Status: IN
Tests appear in two coexisting patterns — inline unittest classes within solution.py and separate test_solution.py files — but the antecedents show these are complementary rather than incompatible: some problems use both, with the separate test file being the consistent convention and inline tests being an optional addition. No evidence indicates a conflict between the patterns or that the lack of a single enforced standard causes problems.
Both test patterns work but the inconsistency reflects the same isolation-driven style drift as the class-vs-function split
Depends on (SL): tests-colocated-in-solution-file, test-files-import-sibling-solution, some-solutions-bundle-tests-inline, repo-solution-test-convention