1 files changed, 52 insertions, 0 deletions
diff --git a/jstests/sharding/config_settings_schema.js b/jstests/sharding/config_settings_schema.js
new file mode 100644
index 00000000000..8039bdd2206
--- /dev/null
+++ b/jstests/sharding/config_settings_schema.js
@@ -0,0 +1,52 @@
+/**
+ * Tests that the schema on config.settings works as intended.
+ *
+ * @tags: [featureFlagConfigSettingsSchema, requires_fcv_62, does_not_support_stepdowns]
+ */
+(function() {
+'use strict';
+
+load("jstests/libs/feature_flag_util.js");
+
+var st = new ShardingTest({shards: 1, config: 2});
+
+let coll = st.config.settings;
+
+// Updates that violate schema are rejected
+// Chunk size too small
+assert.commandFailed(coll.update({_id: "chunksize"}, {$set: {value: -1}}, {upsert: true}));
+// Chunk size must be a number
+assert.commandFailed(coll.update({_id: "chunksize"}, {$set: {value: "string"}}, {upsert: true}));
+// Chunk size too big
+assert.commandFailed(coll.update({_id: "chunksize"}, {$set: {value: 5000}}, {upsert: true}));
+// Extra field in chunk size doc
+assert.commandFailed(
+    coll.update({_id: "chunksize"}, {$set: {value: 100, extraField: 10}}, {upsert: true}));
+// Not a valid setting _id
+assert.commandFailed(coll.update({_id: "notARealSetting"}, {$set: {value: 10}}, {upsert: true}));
+
+// Updates that match the schema are accepted
+// No schema is enforced for balancer, autosplit, and ReadWriteConcernDefaults
+assert.commandWorked(coll.update({_id: "balancer"}, {$set: {anything: true}}, {upsert: true}));
+assert.commandWorked(coll.update({_id: "autosplit"}, {$set: {anything: true}}, {upsert: true}));
+assert.commandWorked(
+    coll.update({_id: "ReadWriteConcernDefaults"}, {$set: {anything: true}}, {upsert: true}));
+// Schema enforces chunksize to be a number (not an int), so doubles will be accepted and the
+// balancer will fail until a correct value is set
+assert.commandWorked(coll.update({_id: "chunksize"}, {$set: {value: 3.5}}, {upsert: true}));
+// Valid integer value
+assert.commandWorked(coll.update({_id: "chunksize"}, {$set: {value: 5}}, {upsert: true}));
+
+// User cannot change schema on config.settings
+assert.commandFailedWithCode(
+    st.s.getDB("config").runCommand({"collMod": "settings", "validator": {}}),
+    ErrorCodes.InvalidOptions);
+assert.commandFailedWithCode(
+    st.s.getDB("config").runCommand({"collMod": "settings", "validationLevel": "off"}),
+    ErrorCodes.InvalidOptions);
+assert.commandFailedWithCode(
+    st.s.getDB("config").runCommand({"collMod": "settings", "validationAction": "warn"}),
+    ErrorCodes.InvalidOptions);
+
+st.stop();
+})();