From 56de72881f50d709b5898c567f646097f7af2694 Mon Sep 17 00:00:00 2001
From: Pierlauro Sciarelli <pierlauro.sciarelli@mongodb.com>
Date: Tue, 8 Sep 2020 14:03:30 +0000
Subject: SERVER-50780 Improve cache.collections consistency check in
 ShardingTest hook

---
 .../check_uuids_consistent_across_cluster.js              | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/jstests/libs/override_methods/check_uuids_consistent_across_cluster.js b/jstests/libs/override_methods/check_uuids_consistent_across_cluster.js
index 10f7a8a14da..800e3f005b8 100644
--- a/jstests/libs/override_methods/check_uuids_consistent_across_cluster.js
+++ b/jstests/libs/override_methods/check_uuids_consistent_across_cluster.js
@@ -151,10 +151,17 @@ ShardingTest.prototype.checkUUIDsConsistentAcrossCluster = function() {
                     assert.commandWorked(shardConn.adminCommand(
                         {_flushRoutingTableCacheUpdates: ns, syncFromConfig: false}));
 
-                    const actualConfigMetadata =
-                        shardConn.getDB("config").getCollection("cache.collections").find({
-                            "_id": ns
-                        })[0];
+                    let actualConfigMetadata = shardConn.getDB("config")
+                                                   .getCollection("cache.collections")
+                                                   .find({"_id": ns})
+                                                   .toArray();
+                    assert.eq(
+                        actualConfigMetadata.length,
+                        1,
+                        "Incorrect number of entries in 'cache.collections' have been found for collection '" +
+                            ns + "' on node " + shardConn);
+                    actualConfigMetadata = actualConfigMetadata[0];
+
                     assert.eq(authoritativeCollMetadata.collInfo.uuid,
                               actualConfigMetadata.uuid,
                               "authoritative collection info on config server: " +
-- 
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