feat(recording): validate system audio device before recording

Add pre-recording validation that catches stale or drifted system audio
devices before they cause silent recordings. When the default audio
output changes (Bluetooth reconnect, device switch) between setup and
recording, the monitor device is auto-updated. Warns if no audio is
currently playing through the monitored sink.

Co-Authored-By: Craig Jennings <c@cjennings.net>

1 files changed, 67 insertions, 0 deletions

diff --git a/tests/test-video-audio-recording--source-exists-p.el b/tests/test-video-audio-recording--source-exists-p.el
new file mode 100644
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+++ b/tests/test-video-audio-recording--source-exists-p.el
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+;;; test-video-audio-recording--source-exists-p.el --- Tests for cj/recording--source-exists-p -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Unit tests for cj/recording--source-exists-p function.
+;; Tests checking whether a PulseAudio source exists in pactl output.
+
+;;; Code:
+
+(require 'ert)
+
+;; Stub dependencies before loading the module
+(defvar cj/custom-keymap (make-sparse-keymap)
+  "Stub keymap for testing.")
+
+(require 'video-audio-recording)
+
+;;; Test Fixtures Helper
+
+(defun test-load-fixture (filename)
+  "Load fixture file FILENAME from tests/fixtures directory."
+  (let ((fixture-path (expand-file-name
+                       (concat "tests/fixtures/" filename)
+                       user-emacs-directory)))
+    (with-temp-buffer
+      (insert-file-contents fixture-path)
+      (buffer-string))))
+
+;;; Normal Cases
+
+(ert-deftest test-source-exists-p-normal-existing-device-returns-t ()
+  "Test that an existing device returns non-nil."
+  (let ((output (test-load-fixture "pactl-output-normal.txt")))
+    (should (cj/recording--source-exists-p
+             "alsa_output.pci-0000_00_1f.3.analog-stereo.monitor" output))))
+
+(ert-deftest test-source-exists-p-normal-input-device-returns-t ()
+  "Test that an existing input device returns non-nil."
+  (let ((output (test-load-fixture "pactl-output-normal.txt")))
+    (should (cj/recording--source-exists-p
+             "alsa_input.pci-0000_00_1f.3.analog-stereo" output))))
+
+(ert-deftest test-source-exists-p-normal-bluetooth-device-returns-t ()
+  "Test that a Bluetooth device returns non-nil."
+  (let ((output (test-load-fixture "pactl-output-normal.txt")))
+    (should (cj/recording--source-exists-p
+             "bluez_input.00:1B:66:C0:91:6D" output))))
+
+;;; Boundary Cases
+
+(ert-deftest test-source-exists-p-boundary-nonexistent-device-returns-nil ()
+  "Test that a non-existent device returns nil."
+  (let ((output (test-load-fixture "pactl-output-normal.txt")))
+    (should-not (cj/recording--source-exists-p
+                 "nonexistent_device.monitor" output))))
+
+(ert-deftest test-source-exists-p-boundary-empty-output-returns-nil ()
+  "Test that empty pactl output returns nil."
+  (should-not (cj/recording--source-exists-p "any-device" "")))
+
+(ert-deftest test-source-exists-p-boundary-partial-name-no-match ()
+  "Test that partial device name does not match."
+  (let ((output (test-load-fixture "pactl-output-normal.txt")))
+    (should-not (cj/recording--source-exists-p
+                 "alsa_output.pci-0000_00_1f.3.analog-stereo" output))))
+
+(provide 'test-video-audio-recording--source-exists-p)
+;;; test-video-audio-recording--source-exists-p.el ends here