search: address review findings

Prefix result keys per type so ids shared across songs, albums, artists
and playlists cannot collide and crash the list; add a loading state so
a query in flight no longer reads as no results; gate on code points to
match SQLite's length(); bind the three-character floor to one constant;
label the search field for TalkBack; and drop the vacuous trigram-plan
test. Cancel the ViewModel scope in its test teardown so it cannot leak
into later Robolectric tests.

app/src/main/kotlin/com/subtracks/data/db/LibraryDao.kt

@@ -130,20 +130,22 @@ internal const val PLAYLIST_ORDER_BY_UPDATED_REVERSED = "changed ASC, name COLLA
 
 // Cross-type search only runs from three characters, since a shorter term cannot use the trigram
 // index and scanning the whole library for it is not worth it.
+const val SEARCH_MIN_LENGTH = 3
+
 internal const val ALBUM_SEARCH_FILTER =
-    "(length(:search) >= 3 AND rowid IN (SELECT rowid FROM album_search " +
+    "(length(:search) >= $SEARCH_MIN_LENGTH AND rowid IN (SELECT rowid FROM album_search " +
         "WHERE album_search MATCH '\"' || replace(:search, '\"', '\"\"') || '\"'))"
 
 internal const val ARTIST_SEARCH_FILTER =
-    "(length(:search) >= 3 AND rowid IN (SELECT rowid FROM artist_search " +
+    "(length(:search) >= $SEARCH_MIN_LENGTH AND rowid IN (SELECT rowid FROM artist_search " +
         "WHERE artist_search MATCH '\"' || replace(:search, '\"', '\"\"') || '\"'))"
 
 internal const val PLAYLIST_SEARCH_FILTER =
-    "(length(:search) >= 3 AND rowid IN (SELECT rowid FROM playlist_search " +
+    "(length(:search) >= $SEARCH_MIN_LENGTH AND rowid IN (SELECT rowid FROM playlist_search " +
         "WHERE playlist_search MATCH '\"' || replace(:search, '\"', '\"\"') || '\"'))"
 
 internal const val SONG_SEARCH_FILTER =
-    "(length(:search) >= 3 AND songs.rowid IN (SELECT rowid FROM song_search " +
+    "(length(:search) >= $SEARCH_MIN_LENGTH AND songs.rowid IN (SELECT rowid FROM song_search " +
         "WHERE song_search MATCH '\"' || replace(:search, '\"', '\"\"') || '\"'))"
 
 @Dao

app/src/main/kotlin/com/subtracks/data/repo/LibraryRepository.kt

@@ -510,6 +510,4 @@ const val REDISCOVER_WINDOW_MS = 60L * 24 * 60 * 60 * 1000
 
 const val SEARCH_RESULT_LIMIT = 50
 
-const val SEARCH_MIN_LENGTH = 3
-
 fun rediscoverCutoff(): Long = System.currentTimeMillis() - REDISCOVER_WINDOW_MS

app/src/main/kotlin/com/subtracks/ui/search/SearchScreen.kt

@@ -29,20 +29,23 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.focus.FocusRequester
 import androidx.compose.ui.focus.focusRequester
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.semantics.contentDescription
+import androidx.compose.ui.semantics.semantics
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import com.subtracks.data.db.SEARCH_MIN_LENGTH
 import com.subtracks.data.model.Album
 import com.subtracks.data.model.AlbumSongItem
 import com.subtracks.data.model.Artist
 import com.subtracks.data.model.CoverArtRef
 import com.subtracks.data.model.Playlist
 import com.subtracks.data.model.Song
-import com.subtracks.data.repo.SEARCH_MIN_LENGTH
 import com.subtracks.data.source.StarType
 import com.subtracks.playback.PlaybackController
 import com.subtracks.ui.components.ContextMenuHost
 import com.subtracks.ui.components.EmptyState
 import com.subtracks.ui.components.ItemActions
+import com.subtracks.ui.components.LoadingState
 import com.subtracks.ui.components.MenuTarget
 import com.subtracks.ui.home.AlbumListRow
 import com.subtracks.ui.home.ArtistListRow
@@ -138,20 +141,28 @@ fun SearchScreen(
                                 focusedIndicatorColor = Color.Transparent,
                                 unfocusedIndicatorColor = Color.Transparent,
                             ),
-                        modifier = Modifier.fillMaxWidth().focusRequester(focusRequester),
+                        modifier =
+                            Modifier
+                                .fillMaxWidth()
+                                .focusRequester(focusRequester)
+                                .semantics { contentDescription = "Search your library" },
                     )
                 },
             )
         },
     ) { padding ->
         when {
-            query.length < SEARCH_MIN_LENGTH -> {
+            !searchReady(query) -> {
                 EmptyState(
                     text = "Type at least $SEARCH_MIN_LENGTH characters to search.",
                     modifier = Modifier.padding(padding),
                 )
             }
 
+            results.loading -> {
+                LoadingState(Modifier.padding(padding))
+            }
+
             results.isEmpty -> {
                 EmptyState(
                     text = "No results for \u201C$query\u201D.",
@@ -194,7 +205,7 @@ private fun LazyListScope.songResults(
 ) {
     if (songs.isEmpty()) return
     resultHeader("Songs")
-    items(songs, key = { it.song.id }) { item ->
+    items(songs, key = { "song-${it.song.id}" }) { item ->
         SongRow(
             song = item.song,
             coverArtId = item.coverArt,
@@ -218,7 +229,7 @@ private fun LazyListScope.albumResults(
 ) {
     if (albums.isEmpty()) return
     resultHeader("Albums")
-    items(albums, key = { it.id }) { album ->
+    items(albums, key = { "album-${it.id}" }) { album ->
         AlbumListRow(
             album = album,
             coverArt = coverArt,
@@ -237,7 +248,7 @@ private fun LazyListScope.artistResults(
 ) {
     if (artists.isEmpty()) return
     resultHeader("Artists")
-    items(artists, key = { it.id }) { artist ->
+    items(artists, key = { "artist-${it.id}" }) { artist ->
         ArtistListRow(
             artist = artist,
             coverArt = coverArt,
@@ -256,7 +267,7 @@ private fun LazyListScope.playlistResults(
 ) {
     if (playlists.isEmpty()) return
     resultHeader("Playlists")
-    items(playlists, key = { it.id }) { playlist ->
+    items(playlists, key = { "playlist-${it.id}" }) { playlist ->
         PlaylistRow(
             playlist = playlist,
             coverArt = coverArt,

app/src/main/kotlin/com/subtracks/ui/search/SearchViewModel.kt

@@ -2,6 +2,7 @@ package com.subtracks.ui.search
 
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import com.subtracks.data.db.SEARCH_MIN_LENGTH
 import com.subtracks.data.model.Album
 import com.subtracks.data.model.AlbumSongItem
 import com.subtracks.data.model.Artist
@@ -9,7 +10,6 @@ import com.subtracks.data.model.CoverArtRef
 import com.subtracks.data.model.Playlist
 import com.subtracks.data.model.Song
 import com.subtracks.data.repo.LibraryRepository
-import com.subtracks.data.repo.SEARCH_MIN_LENGTH
 import com.subtracks.data.repo.SourceRepository
 import com.subtracks.playback.PlaybackController
 import com.subtracks.ui.home.playSongInContext
@@ -21,6 +21,7 @@ import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.flatMapLatest
 import kotlinx.coroutines.flow.flowOf
+import kotlinx.coroutines.flow.onStart
 import kotlinx.coroutines.flow.stateIn
 
 data class SearchResults(
@@ -28,11 +29,14 @@ data class SearchResults(
     val artists: List<Artist> = emptyList(),
     val playlists: List<Playlist> = emptyList(),
     val songs: List<AlbumSongItem> = emptyList(),
+    val loading: Boolean = false,
 ) {
     val isEmpty: Boolean
         get() = albums.isEmpty() && artists.isEmpty() && playlists.isEmpty() && songs.isEmpty()
 }
 
+internal fun searchReady(query: String): Boolean = query.codePointCount(0, query.length) >= SEARCH_MIN_LENGTH
+
 @OptIn(ExperimentalCoroutinesApi::class)
 class SearchViewModel(
     private val libraryRepository: LibraryRepository,
@@ -46,7 +50,7 @@ class SearchViewModel(
         libraryRepository.activeSourceId
             .flatMapLatest { sourceId ->
                 _query.flatMapLatest { text ->
-                    if (sourceId == null || text.length < SEARCH_MIN_LENGTH) {
+                    if (sourceId == null || !searchReady(text)) {
                         flowOf(SearchResults())
                     } else {
                         combine(
@@ -56,7 +60,7 @@ class SearchViewModel(
                             libraryRepository.searchSongs(sourceId, text),
                         ) { albums, artists, playlists, songs ->
                             SearchResults(albums, artists, playlists, songs)
-                        }
+                        }.onStart { emit(SearchResults(loading = true)) }
                     }
                 }
             }.stateIn(viewModelScope, SharingStarted.WhileSubscribed(5_000), SearchResults())