Await SNS message publishing and replace queue purge test helper

This commit addresses intermittent failures in system tests related to SNS
message publishing. Adding console.log statements revealed 2 situations

- Test assertions were running before an item ingest message was published
- Calling `purgeQeue` did not appear to actually empty the SNS queue

This commit moves an await call to guarantee that messages are published to SNS
before trying to assert that they have been published and replaces a call to
`purgeQueue` will calling `receiveMessage` in a loop.

Author: jwalgran

src/lib/ingest.js

@@ -187,11 +187,11 @@ function updateLinksWithinRecord(record) {
   return record
 }
 
-export async function publishResultsToSns(results, topicArn) {
-  results.forEach((result) => {
+export function publishResultsToSns(results, topicArn) {
+  results.forEach(async (result) => {
     if (result.record && !result.error) {
       updateLinksWithinRecord(result.record)
     }
-    publishRecordToSns(topicArn, result.record, result.error)
+    await publishRecordToSns(topicArn, result.record, result.error)
   })
 }

tests/system/test-ingest.js

@@ -384,17 +384,35 @@ test('Ingest collection failure is published to post-ingest SNS topic', async (t
   t.is(attrs.recordType.Value, 'Collection')
 })
 
+async function emptyPostIngestQueue(t) {
+  // We initially tried calling
+  // await sqs().purgeQueue({ QueueUrl: postIngestQueueUrl }).promise()
+  // But at least one test would intermittently fail because of an additional
+  // message in the queue.
+  // The documentation for the purgeQueue method says:
+  //   "The message deletion process takes up to 60 seconds.
+  //    We recommend waiting for 60 seconds regardless of your queue's size."
+  let result
+  do {
+    // eslint-disable-next-line no-await-in-loop
+    result = await sqs().receiveMessage({
+      QueueUrl: t.context.postIngestQueueUrl,
+      WaitTimeSeconds: 1
+    }).promise()
+  } while (result.Message && result.Message.length > 0)
+}
+
 async function ingestCollectionAndPurgePostIngestQueue(t) {
-  const { ingestFixture, postIngestQueueUrl } = t.context
+  const { ingestFixture } = t.context
 
   const collection = await ingestFixture(
     'landsat-8-l1-collection.json',
     { id: randomId('collection') }
   )
 
-  // Purging the post-ingest queue ensures that subsequent calls to testPostIngestSNS
+  // Emptying the post-ingest queue ensures that subsequent calls to testPostIngestSNS
   // only see the message posted after the final ingest
-  await sqs().purgeQueue({ QueueUrl: postIngestQueueUrl }).promise()
+  await emptyPostIngestQueue(t)
 
   return collection
 }