tests: retire correctness/regression tests covered by C++ gtests

[ramakrishnap-nv]

Remove 5 Python tests that assert specific solver output values. The Python test suite should cover API behavior; correctness and regression coverage for these cases already exists in the C++ gtest suite.

Removed tests:

• test_qp.py::test_solver — asserted QP objective −32 and variable values x1=4, x2=2. QP correctness covered by cpp/tests/linear_programming/qp_test.cu; QP API covered by test_python_API.py::test_quadratic_objective_* tests.
• test_solver.py::test_solomon — asserted VRPTW objective ~1087.15 and vehicle count ≤12. Routing API covered by test_vehicle_properties.py.
• test_solver.py::test_pdptw — asserted PDP objective 13.0. Pickup-delivery pairs API covered by test_vehicle_properties.py::test_heterogenous_breaks.
• test_distance_engine.py::test_compute_cost_matrix — numerical matrix match against reference CSVs. compute_cost_matrix API covered by the kept test_compute_waypoint_sequence_* tests.
• test_distance_engine.py::test_compute_shortest_path_costs — exact matrix match against hardcoded expected values. Error-path coverage for compute_shortest_path_costs retained in test_target_locations_validity.

Also removes helper functions and imports that were only used by the deleted tests.

[coderabbitai]

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📥 Commits

Reviewing files that changed from the base of the PR and between caa7835 and 1d66a5f.

📒 Files selected for processing (2)

• python/cuopt/cuopt/tests/linear_programming/test_incumbent_callbacks.py
• python/cuopt/cuopt/tests/socp/test_socp.py

💤 Files with no reviewable changes (2)

• python/cuopt/cuopt/tests/linear_programming/test_incumbent_callbacks.py
• python/cuopt/cuopt/tests/socp/test_socp.py

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📝 Walkthrough

Walkthrough

The PR removes one quadratic-programming test module and prunes several routing, callback, and SOCP test cases. It also simplifies imports in the affected routing test files.

Changes

Routing test pruning

Layer / File(s)	Summary
Distance-engine shortest-path tests python/cuopt/cuopt/tests/routing/test_distance_engine.py	The import block drops pandas and cuopt.routing.utils, and the shortest-path helper plus test_compute_shortest_path_costs() are removed.
Routing solver cases python/cuopt/cuopt/tests/routing/test_solver.py	The import block drops os, math, and cuopt.routing.utils, and test_solomon plus test_pdptw are removed before test_prize_collection.

Incumbent callback inputs

Layer / File(s)	Summary
Callback parameter lists python/cuopt/cuopt/tests/linear_programming/test_incumbent_callbacks.py	Both incumbent-callback tests remove /mip/swath1.mps from their parametrized input lists.

SOCP regression pruning

Layer / File(s)	Summary
SOCP 1 barrier test python/cuopt/cuopt/tests/socp/test_socp.py	The module deletes the socp_1 expected constants, the build_socp_1() helper, and test_socp_1_barrier_solution().
Unsymmetric quadratic test python/cuopt/cuopt/tests/socp/test_socp.py	The module removes test_general_quadratic_unsymmetric().

Estimated code review effort: 2 (Simple) | ~10 minutes

Suggested reviewers: mlubin, Iroy30

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly summarizes the main change: removing Python regression tests in favor of C++ gtest coverage.
Description check	✅ Passed	The description matches the changeset by describing removal of Python tests and their replacement coverage in C++ gtests.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch ci/retire-correctness-regression-tests

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[github-actions]

🔔 Hi @anandhkb @ramakrishnap-nv, this pull request has had no activity for 7 days. Please update or let us know if it can be closed. Thank you!

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[github-actions]

🔔 Hi @anandhkb @ramakrishnap-nv, this pull request has had no activity for 7 days. Please update or let us know if it can be closed. Thank you!

If this is an "epic" issue, then please add the "epic" label to this issue.
If it is a PR and not ready for review, then please convert this to draft.
If you just want to switch off this notification, then use the "skip inactivity reminder" label.

[Iroy30]

Thanks!

[ramakrishnap-nv]

/ok to test 04fbd46

[github-actions]

CI Test Summary

✅ All 22 test job(s) passed.

[ramakrishnap-nv]

/merge