Refs django#10941 -- Added tests in querystring template tag.

These extra tests assert over the handling of empty params (None, empty
dict, empty QueryDict), and also for dicts having non-string keys.

tests/template_tests/syntax_tests/test_querystring.py

@@ -13,23 +13,38 @@ def assertRenderEqual(self, template_name, context, expected):
         output = self.engine.render_to_string(template_name, context)
         self.assertEqual(output, expected)
 
-    @setup({"querystring_empty": "{% querystring %}"})
-    def test_querystring_empty(self):
+    @setup({"test_querystring_empty_get_params": "{% querystring %}"})
+    def test_querystring_empty_get_params(self):
         context = RequestContext(self.request_factory.get("/"))
-        self.assertRenderEqual("querystring_empty", context, expected="")
+        self.assertRenderEqual(
+            "test_querystring_empty_get_params", context, expected=""
+        )
 
-    @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"})
         context = RequestContext(request)
-        self.assertRenderEqual("querystring_non_empty", context, expected="?a=b")
+        self.assertRenderEqual(
+            "test_querystring_non_empty_get_params", context, expected="?a=b"
+        )
 
     @setup({"querystring_multiple": "{% querystring %}"})
     def test_querystring_multiple(self):
         request = self.request_factory.get("/", {"x": "y", "a": "b"})
         context = RequestContext(request)
         self.assertRenderEqual("querystring_multiple", context, expected="?x=y&a=b")
 
+    @setup({"test_querystring_empty_params": "{% querystring qd %}"})
+    def test_querystring_empty_params(self):
+        cases = [None, {}, QueryDict()]
+        request = self.request_factory.get("/")
+        for param in cases:
+            with self.subTest(param=param):
+                context = RequestContext(request, {"qd": param})
+                self.assertRenderEqual(
+                    "test_querystring_empty_params", context, expected=""
+                )
+
     @setup({"querystring_replace": "{% querystring a=1 %}"})
     def test_querystring_replace(self):
         request = self.request_factory.get("/", {"x": "y", "a": "b"})
@@ -64,6 +79,14 @@ def test_querystring_add_list(self):
         context = RequestContext(request, {"my_list": [2, 3]})
         self.assertRenderEqual("querystring_list", context, expected="?a=2&a=3")
 
+    @setup({"querystring_dict": "{% querystring a=my_dict %}"})
+    def test_querystring_add_dict(self):
+        request = self.request_factory.get("/")
+        context = RequestContext(request, {"my_dict": {i: i * 2 for i in range(3)}})
+        self.assertRenderEqual(
+            "querystring_dict", context, expected="?a=0&a=1&a=2"
+        )
+
     @setup({"querystring_query_dict": "{% querystring request.GET a=2 %}"})
     def test_querystring_with_explicit_query_dict(self):
         request = self.request_factory.get("/", {"a": 1})