1 files changed, 49 insertions, 0 deletions
diff --git a/jstests/core/query/count/count.js b/jstests/core/query/count/count.js
new file mode 100644
index 00000000000..76b858c17b9
--- /dev/null
+++ b/jstests/core/query/count/count.js
@@ -0,0 +1,49 @@
+/**
+ * Tests that count() in shell takes query.
+ *
+ * @tags: [
+ *     requires_fastcount,
+ *     assumes_against_mongod_not_mongos,
+ *     # Reliance on the $where operator
+ *     requires_scripting,
+ * ]
+ */
+
+(function() {
+"use strict";
+
+const collNamePrefix = 'jstests_count_';
+let collCount = 0;
+
+let coll = db.getCollection(collNamePrefix + collCount++);
+coll.drop();
+assert.commandWorked(coll.insert([{_id: 1, i: 1}, {_id: 2, i: 2}]));
+assert.eq(1, coll.find({i: 1}).count());
+assert.eq(1, coll.count({i: 1}));
+assert.eq(2, coll.find().count());
+assert.eq(2, coll.find(undefined).count());
+assert.eq(2, coll.find(null).count());
+assert.eq(2, coll.count());
+
+coll = db.getCollection(collNamePrefix + collCount++);
+coll.drop();
+assert.commandWorked(coll.createIndex({b: 1, a: 1}));
+assert.commandWorked(coll.insert({a: true, b: false}));
+assert.eq(1, coll.find({a: true, b: false}).count());
+assert.eq(1, coll.find({b: false, a: true}).count());
+
+coll = db.getCollection(collNamePrefix + collCount++);
+coll.drop();
+assert.commandWorked(coll.createIndex({b: 1, a: 1, c: 1}));
+assert.commandWorked(coll.insert({a: true, b: false}));
+
+assert.eq(1, coll.find({a: true, b: false}).count());
+assert.eq(1, coll.find({b: false, a: true}).count());
+
+// Make sure that invalid options passed into the shell count helper generate errors.
+assert.eq(assert.throws(() => coll.count({}, {random: true})).code, 40415);
+
+// Test that a string passed into count will be converted into a $where clause.
+assert.eq(1, coll.count("this.a"));
+assert.eq(0, coll.count("this.b"));
+})();