music_library/backlog/completed/ml-7 - Tighten-vague-test-assertions-in-scrobble_activity-and-worker-tests.md

id, title, status, assignee, created_date, labels, dependencies, references, priority

id	title	status	assignee	created_date	labels	dependencies	references	priority
ML-7	Tighten vague test assertions in scrobble_activity and worker tests	Done		2026-04-20 08:49			https://github.com/cloud8421/music_library/issues/176	low

Description

GitHub: created 2026-04-16 · updated 2026-04-20 · closed 2026-04-20

Summary

Project convention: "Assert specific values, not just shape. Wildcard matches (_) in assertions are a signal the test is too vague." Several test files violate this.

Evidence

Bare assert {:ok, _} = ... (9 instances in one file)

test/music_library/scrobble_activity_test.exs: lines 43, 48, 96, 101, 154, 161, 223, 251, 272

The context's entire job is to shape Last.fm payloads correctly, yet the tests don't inspect the returned struct's fields.

assert X != nil (9 sites, 4 files)

• test/music_library/worker/prune_assets_test.exs:14, 26, 38
• test/music_library/worker/fetch_artist_info_test.exs:104, 105
• test/music_library/barcode_scan_test.exs:23, 63, 100
• test/music_library/worker/fetch_artist_image_test.exs:28

Other {:ok, _} (selected)

• test/music_library/assets_test.exs:29, 30
• test/music_library/records/similarity_test.exs:218, 229
• test/music_library/chats_test.exs:162, 203

Fix

For each site, replace with an assertion that pins a specific value the function is responsible for producing.

Acceptance Criteria

• scrobble_activity_test.exs tests assert specific struct fields on each {:ok, _} site
• No assert X != nil in worker test files (replace with value assertion)
• Suite still passes

• #1 scrobble_activity_test.exs tests assert specific struct fields on each {:ok, _} site
• #2 No assert X != nil in worker test files (replace with value assertion)
• #3 Suite still passes