test: cover wttrin-debug.el and expand lint to all source files

I added 24 unit tests across six new files for wttrin-debug.el. They cover enable/disable, the debug-log writer, clear-log, show-log, and the mode-line diagnostic dump. That lifts wttrin-debug.el coverage from 27% to 95%, and overall coverage from 84% to 94%. Each function gets Normal / Boundary / Error categories where applicable. Globals like `wttrin-debug` and `wttrin--debug-log` are isolated per test with let-bindings. The dynamic-scope rebinding restores state cleanly at exit.

I expanded the `lint` target to run on all three source files instead of just `wttrin.el`. Checkdoc and elisp-lint run on every file. Package-lint stays scoped to `wttrin.el` because the others aren't standalone packages.

The tricky bit: `elisp-lint-file` re-runs package-lint internally as one of its validators. So the explicit guard alone wasn't enough. The fix binds `elisp-lint-ignored-validators` to include "package-lint" for the secondaries, which suppresses the re-run at the validator level.

I also added `*-autoloads.el` to .gitignore. Eask generates `emacs-wttrin-autoloads.el` during install, and it shouldn't be tracked.

I skipped one function: `wttrin--debug-mode-line-info` is a one-line dispatcher to `debug-wttrin-mode-line`. Testing it would assert the dispatch happened, which only tests Emacs.

1 files changed, 45 insertions, 0 deletions

diff --git a/tests/test-wttrin-debug-clear-log.el b/tests/test-wttrin-debug-clear-log.el
new file mode 100644
index 0000000..10e4c21
--- /dev/null
+++ b/tests/test-wttrin-debug-clear-log.el
@@ -0,0 +1,45 @@
+;;; test-wttrin-debug-clear-log.el --- Tests for wttrin-debug-clear-log -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2025-2026 Craig Jennings
+
+;;; Commentary:
+
+;; Unit tests for wttrin-debug-clear-log.  Verifies the interactive
+;; command empties the debug log alist regardless of prior state.
+
+;;; Code:
+
+(require 'ert)
+(require 'wttrin)
+(require 'testutil-wttrin)
+
+(require 'wttrin-debug
+         (expand-file-name "wttrin-debug.el"
+                           (file-name-directory (locate-library "wttrin"))))
+
+;;; Normal Cases
+
+(ert-deftest test-wttrin-debug-clear-log-normal-empties-populated-log ()
+  "Clearing a non-empty log leaves it nil."
+  (let ((wttrin--debug-log '(("00:00:01.000" . "one")
+                             ("00:00:02.000" . "two"))))
+    (wttrin-debug-clear-log)
+    (should-not wttrin--debug-log)))
+
+(ert-deftest test-wttrin-debug-clear-log-normal-multiple-calls-stay-empty ()
+  "Calling clear twice in a row leaves the log empty."
+  (let ((wttrin--debug-log '(("00:00:01.000" . "one"))))
+    (wttrin-debug-clear-log)
+    (wttrin-debug-clear-log)
+    (should-not wttrin--debug-log)))
+
+;;; Boundary Cases
+
+(ert-deftest test-wttrin-debug-clear-log-boundary-clearing-already-empty-log ()
+  "Clearing an already-empty log is a no-op and leaves it nil."
+  (let ((wttrin--debug-log nil))
+    (wttrin-debug-clear-log)
+    (should-not wttrin--debug-log)))
+
+(provide 'test-wttrin-debug-clear-log)
+;;; test-wttrin-debug-clear-log.el ends here