SERVER-47798 ismaster.js tests should ensure ismaster field is a boolean

(cherry picked from commit d5d0401e518beab5b659c1a01a092286f8a9c792)
(cherry picked from commit 9c1ce38d7c87f625be1c2d5d7f5a6b709ebfb72e)

1 files changed, 4 insertions, 1 deletions

diff --git a/jstests/sharding/ismaster.js b/jstests/sharding/ismaster.js
index 47dff297e96..2d5cea7b586 100644
--- a/jstests/sharding/ismaster.js
+++ b/jstests/sharding/ismaster.js
@@ -1,3 +1,4 @@
+"use strict";
 var st = new ShardingTest({shards: 1, mongos: 1});
 var res = st.s0.getDB("admin").runCommand("ismaster");
 // check that the fields that should be there are there and have proper values
@@ -5,7 +6,8 @@ assert(res.maxBsonObjectSize && isNumber(res.maxBsonObjectSize) && res.maxBsonOb
        "maxBsonObjectSize possibly missing:" + tojson(res));
 assert(res.maxMessageSizeBytes && isNumber(res.maxMessageSizeBytes) && res.maxBsonObjectSize > 0,
        "maxMessageSizeBytes possibly missing:" + tojson(res));
-assert(res.ismaster, "ismaster missing or false:" + tojson(res));
+assert.eq("boolean", typeof res.ismaster, "ismaster field is not a boolean" + tojson(res));
+assert(res.ismaster === true, "ismaster field is false" + tojson(res));
 assert(res.localTime, "localTime possibly missing:" + tojson(res));
 assert(res.msg && res.msg == "isdbgrid", "msg possibly missing or wrong:" + tojson(res));
 var unwantedFields = [
@@ -26,6 +28,7 @@ var unwantedFields = [
 ];
 // check that the fields that shouldn't be there are not there
 var badFields = [];
+var field;
 for (field in res) {
     if (!res.hasOwnProperty(field)) {
         continue;