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, 43 insertions, 0 deletions

diff --git a/tests/test-debug-wttrin-enable.el b/tests/test-debug-wttrin-enable.el
new file mode 100644
index 0000000..569547d
--- /dev/null
+++ b/tests/test-debug-wttrin-enable.el
@@ -0,0 +1,43 @@
+;;; test-debug-wttrin-enable.el --- Tests for debug-wttrin-enable -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2025-2026 Craig Jennings
+
+;;; Commentary:
+
+;; Unit tests for debug-wttrin-enable.  Verifies the interactive command
+;; flips `wttrin-debug' to t and is idempotent when already enabled.
+
+;;; 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-debug-wttrin-enable-normal-flips-from-nil-to-t ()
+  "Calling enable when wttrin-debug is nil sets it to t."
+  (let ((wttrin-debug nil))
+    (debug-wttrin-enable)
+    (should (eq wttrin-debug t))))
+
+(ert-deftest test-debug-wttrin-enable-normal-idempotent-when-already-enabled ()
+  "Calling enable when wttrin-debug is already t leaves it t."
+  (let ((wttrin-debug t))
+    (debug-wttrin-enable)
+    (should (eq wttrin-debug t))))
+
+;;; Boundary Cases
+
+(ert-deftest test-debug-wttrin-enable-boundary-overrides-non-boolean-truthy-value ()
+  "Calling enable replaces a non-boolean truthy value with t."
+  (let ((wttrin-debug 'verbose))
+    (debug-wttrin-enable)
+    (should (eq wttrin-debug t))))
+
+(provide 'test-debug-wttrin-enable)
+;;; test-debug-wttrin-enable.el ends here