fix(redis): preserve empty arrays in payload

src/drivers/redis_adapter.ts

@@ -233,10 +233,13 @@ const ACQUIRE_JOB_SCRIPT = `
   })
   redis.call('HSET', active_key, job_id, active_data)
 
-  -- Return job with acquiredAt
-  local job = cjson.decode(job_data)
-  job.acquiredAt = now
-  return cjson.encode(job)
+  -- Return the raw stored JSON plus acquiredAt separately. Re-encoding the job
+  -- through cjson would coerce empty arrays into empty objects, so the payload
+  -- string is preserved verbatim and merged on the JS side.
+  return cjson.encode({
+    data = job_data,
+    acquiredAt = now
+  })
 `
 
 /**
@@ -517,7 +520,9 @@ const GET_JOB_SCRIPT = `
 
   return cjson.encode({
     status = status,
-    data = cjson.decode(job_data),
+    -- Return the raw stored JSON for the job data. Re-encoding it through cjson
+    -- would coerce empty arrays into empty objects.
+    data = job_data,
     finishedAt = finished_at,
     error = error_msg
   })
@@ -689,7 +694,9 @@ export class RedisAdapter implements Adapter {
       return null
     }
 
-    return JSON.parse(result as string)
+    const { data, acquiredAt } = JSON.parse(result as string) as { data: string; acquiredAt: number }
+
+    return { ...JSON.parse(data), acquiredAt }
   }
 
   async completeJob(jobId: string, queue: string, removeOnComplete?: JobRetention): Promise<void> {
@@ -785,7 +792,9 @@ export class RedisAdapter implements Adapter {
       return null
     }
 
-    return JSON.parse(result as string)
+    const record = JSON.parse(result as string) as Omit<JobRecord, 'data'> & { data: string }
+
+    return { ...record, data: JSON.parse(record.data) as JobData }
   }
 
   push(jobData: JobData): Promise<PushResult | void> {

tests/adapter.spec.ts

@@ -416,6 +416,54 @@ test.group('Adapter | Redis', (group) => {
     const size = await adapter.sizeOf(queue)
     assert.equal(size, 1)
   })
+
+  test('popFrom should preserve an empty array payload instead of coercing it to an object', async ({
+    assert,
+  }) => {
+    const adapter = new RedisAdapter(connection)
+    const queue = 'empty-array-payload-queue'
+
+    try {
+      await adapter.pushOn(queue, {
+        id: 'empty-array-uuid-1',
+        name: 'TestJob',
+        payload: [],
+        attempts: 0,
+      })
+
+      await adapter.pushOn(queue, {
+        id: 'empty-array-uuid-2',
+        name: 'TestJob',
+        payload: {
+          empty: [],
+          names: ['Alice', 'Bob'],
+          deep: {
+            arr: [],
+            obj: {},
+          }
+        },
+        attempts: 0,
+      })
+
+      const simple = (await adapter.popFrom(queue))!
+      const nested = (await adapter.popFrom(queue))!
+
+      assert.equal(simple.id, 'empty-array-uuid-1')
+      assert.isArray(simple.payload)
+      assert.lengthOf(simple.payload as unknown[], 0)
+
+      assert.deepEqual(nested.payload, {
+        empty: [],
+        names: ['Alice', 'Bob'],
+        deep: {
+          arr: [],
+          obj: {},
+        },
+      })
+    } finally {
+      await adapter.destroy()
+    }
+  })
 })
 
 test.group('Adapter | Knex (SQLite)', (group) => {