1 files changed, 21 insertions, 0 deletions
diff --git a/jstests/core/id_partial_projection.js b/jstests/core/id_partial_projection.js
new file mode 100644
index 00000000000..7affbcfb875
--- /dev/null
+++ b/jstests/core/id_partial_projection.js
@@ -0,0 +1,21 @@
+/**
+ * Tests partial inclusion/exclusion of _id.
+ * See SERVER-7502 for details.
+ */
+(function() {
+"use strict";
+
+const coll = db.id_partial_projection;
+coll.drop();
+
+assert.commandWorked(coll.insert({_id: {a: 1, b: 1}, otherField: 1}));
+assert.commandWorked(coll.insert({_id: 3, otherField: 2}));
+
+assert.eq(coll.find({}, {"_id": 1}).toArray(), [{_id: {a: 1, b: 1}}, {_id: 3}]);
+assert.eq(coll.find({}, {"_id.a": 1}).toArray(), [{_id: {a: 1}}, {}]);
+assert.eq(coll.find({}, {"_id.b": 1}).toArray(), [{_id: {b: 1}}, {}]);
+
+assert.eq(coll.find({}, {"_id.a": 0}).toArray(),
+          [{_id: {b: 1}, otherField: 1}, {_id: 3, otherField: 2}]);
+assert.eq(coll.find({}, {_id: 0}).toArray(), [{otherField: 1}, {otherField: 2}]);
+})();