R23-T051: Hypothesis property tests and boundary doctests for points_are_collinear_3d - #61

Description

Adds Hypothesis property-based tests for maths/points_are_collinear_3d.py and new doctests for nearly-collinear points. The property tests check that B = A + t·v and C = A + s·v are always collinear, and that points moved off the line are not. The doctests document how the accuracy rounding decides the result near the boundary.

Related Issue

Fixes: #6

Type of Change

• Bug Fix
• New Feature
• UI/UX Improvement
• Performance Improvement
• Tests
• Documentation
• Refactoring / Maintenance
• CI/CD

Changes Made

• Added work/R23-T051/test_points_are_collinear_3d_properties.py with 3 Hypothesis tests (2000 examples each): exact integer collinearity, float collinearity (accuracy=6), and perturbed points not collinear.
• Added work/R23-T051/PROPERTIES.md explaining each property and the findings.
• Added 4 doctests to are_collinear in maths/points_are_collinear_3d.py for nearly-collinear points at different accuracy values.

Screenshots / Recordings

Not applicable (no UI changes).

Testing

• python -m pytest work/R23-T051/ -v -> 3 passed
• python -m doctest -v maths/points_are_collinear_3d.py -> 18 passed (14 existing + 4 new)
• python -m pytest --doctest-modules maths/points_are_collinear_3d.py -> passed
• ruff check maths/points_are_collinear_3d.py -> all checks passed

Checklist

• I have tested my changes locally.
• I have added or updated tests, if needed.
• I have updated documentation, if needed.
• I have followed the project's coding guidelines.
• I have run the relevant tests and checks.
• I have addressed previous review feedback, if applicable.

Additional Notes

Findings: Hypothesis found no failing inputs. The result depends on accuracy, e.g. (0,0,0), (1,0,0), (2,1e-6,0) is False at accuracy=10 but True at accuracy=5. The check uses an absolute tolerance, so very large or very small coordinates can be misjudged. See work/R23-T051/PROPERTIES.md.