From b44bcc8aba3e8cf386618055f796d1904d3ba0dd Mon Sep 17 00:00:00 2001
From: Xuerui Fa <xuerui.fa@mongodb.com>
Date: Mon, 1 Jun 2020 11:58:13 -0400
Subject: SERVER-48514: Separate testing 'called' and 'successful' fields for
 serverStatus election metrics

(cherry picked from commit 1a79855014361b5938322549758a89c1ec75e792)
---
 jstests/replsets/libs/election_metrics.js | 28 ++++++++++++++++++++--------
 jstests/replsets/stepup.js                |  3 ++-
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/jstests/replsets/libs/election_metrics.js b/jstests/replsets/libs/election_metrics.js
index 36307b2117e..423aa30a678 100644
--- a/jstests/replsets/libs/election_metrics.js
+++ b/jstests/replsets/libs/election_metrics.js
@@ -19,18 +19,30 @@ function verifyServerStatusElectionReasonCounterValue(electionMetrics, fieldName
 /**
  * Verifies that the given election reason counter is incremented in the way we expect in the
  * 'electionMetrics' serverStatus section.
+ *
+ * The 'expectedNumSuccessful' field should be passed in when we need to distinguish between how
+ * many times an election was called and how many times an election was successful.
  */
-function verifyServerStatusElectionReasonCounterChange(
-    initialElectionMetrics, newElectionMetrics, fieldName, expectedIncrement) {
+function verifyServerStatusElectionReasonCounterChange(initialElectionMetrics,
+                                                       newElectionMetrics,
+                                                       fieldName,
+                                                       expectedNumCalled,
+                                                       expectedNumSuccessful = undefined) {
+    // If 'expectedNumSuccessful' is not passed in, we assume that the 'successful' field is equal
+    // to the 'called' field.
+    if (!expectedNumSuccessful) {
+        expectedNumSuccessful = expectedNumCalled;
+    }
+
     const initialField = initialElectionMetrics[fieldName];
     const newField = newElectionMetrics[fieldName];
-    assert.eq(initialField["called"] + expectedIncrement,
+    assert.eq(initialField["called"] + expectedNumCalled,
               newField["called"],
-              `expected the 'called' field of '${fieldName}' to increase by ${expectedIncrement}`);
-    assert.eq(
-        initialField["successful"] + expectedIncrement,
-        newField["successful"],
-        `expected the 'successful' field of '${fieldName}' to increase by ${expectedIncrement}`);
+              `expected the 'called' field of '${fieldName}' to increase by ${expectedNumCalled}`);
+    assert.eq(initialField["successful"] + expectedNumSuccessful,
+              newField["successful"],
+              `expected the 'successful' field of '${fieldName}' to increase by ${
+                  expectedNumSuccessful}`);
 }
 
 /**
diff --git a/jstests/replsets/stepup.js b/jstests/replsets/stepup.js
index c7062a6b4f0..1c52f68e98a 100644
--- a/jstests/replsets/stepup.js
+++ b/jstests/replsets/stepup.js
@@ -55,7 +55,8 @@ const newSecondaryStatus = assert.commandWorked(secondary.adminCommand({serverSt
 verifyServerStatusElectionReasonCounterChange(initialSecondaryStatus.electionMetrics,
                                               newSecondaryStatus.electionMetrics,
                                               "stepUpCmd",
-                                              numStepUpCmds);
+                                              numStepUpCmds, /* expectedNumCalled */
+                                              1 /* expectedNumSuccessful */);
 verifyServerStatusElectionReasonCounterChange(initialSecondaryStatus.electionMetrics,
                                               newSecondaryStatus.electionMetrics,
                                               "priorityTakeover",
-- 
cgit v1.2.1