query_string cannot use variables as keys

[Sarah Boyce]

Raised by Florian here: ​https://forum.djangoproject.com/t/adding-a-template-tag-to-generate-query-strings/24521/15

If we are to add a test:

tests/template_tests/syntax_tests/test_query_string.py

@@ -98 +98 @@
         msg = "'Context' object has no attribute 'request'"
         with self.assertRaisesMessage(AttributeError, msg):
             self.engine.render_to_string("query_string_no_request_no_query_dict")
+
+    @setup(
+        {
+            "query_string_var_key": '{% with key="var_key" %}{% query_string key=2 %}'
+            "{% endwith %}"
+        }
+    )
+    def test_query_string_with_variable_key(self):
+        request = self.request_factory.get("/")
+        template = self.engine.get_template("query_string_var_key")
+        context = RequestContext(request)
+        output = template.render(context)
+        self.assertEqual(output, "?var_key=2")

This fails with AssertionError: '?key=2' != '?var_key=2'.

One suggestion is to quote literal keys eg. {% query_string var_key=1 'other_key'=2 %}

Refs #10941, design decision required, potential release blocker

[Carsten Fuchs]

This is one of the reasons why my original code supported dictionaries for input.
See the last example at https://code.djangoproject.com/ticket/10941#comment:33, repeated here for reference:

{# Overwrite month and year with precomputed values, e.g. with next_month_year = {'month': 1, 'year': 2022}, and clear the day: #}
{% query_string request.GET next_month_year day=None %}

[Sarah Boyce]

Based off the conclusion in the discussion