feat(coverage): wire make coverage target + simplecov pipeline

2026-04-23T00:58:00+00:00

Completes the coverage v1 pipeline by adding the Makefile target, the undercover driver script, the exclusion list, and the .gitignore entry. Uses simplecov JSON rather than LCOV as the collection format. The LCOV vs simplecov choice: Undercover's :merge-report t option only supports simplecov. Since the pipeline runs tests per-file (matching test-unit's isolation pattern) and accumulates coverage across runs, merge-report is required. LCOV is better-supported by external coverage viewers, but for a primarily interactive workflow the on-disk format is an internal detail. Other moves in this commit: - Renamed cj/--coverage-parse-lcov to cj/--coverage-parse-simplecov and rewrote its tests for the JSON schema. Same signature, same semantics (file to set of covered lines), different parser. - Renamed the backend protocol's :lcov-path key to :report-path, format-neutral and matching the renamed cj/--coverage-elisp-report-path function. - The coverage target deletes modules/*.elc before running so undercover can instrument the .el sources. Without this, byte-compiled versions shadow the instrumentation and only a handful of pre-loaded modules end up with coverage data. - Excluded tests/test-all-comp-errors.el from make coverage runs. That test byte-compiles every module, which fails under undercover's instrumentation. Excluded only from coverage. Normal make test still runs it. - Updated docs/design/coverage.org to reflect the simplecov pivot with a historical note on why we moved off LCOV. Verified end-to-end: make coverage produces .coverage/simplecov.json with 2717 of 4559 executable lines hit across 44 tracked modules.

feat(coverage): add elisp backend

2026-04-22T22:17:05+00:00

First of the pluggable coverage backends. Registers itself with coverage-core on load. - :name is elisp - :detect returns non-nil when the project root has a Makefile, Eask, or Cask alongside .el files at root or under modules/. The heuristic is deliberately loose. For anything unusual, .dir-locals.el can pin the backend with cj/coverage-backend. - :run invokes make coverage in a compilation buffer. On success the callback fires with the LCOV path. On failure the buffer stays visible so the user can read the error. - :lcov-path resolves to /.coverage/lcov.info. undercover is declared via use-package with :defer t so it's installed but not loaded at Emacs startup. The make coverage target will require it explicitly. Tests cover Normal (Makefile + modules/, Eask + root .el, Cask + modules/), Boundary (no build file, Makefile without .el, empty directory), and Error (nonexistent root returns nil). The registration-on-load case is also verified. The Makefile coverage target and the cj/coverage-report user command arrive in follow-up commits.

dotemacs/tests/test-coverage-elisp--detect.el, branch main

feat(coverage): wire make coverage target + simplecov pipeline

feat(coverage): add elisp backend