covtrim

Token-efficient coverage report compressor for LLM/agent consumption. Reads the standard lcov format and outputs a compact TSV summary — the same information in roughly half the tokens.

Install

npm install -g covtrim
# or from GitHub Packages (scoped registry to avoid dependency fetch failures)
npm config set @yanqd0:registry https://npm.pkg.github.com && npm install -g @yanqd0/covtrim
# or run without installing
npx covtrim <args>

Usage

covtrim <lcovFile>           # compress lcov → TSV summary sorted by uncovered lines
covtrim <lcovFile> --tokens  # include token-quantification stats (stderr, off by default)
covtrim node [args]          # run Node tests (auto-detected framework) → TSV
covtrim node --framework vitest  # pick the test framework explicitly
covtrim rust [args]          # run Rust tests via cargo llvm-cov → TSV
covtrim python [args]        # run Python tests via pytest-cov → TSV
covtrim deno [args]          # run Deno tests with coverage → TSV
covtrim --version            # print version
covtrim --help               # show help

⚠️ covtrim node|rust|python|deno runs the project's test/coverage commands, which executes that project's code. Only run them on repositories you trust; covtrim prints the commands it will run to stderr first.

Why

• LLMs read coverage tables poorly: they mix hundreds of test ... ok log lines with the actual table, and general-purpose token optimizers (e.g. RTK) treat the table itself as noise and drop it.
• Coverage tools emit structured output (cargo llvm-cov --json/--lcov, pytest --cov-report=lcov) but have no LLM-friendly layer on top.
• covtrim fills exactly that gap: a thin, format-agnostic layer that turns lcov into an actionable digest.

Planned features

• ✅ lcov parser (SF / LF / LH file-level counts) — implemented in 0.1.0
• ✅ Compact TSV summary sorted by uncovered lines — implemented in 0.1.0
• --diff: baseline regression detection (improved / regressed / newly-uncovered)
• --fail-under <N>: CI gate with exit code
• --summary: one-line digest for LLM context ("12 modules, 3 below 90%, needs X")
• Adapters: ✅ covtrim node (vitest / jest / c8 / mocha+nyc / bun / node:test) — 0.2.0; ✅ covtrim rust (cargo llvm-cov); ✅ covtrim python (pytest-cov); ✅ covtrim deno (built-in coverage)

Status

Active development — see the CHANGELOG for the latest release.

License

MIT