Improve performance of deleting watchlist item

apps/api/src/app/endpoints/watchlist/watchlist.controller.ts

@@ -52,14 +52,13 @@ export class WatchlistController {
     @Param('dataSource') dataSource: DataSource,
     @Param('symbol') symbol: string
   ) {
-    const watchlistItems =
-      await this.watchlistService.getWatchlistItems(userId);
-
-    const watchlistItem = watchlistItems.find((item) => {
-      return item.dataSource === dataSource && item.symbol === symbol;
+    const hasWatchlistItem = await this.watchlistService.hasWatchlistItem({
+      dataSource,
+      symbol,
+      userId
     });
 
-    if (!watchlistItem) {
+    if (!hasWatchlistItem) {
       throw new HttpException(
         getReasonPhrase(StatusCodes.NOT_FOUND),
         StatusCodes.NOT_FOUND

apps/api/src/app/endpoints/watchlist/watchlist.service.ts

@@ -152,4 +152,21 @@ export class WatchlistService {
       return a.name.localeCompare(b.name);
     });
   }
+
+  public async hasWatchlistItem({
+    dataSource,
+    symbol,
+    userId
+  }: { userId: string } & AssetProfileIdentifier): Promise<boolean> {
+    const assetProfile = await this.prismaService.symbolProfile.findFirst({
+      select: { id: true },
+      where: {
+        dataSource,
+        symbol,
+        watchedBy: { some: { id: userId } }
+      }
+    });
+
+    return !!assetProfile;
+  }
 }