[ENH] tests(lookup): isolate lookup tests to dedicated mock package

[arnavk23]

Reference Issues/PRs

Fixes #114.

What does this implement/fix? Explain your changes.

Isolate the lookup tests from the main package by introducing a dedicated test-only package skbase.tests.mock_package. The lookup tests now scan this small controlled package instead of skbase, preventing unrelated production refactors from breaking lookup tests.

Does your contribution introduce a new dependency? If yes, which one?

What should a reviewer concentrate their feedback on?

Any other comments?

PR checklist

For all contributions

• I've reviewed the project documentation on contributing
• I've added myself to the list of contributors.
• The PR title starts with either [ENH], [CI/CD], [MNT], [DOC], or [BUG] indicating whether
  the PR topic is related to enhancement, CI/CD, maintenance, documentation, or a bug.

For code contributions

• Unit tests have been added covering code functionality
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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 83.65%. Comparing base (306958d) to head (46e0a8b).
⚠️ Report is 177 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #476      +/-   ##
==========================================
- Coverage   85.07%   83.65%   -1.43%     
==========================================
  Files          45       52       +7     
  Lines        3015     3848     +833     
==========================================
+ Hits         2565     3219     +654     
- Misses        450      629     +179     

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[fkiraly]

Great!

There is though an entire config file which checks expectations against actuals after retrieval.

I would expect that still to happen for the mock package, but it does not - are you sure you have moved all tests over? I would at least expect the "full package expected lookup results" to be removed.

[arnavk23]

I would at least expect the "full package expected lookup results" to be removed.

I've removed the "full package expected lookup results" from conftest.py eliminating the SKBASE_*_BY_MODULE dictionaries that contained the expected classes and functions for the entire skbase package. I also removed the test function test_get_package_metadata_returns_expected_results that relied on those expected results, as it was checking the full package lookup against predefined expectations.

The checks for the mock package still occur through the existing tests:

• test_all_objects_returns_expected_output verifies that all_objects returns the expected classes from MOCK_PACKAGE_OBJECTS for the mock package.
• test_get_package_metadata_matches_expected_representation_mock_package builds expected metadata by introspecting the mock package modules and compares it against the actual results from get_package_metadata.

This ensures that expectation checks against actual retrieval still happen for the mock package, while restricting the lookup tests by removing the broader full-package validation.