Add regression test for query form action

tests/test_query_form_action.py

@@ -0,0 +1,12 @@
+import pytest
+from bs4 import BeautifulSoup as Soup
+
+
+@pytest.mark.asyncio
+async def test_ad_hoc_query_form_posts_to_query_route(ds_client):
+    response = await ds_client.get("/fixtures/-/query?sql=select+1")
+    assert response.status_code == 200
+
+    form = Soup(response.text, "html.parser").select_one("form.sql.core")
+    assert form is not None
+    assert form["action"] == "/fixtures/-/query"