Config¶

Every key .mutation-gate.toml accepts. An unknown top-level, languages.* or [[golden]] key is a GateError at load time.

A starting file¶

An empty .mutation-gate.toml works: every key below has a default. A typical Python repo with tests in Docker:

test_paths = ["tests"]
test_command = 'docker run --rm -u "$(id -u):$(id -g)" -v "$PWD":/repo -w /repo my-image python -m pytest -q {tests}'
exclude_paths = ["vendor/"]

[[doc_allow]]
glob = "docs/**/*"
reason = "mkdocs site content"

A repo with model code:

model_paths = ["filters/"]
model_spec = "issue:19"
model_test_paths = ["tests/filters/"]

A repo gating two languages:

[languages.python]
test_paths = ["tests"]
test_command = "python -m pytest -q {tests}"

[languages.typescript]
test_paths = ["web/tests"]
test_command = "npm --prefix web run test"

Each table overrides test_paths, test_globs, test_command, coverage_command and coverage_data_file for that language.
.tsx files are their own language, tsx, and need their own table.

Keys¶

Key	Default	What it does
`enabled`	`true`	Opts this repo out of the gate entirely when `false`.
`language`	`"python"`	Language the flat fields below describe.
`test_paths`	`["tests"]`	Repo-root-relative directories; everything under them counts as a test.
`test_globs`	`[]`	`Path.glob` patterns for tests that sit beside their sources, not under `test_paths`.
`test_command`	`"pytest -q {tests}"`	Shell command that runs the tests; `{tests}` is the full candidate set for the baseline run, or the covering test ids per mutant, falling back to the full set.
`coverage_command`	`"pytest -q --cov={file} --cov-context=test --cov-report= {tests}"`	Shell command that runs the candidate tests under coverage; `{file}` is the mutated file's containing directory, not the file itself.
`coverage_data_file`	`".coverage"`	Where the coverage command writes its data; read per line to map which tests cover the mutated file.
`languages`	`{}`	`[languages.<name>]` tables, each a `test_paths`/`test_globs`/`test_command`/`coverage_command`/`coverage_data_file` override, for a repo gating more than one language.
`exclude_paths`	`[]`	Path prefixes the gate never touches; announced on every skip.
`model_paths`	`[]`	Path prefixes in scope for model V&V, declared, never inferred; `rules sync` also builds `model-vv.md`'s `paths:` frontmatter from this.
`model_spec`	`"docs/model-spec.md"`	Where the model spec's `MS-n` lines live: `issue:N`, a GitHub issue. Required once `model_paths` is set; a file path, including this default, is refused there.
`model_test_paths`	`[]`	Test paths that must cite an `MS-n` spec line.
`model_exclude`	`[]`	`[[model_exclude]]` entries, each a `path` and a `reason`: a keyword-probe hit outside `model_paths` that isn't model code.
`golden`	`[]`	`[[golden]]` entries, each a `source` and an `artifact`: a generated F/Q artefact and the SymPy source its hash is checked against.
`pass_pattern`	`""`	Regex the test output must contain to count as green; empty trusts the exit code.
`force_gate`	`false`	Gates a fork or an out-of-namespace checkout anyway.
`baseline_timeout`	`900.0`	Seconds allowed for the unmutated baseline run, and for the coverage run that maps tests to lines.
`mutant_timeout`	none (derived from the baseline)	Seconds allowed per mutant, when the derived cap is wrong.
`closure_depth`	`1`	Import hops from a test to the mutated file that still count as covering it.
`import_roots`	`[]`	Extra repo-root-relative import roots for a src layout with no `sys.path.insert` in the test files.
`no_comments`	`false`	Blocks on a comment line the diff added.
`vocabulary`	`""`	Path to the repo's own vocabulary file, layered over the packaged core dictionary; empty turns the gate's vocabulary checks off, and `vocabulary lookup` uses the core dictionary alone.
`vocabulary_molds`	`{}`	Per-kind naming molds `vocabulary lookup --kind` checks names against; narrows the built-in set, never widens.
`vocabulary_synonyms`	`"report"`	`"report"` prints a WordNet-synonym collision on a dictionary addition as a report line; `"block"` fails it.
`own_namespaces`	`[]`	Origin substrings this checkout is allowed to gate under; outside all of them reads as a fork. The `MUTATION_GATE_OWN_NAMESPACES` env var overrides this when set.
`doc_allow`	`[]`	`[[doc_allow]]` entries, each a `glob` and a `reason`: a new `.md` file the built-in allowlist doesn't cover.
`banned_names_file`	`""`	Path to a file of `X → Y` lines `no-leaks` must reject from the staged diff and commit message.

Source: mutation_gate/repo.py.