fix(playlist): allow removing the last track from a playlist

packages/discovery-provider/src/tasks/entity_manager/entities/playlist.py

@@ -677,7 +677,10 @@ def populate_playlist_record_metadata(
         # Update the playlist_record when the corresponding field exists
         # in playlist_metadata
         if key == "playlist_contents":
-            if not playlist_metadata.get(key):
+            # Use `is None` rather than a truthiness check so that an explicit
+            # empty list (the user removing the last track) is applied instead
+            # of being silently treated as "field omitted".
+            if playlist_metadata.get(key) is None:
                 continue
             playlist_record.playlist_contents = process_playlist_contents(
                 playlist_record,

packages/web/src/components/edit-collection/EditCollectionForm.tsx

@@ -195,7 +195,7 @@ export const EditCollectionForm = (props: EditCollectionFormProps) => {
             </Flex>
           ) : null}
         </Tile>
-        <CollectionTrackFieldArray />
+        <CollectionTrackFieldArray isUpload={isUpload} />
         {isUpload ? <AnchoredSubmitRow /> : <AnchoredSubmitRowEdit />}
         {playlist_id ? (
           <>

packages/web/src/components/edit/fields/CollectionTrackFieldArray.tsx

@@ -66,7 +66,13 @@ const makeTrackKey = (track: TrackForUpload | TrackForEdit, index: number) => {
   return `${track.metadata.track_id}${suffix}`
 }
 
-export const CollectionTrackFieldArray = () => {
+type CollectionTrackFieldArrayProps = {
+  isUpload?: boolean
+}
+
+export const CollectionTrackFieldArray = ({
+  isUpload = false
+}: CollectionTrackFieldArrayProps = {}) => {
   const [{ value: tracks }] =
     useField<(TrackForUpload | TrackForEdit)[]>('tracks')
 
@@ -104,7 +110,7 @@ export const CollectionTrackFieldArray = () => {
                           <CollectionTrackField
                             index={index}
                             remove={remove}
-                            disableDelete={tracks.length === 1}
+                            disableDelete={isUpload && tracks.length === 1}
                           />
                         </div>
                       )}