--- id: doc-24 title: "Audit Report: LiveComponent → Parent handle_info Coverage (Phase 1)" type: other created_date: "2026-05-19 06:35" tags: - audit - liveview - handle_info - components --- # Phase 1 Async Message Audit: LiveComponent → Parent handle_info Coverage **Date:** 2026-05-19 **Scope:** All `send(self(), ...)` call sites in LiveComponents matched against `handle_info` clauses in parent LiveViews. ## Executive Summary **Result: PASS — No critical bugs found.** All 11 message-producing components have their messages properly handled by their parent LiveViews. The pre-flagged Release component concern was a false positive — the component safely skips sending when `on_release_loaded` is nil. --- ## Complete Producer → Consumer Matrix ### Components (lib/music_library_web/components/) #### 1. RecordForm (`MusicLibraryWeb.Components.RecordForm`) - **File:** `lib/music_library_web/components/record_form.ex` - **Send pattern:** `send(self(), {__MODULE__, {:saved, record}})` (lines 564, 603) - **Consumers:** | LiveView | File | Line | Message | Status | | -------------------- | ----------------------------------------------------- | -------- | ------------------- | -------------------------- | | CollectionLive.Show | `lib/music_library_web/live/collection_live/show.ex` | 338, 461 | `{:saved, record}` | ✅ Full match | | CollectionLive.Index | `lib/music_library_web/live/collection_live/index.ex` | 177, 291 | `{:saved, _record}` | ✅ Match (ignores payload) | | WishlistLive.Show | `lib/music_library_web/live/wishlist_live/show.ex` | 274, 355 | `{:saved, record}` | ✅ Full match | | WishlistLive.Index | `lib/music_library_web/live/wishlist_live/index.ex` | 144, 212 | `{:saved, _record}` | ✅ Match (ignores payload) | #### 2. AddRecord (`MusicLibraryWeb.Components.AddRecord`) - **File:** `lib/music_library_web/components/add_record.ex` - **Send pattern:** `send(self(), {__MODULE__, msg})` (line 574) - **Messages:** `{:imported_single, record}` (line 452), `{:imported_async, count}` (line 435) - **Consumers:** | LiveView | File | Line | Message | Status | | -------------------- | ----------------------------------------------------- | ------------- | ------------- | ------ | | CollectionLive.Index | `lib/music_library_web/live/collection_live/index.ex` | 193, 295, 299 | Both messages | ✅ | | WishlistLive.Index | `lib/music_library_web/live/wishlist_live/index.ex` | 160, 216, 220 | Both messages | ✅ | #### 3. Chat (`MusicLibraryWeb.Components.Chat`) - **File:** `lib/music_library_web/components/chat.ex` - **Send pattern:** `send(self(), {__MODULE__, :chats_changed})` (lines 344, 431) - **Consumers:** | LiveView | File | Line | Message | Status | | -------------------- | ----------------------------------------------------- | -------- | ---------------- | ------ | | CollectionLive.Show | `lib/music_library_web/live/collection_live/show.ex` | 322, 469 | `:chats_changed` | ✅ | | CollectionLive.Index | `lib/music_library_web/live/collection_live/index.ex` | 225, 303 | `:chats_changed` | ✅ | | WishlistLive.Show | `lib/music_library_web/live/wishlist_live/show.ex` | 258, 362 | `:chats_changed` | ✅ | | ArtistLive.Show | `lib/music_library_web/live/artist_live/show.ex` | 477, 630 | `:chats_changed` | ✅ | #### 4. Release (`MusicLibraryWeb.Components.Release`) - **File:** `lib/music_library_web/components/release.ex` - **Send pattern:** `send(self(), {tag, release})` (line 82) — **non-MODULE pattern** - **Consumers:** | LiveView | File | Line | on_release_loaded | handle_info | Status | | ------------------------ | ---------------------------------------------------------- | ------ | ------------------- | ---------------------------------------------- | ----------- | | ScrobbleLive.ReleaseShow | `lib/music_library_web/live/scrobble_live/release_show.ex` | 41, 68 | `{:release_loaded}` | `handle_info({:release_loaded, release}, ...)` | ✅ | | CollectionLive.Show | `lib/music_library_web/live/collection_live/show.ex` | 304 | (not set = nil) | N/A — no message sent | ✅ Harmless | **CollectionLive.Show analysis:** The component's `notify_release_loaded/2` checks `socket.assigns[:on_release_loaded]` before sending. When nil (as in CollectionLive.Show), it returns `:ok` without calling `send/2`. This is intentional — CollectionLive.Show doesn't need to react to release loading. **No dead message, no missing handler.** #### 5. ScrobbleRulePicker (`MusicLibraryWeb.ScrobbleRulePicker`) - **File:** `lib/music_library_web/components/scrobble_rule_picker.ex` - **Send pattern:** `send(self(), {__MODULE__, {:rule_created, rule}})` (line 191/212) - **Consumers:** | LiveView | File | Line | Status | | ------------------------- | ----------------------------------------------------------- | -------- | ------ | | ScrobbledTracksLive.Index | `lib/music_library_web/live/scrobbled_tracks_live/index.ex` | 215, 283 | ✅ | | StatsLive.Index | `lib/music_library_web/live/stats_live/index.ex` | 57, 167 | ✅ | Note: Not rendered in ScrobbleRulesLive.Index — that LiveView only uses ScrobbleRulesLive.Form. --- ### Form Components (lib/music_library_web/live/\*/form.ex) #### 6. ArtistLive.Form (`MusicLibraryWeb.ArtistLive.Form`) - **File:** `lib/music_library_web/live/artist_live/form.ex` - **Messages:** `{:saved, artist_info}` (lines 279, 319) - **Consumer:** `artist_live/show.ex:493, 639` ✅ #### 7. RecordSetLive.Form (`MusicLibraryWeb.RecordSetLive.Form`) - **File:** `lib/music_library_web/live/record_set_live/form.ex` - **Messages:** `{:updated, record_set}` (line 74), `{:created, record_set}` (line 87) - **Consumers:** | LiveView | File | Lines | Messages handled | Status | | ------------------- | ----------------------------------------------------- | ------------ | ----------------------- | --------------------------------------------------------------------------------------- | | RecordSetLive.Show | `lib/music_library_web/live/record_set_live/show.ex` | 185, 227 | `:updated` only | ✅ Correct — Show only renders Form in `:edit` mode (line 180: `@live_action == :edit`) | | RecordSetLive.Index | `lib/music_library_web/live/record_set_live/index.ex` | 94, 192, 199 | `:created` + `:updated` | ✅ | #### 8. RecordSetLive.RecordPicker (`MusicLibraryWeb.RecordSetLive.RecordPicker`) - **File:** `lib/music_library_web/live/record_set_live/record_picker.ex` - **Message:** `{:added, updated_set}` (line 191) - **Consumers:** - `record_set_live/show.ex:201, 237` ✅ - `record_set_live/index.ex:108, 206` ✅ #### 9. ScrobbleRulesLive.Form (`MusicLibraryWeb.ScrobbleRulesLive.Form`) - **File:** `lib/music_library_web/live/scrobble_rules_live/form.ex` - **Messages:** `{:updated, scrobble_rule}` (line 93), `{:created, scrobble_rule}` (line 106) - **Consumer:** `scrobble_rules_live/index.ex:249, 259` ✅ #### 10. ScrobbledTracksLive.Form (`MusicLibraryWeb.ScrobbledTracksLive.Form`) - **File:** `lib/music_library_web/live/scrobbled_tracks_live/form.ex` - **Message:** `{:saved, track}` (line 109) - **Consumer:** `scrobbled_tracks_live/index.ex:271` ✅ #### 11. OnlineStoreTemplateLive.Form (`MusicLibraryWeb.OnlineStoreTemplateLive.Form`) - **File:** `lib/music_library_web/live/online_store_template_live/form.ex` - **Message:** `{:saved, template}` (lines 117, 130) - **Consumer:** `online_store_template_live/index.ex:199` ✅ --- ## Non-MODULE Pattern Audit (Acceptance Criterion #4) Three non-`{__MODULE__, _}` patterns were found: 1. **Release component** (`release.ex:82`) — `send(self(), {tag, release})` where tag is a dynamic assign - **Severity:** LOW — design note only - **Status:** Correctly handled in ScrobbleLive.ReleaseShow; safely no-ops in CollectionLive.Show - **Risk:** If a new consumer sets a non-atom tag (e.g., a string), pattern matching could fail silently. The `handle_info` clauses pattern-match on atoms (`:release_loaded`). - **Recommendation:** Consider using `{__MODULE__, {:loaded, release}}` for type safety, but not required. 2. **ScrobbleLive.Index** (`scrobble_live/index.ex:123,139`) — `send(self(), {:perform_search, query})` - **Severity:** INFO — self-send within same LiveView, not a component→parent message - **Status:** Has matching `handle_info({:perform_search, query}, ...)` at line 145 ✅ 3. **ShowToast hook** (`hooks/show_toast.ex:8`) — `send(self(), {:put_toast, type, message})` - **Severity:** N/A — standard LiveView `attach_hook` pattern - **Status:** Intercepted by `maybe_put_toast/2` hook before reaching `handle_info` ✅ --- ## handle_info Clauses Without Corresponding Component Sends These `handle_info` clauses exist in LiveViews but receive messages from non-component sources (PubSub broadcast, Phoenix channels): | LiveView | Message | Source | | ------------------------- | ------------------------ | ---------------------------------------------- | | CollectionLive.Index | `:records_index_changed` | PubSub from Records context | | WishlistLive.Index | `:records_index_changed` | PubSub from Records context | | CollectionLive.Show | `{:update, record}` | PubSub from Records context (`records.ex:126`) | | WishlistLive.Show | `{:update, record}` | PubSub from Records context (`records.ex:126`) | | ScrobbledTracksLive.Index | `%{track_count: _}` | PubSub from ScrobbleActivity context | | StatsLive.Index | `%{track_count: _}` | PubSub from ScrobbleActivity context | | MaintenanceLive.Index | `:update_job_counts` | Self-send or timer | These are all correctly handled and outside the scope of this component audit. --- ## Coverage Statistics - **11/11 components verified** ✅ - **14 send(self()) call sites** across all components - **22 handle_info clauses** in parent LiveViews matching component messages - **0 missing handlers** found - **0 dead messages** found - **3 non-MODULE patterns** — all verified safe --- ## Recommendations 1. **LOW:** The Release component's dynamic tag pattern (`send(self(), {tag, release})`) works correctly but could be made type-safe by using `{__MODULE__, {:loaded, release}}` with a static atom. This would prevent accidental non-atom tags and make message tracing easier. **Not blocking.** 2. **INFO:** All `.ex` form components under `lib/music_library_web/live/*/form.ex` follow an identical `notify_parent/1` → `{__MODULE__, msg}` pattern. This is consistent and well-structured. **No changes needed.** 3. **INFO:** The `RecordSetLive.Show` only handles `{:updated, ...}` from `RecordSetLive.Form` — this is correct because the Show LiveView only renders the Form in `:edit` mode. No missing handler. **No changes needed.**