From 707040656c31cd3dcd5cb75cd960b638d328f2d9 Mon Sep 17 00:00:00 2001
From: pgayvallet <pierre.gayvallet@elastic.co>
Date: Wed, 6 May 2020 09:23:39 +0200
Subject: [PATCH 1/2] fix flaky test

---
 .../metrics/integration_tests/server_collector.test.ts      | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/core/server/metrics/integration_tests/server_collector.test.ts b/src/core/server/metrics/integration_tests/server_collector.test.ts
index dd5c256cf1600..397a1c8d76750 100644
--- a/src/core/server/metrics/integration_tests/server_collector.test.ts
+++ b/src/core/server/metrics/integration_tests/server_collector.test.ts
@@ -185,18 +185,18 @@ describe('ServerMetricsCollector', () => {
     let metrics = await collector.collect();
     expect(metrics.concurrent_connections).toEqual(0);
 
-    sendGet('/').end(() => null);
+    const res1 = sendGet('/').then(res => res);
     await waitForHits(1);
     metrics = await collector.collect();
     expect(metrics.concurrent_connections).toEqual(1);
 
-    sendGet('/').end(() => null);
+    const res2 = sendGet('/').then(res => res);
     await waitForHits(2);
     metrics = await collector.collect();
     expect(metrics.concurrent_connections).toEqual(2);
 
     waitSubject.next('go');
-    await delay(requestWaitDelay);
+    await Promise.all([res1, res2]);
     metrics = await collector.collect();
     expect(metrics.concurrent_connections).toEqual(0);
   });

From 22269a58f6449877755179381ac09736ee2cfc2e Mon Sep 17 00:00:00 2001
From: pgayvallet <pierre.gayvallet@elastic.co>
Date: Wed, 6 May 2020 10:21:04 +0200
Subject: [PATCH 2/2] add comment on supertest behavior

---
 .../server/metrics/integration_tests/server_collector.test.ts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/core/server/metrics/integration_tests/server_collector.test.ts b/src/core/server/metrics/integration_tests/server_collector.test.ts
index 397a1c8d76750..3b982a06cf06c 100644
--- a/src/core/server/metrics/integration_tests/server_collector.test.ts
+++ b/src/core/server/metrics/integration_tests/server_collector.test.ts
@@ -185,6 +185,10 @@ describe('ServerMetricsCollector', () => {
     let metrics = await collector.collect();
     expect(metrics.concurrent_connections).toEqual(0);
 
+    // supertest requests are executed when calling `.then` (or awaiting them).
+    // however in this test we need to send the request now and await for it later in the code.
+    // also using `.end` is not possible as it would execute the request twice.
+    // so the only option is this noop `.then`.
     const res1 = sendGet('/').then(res => res);
     await waitForHits(1);
     metrics = await collector.collect();