fix: print the display name in compact output, not the config key - #529

Fixes #528.

What

The same failing check is named two ways depending on the format:

$ echo "docs: revamped the profile" | commit-check -m --subject-imperative=true --no-banner
CC003 subject-imperative check failed ==> docs: revamped the profile

$ echo "docs: revamped the profile" | commit-check -m --subject-imperative=true --compact
[FAIL] CC003 subject_imperative: docs: revamped the profile

Both are text written for a person, so they should agree.

Why kebab, and why JSON stays as it is

The two conventions each have a job, and only one surface was on the wrong side of the line:

Kebab is the form the rules reference titles each rule with (### subject-imperative (CC003)), so a name printed to a terminal can be pasted into the docs and found. That is already why the default output converts.

The JSON check field is deliberately untouched: it carries the snake_case key so a consumer can map a failure back to the cchk.toml option that controls it. commit-check-action depends on exactly that — it takes the raw key and converts it itself for display, which is the clearest evidence that the display form is meant to be kebab throughout.

The change

Both call sites now go through one display_name() helper instead of one of them open-coding .replace("_", "-"). That open-coding is how the two drifted apart in the first place, so a shared helper is the part that stops it recurring.

Compatibility

--compact landed in 2.6.0 and is described as being for CI logs. The format of the line is unchanged — only the check name's spelling. The machine-readable path, --format json, is untouched.

The one risk worth naming: anyone grepping subject_imperative out of --compact output would need to grep subject-imperative instead. Whether that is worth a minor or a major is your call — I have no way to see how the flag is used in the wild.

Test plan

A new test asserts the form both text outputs print. The suite had no such assertion, which is how this shipped: test_compact_shows_one_line_per_failure only checks that each line starts with [FAIL].

Verified by reverting the fix and confirming the test fails:

E  assert 'CC003 subject-imperative:' in '[FAIL] CC003 subject_imperative: docs: revamped the profile\n'

Worth noting, because my first attempt at this test passed against the broken code: it asserted on the default -m run, whose failing check is message — a name with no underscore, so the two forms are identical and the assertion could not discriminate. The test now drives --subject-imperative=true specifically to get a name that differs between the forms.

Full suite: 506 passed. Two failures are pre-existing on unmodified main in this environment and unrelated to this change — test_load_config_file_permission_error (does not raise when the suite runs as root) and TestAiAttributionValidator::test_empty_message_passes.

Note on the branch name

AGENTS.md asks for a Conventional Branch type, and claude/ is not in the list it gives — my session is pinned to this branch name. The repository's own cchk.toml sets conventional_branch = false, so CI does not enforce it, and claude/ is in the tool's own default allow-list. Happy to move it if you would rather it read fix/.

Generated by Claude Code

Summary by CodeRabbit

• Bug Fixes

  • Check names are now displayed consistently in kebab-case across compact failure output and standard error messages.
  • Corrected output for checks configured with underscore-based names.

• Tests

  • Added regression coverage to verify compact output uses the expected check names.