test: fix compression-size assertions on too-small inputs#2
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`test_enhanced_ctw_basic` and `test_multi_pass_basic` asserted `compressed.len() < test_data.len()` on inputs so small that stream framing overhead made the check fail against a correct implementation. - enhanced_ctw: repeat the 58-byte input 32x so the zstd header is amortized and the compression-ratio assertion is meaningful. - multi_pass: switch to input with immediately-adjacent doubled 4-byte blocks so `apply_pattern_replacement` can actually compress on the first pass (matching `data[pos..pos+4] == data[pos+4..pos+8]`). Both roundtrip / size-reduction invariants now hold. All 25 tests pass.
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Summary
Two unit tests on
mainfail on a cleancargo test --features zstd:Both failed on the same assertion shape (
compressed.len() < test_data.len()) against inputs too small / too non-repetitive for the algorithm's framing overhead to pay for itself. The underlying implementations are correct -- the tests themselves were wrong.Fix
test_enhanced_ctw_basic: repeat the 58-byte input 32x so the zstd header is amortized and the ratio assertion is meaningful. Roundtrip assertion unchanged.test_multi_pass_basic: switch to input with immediately-adjacent doubled 4-byte blocks (AAAAAAAABBBBBBBB...) soapply_pattern_replacementcan actually compress on the first pass -- the previousAAAA BBBB CCCC ...input never matched thedata[pos..pos+4] == data[pos+4..pos+8]pattern and returned the original bytes unchanged.Test suite before:
23 passed, 2 failedTest suite after:
25 passed, 0 failedScope: 2 files, +25 -6 lines, tests only. No behavior changes to library code.
closes #1
Contributed by kcolbchain (https://kcolbchain.com) · https://abhishekkrishna.com