From a894f822c2bc9e4970e7c6e3f0b56c4bdf5168a7 Mon Sep 17 00:00:00 2001
From: Adam C Hamlin <achamlin@gmail.com>
Date: Tue, 21 Feb 2023 21:54:59 -0500
Subject: [PATCH] fix: limit 1 active singleton queue job

---
 docs/readme.md    |  4 ++--
 src/plans.js      | 11 +++++++++++
 test/fetchTest.js | 24 ++++++++++++++++++++++++
 3 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/docs/readme.md b/docs/readme.md
index 6a61d0b0..1e9eb3e2 100644
--- a/docs/readme.md
+++ b/docs/readme.md
@@ -559,7 +559,7 @@ Available in constructor as a default, or overridden in send.
 
 * **singletonKey** string
 
-  Only allows 1 job (within the same name) to be queued or active with the same singletonKey.
+  Allows a max of 1 job (with the same name and singletonKey) to be queued or active.
 
   ```js
   boss.send('my-job', {}, {singletonKey: '123'}) // resolves a jobId
@@ -570,7 +570,7 @@ Available in constructor as a default, or overridden in send.
 
   * **useSingletonQueue** boolean
 
-  When used in conjunction with singletonKey, only allows 1 job (within the same name) to be queued with the same singletonKey.
+  When used in conjunction with singletonKey, allows a max of 1 job to be queued and a max of 1 job to be active.
 
   ```js
   boss.send('my-job', {}, {singletonKey: '123', useSingletonQueue: true}) // resolves a jobId
diff --git a/src/plans.js b/src/plans.js
index bb7b2760..a8b0d031 100644
--- a/src/plans.js
+++ b/src/plans.js
@@ -358,6 +358,17 @@ function fetchNextJob (schema) {
       WHERE state < '${states.active}'
         AND name LIKE $1
         AND startAfter < now()
+        AND NOT (
+          singletonKey IS NOT NULL
+          AND singletonKey LIKE '${SINGLETON_QUEUE_KEY_ESCAPED}%'
+          AND EXISTS (
+            SELECT *
+            FROM ${schema}.job active_job
+            WHERE active_job.state = '${states.active}'
+              AND active_job.name = name
+              AND active_job.singletonKey = singletonKey
+          )
+        )
       ORDER BY priority desc, createdOn, id
       LIMIT $2
       FOR UPDATE SKIP LOCKED
diff --git a/test/fetchTest.js b/test/fetchTest.js
index d2a9a858..3a25d482 100644
--- a/test/fetchTest.js
+++ b/test/fetchTest.js
@@ -121,4 +121,28 @@ describe('fetch', function () {
     assert(job.startedon === undefined)
     assert.strictEqual(calledCounter, 2)
   })
+
+  it('should not fetch singleton queue job if there is already an active one', async function () {
+    const boss = this.test.boss = await helper.start(this.test.bossConfig)
+    const queue = this.test.bossConfig.schema
+    const jobOptions = { singletonKey: 'singleton_queue_active_test', useSingletonQueue: true }
+    const sendArgs = [queue, {}, jobOptions]
+
+    const publish1 = await boss.send(...sendArgs)
+    const fetch1 = await boss.fetch(queue)
+    assert(publish1)
+    assert(fetch1)
+
+    const publish2 = await boss.send(...sendArgs)
+    assert(publish2)
+    // Job 1 still active, can't fetch job 2
+    const fetch2 = await boss.fetch(queue)
+    assert(fetch2 === null)
+
+    await boss.complete(fetch1.id)
+    // Job 1 no longer active, should be able to fetch
+    const retryFetch2 = await boss.fetch(queue)
+    assert(retryFetch2)
+    assert(retryFetch2.id === publish2)
+  })
 })