use pathlib in tests: make _common.RSRC a pathlib.Path

[snejus]

Part of #6807

What changed

• This change standardizes test resource paths by making _common.RSRC a pathlib.Path instead of a bytes path.
• Test code now builds paths with / and uses Path helpers like read_text(), read_bytes(), open(), stat(), and resolve().
• Path handling setup in beets/test/_common.py is simplified, and old byte-string path conversions are removed from many tests.

Why

• Before, test code mixed os.path, byte paths, string decoding, and utility conversions.
• Now, resource path handling has one clear shape: Path objects.
• This reduces path-conversion noise and makes test helpers easier to read and reuse.

[github-actions]

Thank you for the PR! The changelog has not been updated, so here is a friendly reminder to check if you need to add an entry.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 75.62%. Comparing base (8778d0e) to head (bfd3b7e).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #6850      +/-   ##
==========================================
- Coverage   75.63%   75.62%   -0.01%     
==========================================
  Files         163      163              
  Lines       21317    21317              
  Branches     3361     3361              
==========================================
- Hits        16124    16122       -2     
- Misses       4403     4404       +1     
- Partials      790      791       +1     

see 1 file with indirect coverage changes

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[Copilot]

Pull request overview

grug see PR try make test resource path _common.RSRC be pathlib.Path, so tests stop juggling bytes/str/os.path and use /, .open(), .read_bytes(), .stat(), etc.

Changes:

• make beets/test/_common.py::RSRC be Path and adjust PLUGINPATH to string
• update many tests to build resource paths via RSRC / "file.ext" and use Path helpers
• remove some old bytes-path glue in tests

Reviewed changes

Copilot reviewed 37 out of 37 changed files in this pull request and generated 10 comments.

Show a summary per file

File	Description
beets/test/_common.py	redefine RSRC as Path and adjust plugin path string
beets/test/helper.py	use RSRC Path in fixtures (but one place still assigns Path into byte-only Item["path"])
test/util/test_m3ufile.py	use RSRC / ... for playlist fixtures
test/util/test_art_resize.py	use Path for image fixture constant
test/ui/commands/test_utils.py	simplify copy of resource media file using Path
test/ui/commands/test_update.py	use Path for resource media inputs
test/ui/commands/test_completion.py	load completion script via Path.open()
test/test_library.py	use Path resource for unreadable file and unicode-path test (but .path assignment needs bytes)
test/test_importer.py	use Path resource joins in importer tests (but importer.paths overwrites must stay bytes)
test/plugins/test_web.py	use Path for resource media and URL path construction
test/plugins/test_spotify.py	read mock JSON via Path.read_bytes()
test/plugins/test_replace.py	remove .decode() and use RSRC Path directly
test/plugins/test_plugin_mediafield.py	use RSRC Path when copying fixture file
test/plugins/test_metasync.py	use RSRC Path for itunes xml fixtures
test/plugins/test_embedart.py	switch art fixture paths to Path and simplify display string
test/plugins/test_convert.py	switch convert stub/art paths to Path (but .artpath assignment must stay bytes)
test/plugins/test_art.py	switch some fixture paths to Path (linked issue says this file was scope-exempt)
test/plugins/test_acousticbrainz.py	load JSON via Path.read_text() + json.loads()