feat(music): tag completion, aligned listings, numbered playlist rows

The radio tag search now completes over popular tags from radio-browser's /json/tags endpoint (station-count order, capped at 500, cached per session), so the prompt offers real tags instead of a blind guess. Free-form input still works, and a failed fetch degrades to plain input.

Station listings align into columns: the votes field pads to a fixed width, and each annotation pads out to the widest candidate name.

Playlist rows carry a numeric overlay prefix, rebuilt after every change by a debounced after-change hook, so the cursor stays visible on cover-art thumbnails and each row's position is readable. Overlays leave the buffer text to EMMS.

Also fixed: the search now trims queries before they hit the API (a trailing space used to reach it as %20 and match nothing).

1 files changed, 79 insertions, 0 deletions

diff --git a/tests/test-music-config--radio-tags.el b/tests/test-music-config--radio-tags.el
new file mode 100644
index 00000000..60e1c9d8
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+++ b/tests/test-music-config--radio-tags.el
@@ -0,0 +1,79 @@
+;;; test-music-config--radio-tags.el --- Tests for radio-browser tag pre-population -*- coding: utf-8; lexical-binding: t; -*-
+;;
+;; Author: Craig Jennings <c@cjennings.net>
+;;
+;;; Commentary:
+;; The tag-search prompt completes over the popular tags fetched from
+;; radio-browser's /json/tags endpoint (cached per session).  These tests cover
+;; the pure pieces: the endpoint URL, the parse (trim + drop-empty + dedupe,
+;; since the source data is user-generated and dirty), and the session cache.
+;; The network GET is mocked at the boundary.
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+
+(defvar cj/custom-keymap (make-sparse-keymap)
+  "Stub keymap for testing.")
+
+(require 'music-config)
+
+(defconst test-music-radio-tags--fixture
+  (concat "[{\"name\":\"jazz \",\"stationcount\":300},"
+          "{\"name\":\" jazz\",\"stationcount\":5},"
+          "{\"name\":\"\",\"stationcount\":2},"
+          "{\"name\":\"rock\",\"stationcount\":100}]")
+  "A recorded /json/tags response with whitespace, empty, and duplicate names.")
+
+;;; Normal Cases
+
+(ert-deftest test-music-radio-tags-url-shape ()
+  "Normal: the tags URL targets /json/tags ordered by station count with the limit."
+  (let* ((cj/music-radio-tag-limit 500)
+         (u (cj/music-radio--tags-url "de1.api.radio-browser.info")))
+    (should (string-match-p "/json/tags" u))
+    (should (string-match-p "order=stationcount" u))
+    (should (string-match-p "limit=500" u))))
+
+(ert-deftest test-music-radio-parse-tags-trims-dedupes-drops-empty ()
+  "Normal: tag names come back trimmed, deduped, and without empties."
+  (should (equal (cj/music-radio--parse-tags test-music-radio-tags--fixture)
+                 '("jazz" "rock"))))
+
+(ert-deftest test-music-radio-available-tags-caches-per-session ()
+  "Normal: the fetch runs once; later calls serve the cache."
+  (let ((cj/music-radio--tags-cache nil)
+        (calls 0))
+    (cl-letf (((symbol-function 'cj/music-radio--http-get)
+               (lambda (_url) (cl-incf calls) test-music-radio-tags--fixture)))
+      (should (equal (cj/music-radio--available-tags) '("jazz" "rock")))
+      (should (equal (cj/music-radio--available-tags) '("jazz" "rock")))
+      (should (= calls 1)))))
+
+;;; Boundary Cases
+
+(ert-deftest test-music-radio-parse-tags-empty-array ()
+  "Boundary: an empty tag array parses to nil."
+  (should-not (cj/music-radio--parse-tags "[]")))
+
+;;; Error Cases
+
+(ert-deftest test-music-radio-available-tags-fetch-failure-returns-nil-and-retries ()
+  "Error: a failed fetch yields nil, leaves the cache empty, and retries next call."
+  (let ((cj/music-radio--tags-cache nil)
+        (calls 0))
+    (cl-letf (((symbol-function 'cj/music-radio--http-get)
+               (lambda (_url) (cl-incf calls) nil)))
+      (should-not (cj/music-radio--available-tags))
+      (should-not cj/music-radio--tags-cache)
+      (should-not (cj/music-radio--available-tags))
+      (should (= calls 2)))))
+
+(ert-deftest test-music-radio-parse-tags-malformed-user-errors ()
+  "Error: a non-JSON body signals user-error, not a raw parse error."
+  (should-error (cj/music-radio--parse-tags "<html>502</html>")
+                :type 'user-error))
+
+(provide 'test-music-config--radio-tags)
+;;; test-music-config--radio-tags.el ends here