createQueue should not throw if it exists (#478)

* createQueue() should not throw if queue already exists

* 10.0.4 versioning

* update readme [skip ci]

README.md

@@ -25,6 +25,12 @@ async function readme() {
     console.log(`received job ${job.id} with data ${JSON.stringify(job.data)}`)
   })
 }
+
+readme()
+  .catch(err => {
+    console.log(err)
+    process.exit(1)
+  })
 ```
 
 pg-boss is a job queue built in Node.js on top of PostgreSQL in order to provide background processing and reliable asynchronous execution to Node.js applications.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "pg-boss",
-  "version": "10.0.3",
+  "version": "10.0.4",
   "description": "Queueing jobs in Postgres from Node.js like a boss",
   "main": "./src/index.js",
   "engines": {

src/plans.js

@@ -226,8 +226,10 @@ function createQueueFunction (schema) {
     $$
     DECLARE
       table_name varchar := 'j' || encode(sha224(queue_name::bytea), 'hex');
+      queue_created_on timestamptz;
     BEGIN
 
+      WITH q as (
       INSERT INTO ${schema}.queue (
         name,
         policy,
@@ -249,7 +251,15 @@ function createQueueFunction (schema) {
         (options->>'retentionMinutes')::int,
         options->>'deadLetter',
         table_name
-      );
+      )
+      ON CONFLICT DO NOTHING
+      RETURNING created_on
+      )
+      SELECT created_on into queue_created_on from q;
+
+      IF queue_created_on IS NULL THEN
+        RETURN;
+      END IF;
 
       EXECUTE format('CREATE TABLE ${schema}.%I (LIKE ${schema}.job INCLUDING DEFAULTS)', table_name);
       

test/queueTest.js

@@ -9,6 +9,14 @@ describe('queues', function () {
     await boss.createQueue(queue)
   })
 
+  it('createQueue should work if queue already exists', async function () {
+    const boss = this.test.boss = await helper.start({ ...this.test.bossConfig, noDefault: true })
+    const queue = this.test.bossConfig.schema
+
+    await boss.createQueue(queue)
+    await boss.createQueue(queue)
+  })
+
   it('should reject a queue with invalid characters', async function () {
     const boss = this.test.boss = await helper.start({ ...this.test.bossConfig, noDefault: true })
     const queue = `*${this.test.bossConfig.schema}`

test/readme.js

@@ -11,7 +11,6 @@ async function readme () {
 
   const queue = 'readme-queue'
 
-  await boss.deleteQueue(queue)
   await boss.createQueue(queue)
 
   const id = await boss.send(queue, { arg1: 'read me' })
@@ -27,3 +26,7 @@ async function readme () {
 }
 
 readme()
+  .catch(err => {
+    console.log(err)
+    process.exit(1)
+  })