When writing tests, prioritize coverage of edge cases and non-standard code patterns to ensure robust functionality. Particularly for linting rules or code transformations, identify scenarios that might behave unexpectedly or require special handling. Include tests for: - Code with comments in various positions - Unusual formatting or line continuations - Nested object constructions - Dependencies on multiple variables - Different parameter passing styles (positional vs. keyword) For example, when testing a rule that transforms string paths to Path objects: ```python # Test with comments in different positions func_name( # comment "filename") func_name( # comment "filename", #comment ) # Test with line continuations func_name \ \ ( # comment "filename", ) # Test with nested objects func_name(Path("filename").resolve()) # Test with dependencies on other variables for x, y in some_pairs: result.add((x, y)) ``` Testing these edge cases early prevents subtle bugs from surfacing in production code and makes your code more maintainable over time.