wscalls: preview unflattened payload (#66916)

tests/api/test_all.py

@@ -284,7 +284,7 @@ def test_preview_json_payload(pub, admin_user):
 
     assert resp.pyquery('div.payload-preview').length == 1
     assert '<h2>Payload preview</h2>' in resp.text
-    resp.pyquery('div.payload-preview').text() == '{}'
+    assert resp.pyquery('div.payload-preview').text() == '{}'
     params = {
         'request$post_data$added_elements': 1,
         'request$post_data$element1key': 'user/first_name',
@@ -296,7 +296,7 @@ def test_preview_json_payload(pub, admin_user):
         'request$post_data$element3key': 'user/0',
     }
     resp = app.get('/api/preview-json-payload', params=params)
-    resp.pyquery('div.payload-preview div.errornotice').length == 0
+    assert resp.pyquery('div.payload-preview div.errornotice').length == 0
     assert resp.pyquery('div.payload-preview').text() == '{"user": {"first_name": "Foo","last_name": "Bar",}}'
 
     params.update(