = self.engine.get_template("querystring_remove")
-        context = RequestContext(request)
-        output = template.render(context)
+        output = self.assertRenderEqual("querystring_remove", request)
         self.assertEqual(output, "?a=1")
 
     @setup({"querystring_remove_nonexistent": "{% querystring nonexistent=None a=1 %}"})
     def test_querystring_remove_nonexistent(self):
         request = self.request_factory.get("/", {"x": "y", "a": "1"})
-        template = self.engine.get_template("querystring_remove_nonexistent")
-        context = RequestContext(request)
-        output = template.render(context)
+        output = self.assertRenderEqual("querystring_remove_nonexistent", request)
         self.assertEqual(output, "?x=y&a=1")
 
     @setup({"querystring_list": "{% querystring a=my_list %}"})
     def test_querystring_add_list(self):
-        request = self.request_factory.get("/")
-        template = self.engine.get_template("querystring_list")
-        context = RequestContext(request, {"my_list": [2, 3]})
-        output = template.render(context)
+        output = self.assertRenderEqual("querystring_list", my_list=[2, 3])
         self.assertEqual(output, "?a=2&a=3")
 
     @setup({"querystring_query_dict": "{% querystring request.GET a=2 %}"})