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Backend bails out when submitting query without data source: `KeyError: 'datasource'`

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Assessment

Difficulty
2/5
Estimated time
1-3 hours
Newbie friendliness
65/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Active
Tech stack
python
Domain
api, backend

Research direction

Start in patzilla/navigator/services/util.py, at query_expression_util_handler and make_expression_filter, where the traceback shows the missing 'datasource' key is accessed. Trace how the query request is validated and handled when no data source is selected, then add or update a focused test for that request. Done when submitting such a query no longer causes a backend KeyError.

Written by the indexing model from the issue text.

Description

Problem

Navigating around wildly, I have been able to submit a query without selecting a data source, which currently makes the backend bail out.

Details

2026-10-27 13:49:04,182 ERROR    [waitress                                ][waitress-2] Exception while serving /api/util/query-expression
Traceback (most recent call last):
  File "/path/to/site-packages/waitress/channel.py", line 430, in service
    task.service()
    ~~~~~~~~~~~~^^
  File "/path/to/site-packages/waitress/task.py", line 167, in service
    self.execute()
    ~~~~~~~~~~~~^^
  File "/path/to/site-packages/waitress/task.py", line 435, in execute
    app_iter = self.channel.server.application(environ, start_response)
  File "/path/to/site-packages/waitress/proxy_headers.py", line 64, in translate_proxy_headers
    return app(environ, start_response)
  File "/path/to/site-packages/paste/deploy/config.py", line 306, in __call__
    return self.app(environ, start_response)
           ~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/path/to/site-packages/pyramid/router.py", line 274, in __call__
    response = self.execution_policy(environ, self)
  File "/path/to/site-packages/pyramid/router.py", line 283, in default_execution_policy
    return request.invoke_exception_view(reraise=True)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^
  File "/path/to/site-packages/pyramid/view.py", line 787, in invoke_exception_view
    reraise_(*exc_info)
    ~~~~~~~~^^^^^^^^^^^
  File "/path/to/site-packages/pyramid/_compat.py", line 178, in reraise
    raise value.with_traceback(tb)
  File "/path/to/site-packages/pyramid/router.py", line 281, in default_execution_policy
    return router.invoke_request(request)
           ~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^
  File "/path/to/site-packages/pyramid/router.py", line 249, in invoke_request
    response = handle_request(request)
  File "/path/to/site-packages/pyramid/tweens.py", line 43, in excview_tween
    response = _error_handler(request, exc)
  File "/path/to/site-packages/pyramid/tweens.py", line 13, in _error_handler
    response = request.invoke_exception_view(exc_info)
  File "/path/to/site-packages/pyramid/view.py", line 774, in invoke_exception_view
    response = _call_view(
        registry,
    ...<7 lines>...
        request_iface=request_iface.combined,
    )
  File "/path/to/site-packages/pyramid/view.py", line 683, in _call_view
    response = view_callable(context, request)
  File "/path/to/site-packages/pyramid/viewderivers.py", line 401, in viewresult_to_response
    result = view(context, request)
  File "/path/to/site-packages/pyramid/tweens.py", line 41, in excview_tween
    response = handler(request)
  File "/path/to/site-packages/pyramid/router.py", line 147, in handle_request
    response = _call_view(
        registry, request, context, context_iface, view_name
    )
  File "/path/to/site-packages/pyramid/view.py", line 683, in _call_view
    response = view_callable(context, request)
  File "/path/to/site-packages/pyramid/config/views.py", line 169, in __call__
    return view(context, request)
  File "/path/to/site-packages/pyramid/config/views.py", line 188, in attr_view
    return view(context, request)
  File "/path/to/site-packages/pyramid/config/views.py", line 214, in predicate_wrapper
    return view(context, request)
  File "/path/to/site-packages/pyramid/viewderivers.py", line 436, in rendered_view
    result = view(context, request)
  File "/path/to/site-packages/pyramid/viewderivers.py", line 144, in _requestonly_view
    response = view(request)
  File "/path/to/site-packages/cornice/service.py", line 493, in wrapper
    response = view_(request)
  File "/path/to/patzilla/patzilla/navigator/services/util.py", line 60, in query_expression_util_handler
    expression_data = make_expression_filter(data)
  File "/path/to/patzilla/patzilla/navigator/services/util.py", line 69, in make_expression_filter
    datasource = data['datasource']
                 ~~~~^^^^^^^^^^^^^^
KeyError: 'datasource'
Dominant language
Python
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Forks
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Avg merge
1h 6m
Merged PRs (30d)
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