tests: add CSV format test for v.db.select

[Abhi-d-gr8]

Added test for the format=csv code path in v.db.select. The existing testComma test covers separator=comma which doesn't quote text fields, but format=csv follows RFC 4180 and wraps text fields in double quotes (e.g. "Zwe" instead of Zwe). This test makes sure that behavior is covered.

[wenzeslaus]

Since the code is touching format == CSV code, it would be good to test that beyond the one test which is there which is looking at the values but in a way abstracts the format itself. Add a test which is in the same style as testComma, but with format="csv". Attach screenshots which show the test actually runs and also that it fails if you intentionally introduce error into the code.

Similarly, extent test is missing as far as I can tell. We can't merge these without a clear proof these are actually running.

[Abhi-d-gr8]

Hi @wenzeslaus, thanks for the detailed feedback.
I’ve added explicit test coverage for the paths you pointed out:

CSV format path: added testFormatCsv() in vector/v.db.select/testsuite/test_v_db_select.py, written in the same style as testComma, but using format="csv". This verifies the CSV-specific behavior (text fields quoted), so the format == CSV branch is now directly exercised.

Extent path: added testJSONExtent() covering -r with format=json, asserting that the output contains an extent object with numeric n/s/w/e keys.

To provide clear proof that these tests are actually running and meaningful, I’ve attached three screenshots:

1. Full testsuite run passing.
2. Testsuite run failing after intentionally introducing a regression (changing extent key n → x).
3. The failure details showing the assertion triggered by the regression.
   This should demonstrate that both the CSV and extent code paths are covered and that the tests correctly detect breakage.

Let me know if you’d like an additional extent test for another output format as well.

[petrasovaa]

Hi @Abhi-d-gr8, this is a good PR, but in the end I decided to go with #7076. I was thinking we could still merge the CSV test though, if you update your PR to contain just that.
Thanks for your understanding!

[Abhi-d-gr8]

Hi @petrasovaa !,
Thanks for the feedback! I've updated the PR to contain just the CSV format test. The branch is now rebased on latest main (which includes #7076) and contains only a single test commit.
Also updating the title and description accordingly...
.

[petrasovaa]

Sorry for the delay, I think this is good to go.

Addressed