Added Unique Index for user_id & juke_session

src/jukebox/juke-session/entities/membership.entity.ts

@@ -1,9 +1,10 @@
 import { EntityBase } from 'src/config/entities'
 import { QueuedTrack } from 'src/jukebox/queue/entities/queued-track.entity'
-import { Column, Entity, ManyToOne, OneToMany } from 'typeorm'
+import { Column, Entity, Index, ManyToOne, OneToMany } from 'typeorm'
 import { JukeSession } from './juke-session.entity'
 
 @Entity('juke_session_membership')
+@Index('unique_user_per_session', ['juke_session', 'user_id'], { unique: true })
 export class JukeSessionMembership extends EntityBase {
   @ManyToOne(() => JukeSession, (juke_session) => juke_session.memberships)
   juke_session: JukeSession

src/jukebox/juke-session/juke-session.service.ts

@@ -214,7 +214,23 @@ export class JukeSessionService {
       juke_session: { id: jukeSessionId },
       ...payload,
     })
-    const createdMembership = await this.membershipRepo.save(preMembership)
+
+    var createdMembership: JukeSessionMembership
+    try {
+      createdMembership = await this.membershipRepo.save(preMembership)
+    } catch (err) {
+      const dbError = err.driverError
+      // Checks Postgres Unique Constraint Error Code
+      if (err instanceof QueryFailedError && dbError?.code === '23505') {
+        if (dbError.constraint === 'unique_user_per_session') {
+          throw new InternalServerErrorException(
+            'Failed to generate membership, an user_id already exists on this session',
+          )
+        }
+      }
+      throw err
+    }
+
     const membership = await this.getMembership(createdMembership.id)
     return membership
   }