1 files changed, 73 insertions, 0 deletions
diff --git a/jstests/noPassthrough/validate_multikey_failures.js b/jstests/noPassthrough/validate_multikey_failures.js
new file mode 100644
index 00000000000..893304b1ae3
--- /dev/null
+++ b/jstests/noPassthrough/validate_multikey_failures.js
@@ -0,0 +1,73 @@
+/**
+ * Test that validate detects and properly reports multikey inconsistencies.
+ */
+(function() {
+"use strict";
+
+const baseName = "validate_multikey_failures";
+const dbpath = MongoRunner.dataPath + baseName + "/";
+let conn = MongoRunner.runMongod({dbpath: dbpath});
+let coll = conn.getDB("test").getCollection("corrupt");
+
+const resetCollection = () => {
+    coll.drop();
+    coll.createIndex({"a.b": 1});
+};
+
+const disableMultikeyUpdate = () => {
+    assert.commandWorked(
+        conn.adminCommand({configureFailPoint: "skipUpdateIndexMultikey", mode: "alwaysOn"}));
+};
+
+const enableMultikeyUpdate = () => {
+    assert.commandWorked(
+        conn.adminCommand({configureFailPoint: "skipUpdateIndexMultikey", mode: "off"}));
+};
+
+// Test that multiple keys suggest index should be marked multikey.
+resetCollection();
+disableMultikeyUpdate();
+assert.commandWorked(coll.insert({a: {b: [1, 2]}}));
+enableMultikeyUpdate();
+let res = coll.validate();
+assert.commandWorked(res);
+assert(!res.valid);
+assert.eq(res.indexDetails["a.b_1"].errors.length, 1);
+assert(res.indexDetails["a.b_1"].errors[0].startsWith("Index a.b_1 is not multikey"));
+assert(res.indexDetails["a.b_1"].errors[0].includes("2 key(s)"));
+assert(checkLog.checkContainsWithAtLeastCountJson(conn, 7556100, {"indexName": "a.b_1"}, 1));
+assert(checkLog.checkContainsWithAtLeastCountJson(conn, 7556101, {"indexKey": {"a.b": 1}}, 1));
+assert(checkLog.checkContainsWithAtLeastCountJson(conn, 7556101, {"indexKey": {"a.b": 2}}, 1));
+
+// Test that a single-entry array suggests index should be marked multikey.
+resetCollection();
+disableMultikeyUpdate();
+assert.commandWorked(coll.insert({a: {b: [3]}}));
+enableMultikeyUpdate();
+res = coll.validate();
+assert.commandWorked(res);
+assert(!res.valid);
+assert.eq(res.indexDetails["a.b_1"].errors.length, 1);
+assert(res.indexDetails["a.b_1"].errors[0].startsWith("Index a.b_1 is not multikey"));
+assert(res.indexDetails["a.b_1"].errors[0].includes("1 key(s)"));
+assert(checkLog.checkContainsWithAtLeastCountJson(conn, 7556100, {"indexName": "a.b_1"}, 1));
+assert(checkLog.checkContainsWithAtLeastCountJson(conn, 7556101, {"indexKey": {"a.b": 3}}, 1));
+
+// Test that a mis-match in multikey paths should be marked multikey.
+resetCollection();
+assert.commandWorked(coll.insert({a: [{b: 4}, {b: 5}]}));
+disableMultikeyUpdate();
+assert.commandWorked(coll.insert({a: {b: [6]}}));
+enableMultikeyUpdate();
+res = coll.validate();
+assert.commandWorked(res);
+assert(!res.valid);
+assert.eq(res.indexDetails["a.b_1"].errors.length, 1);
+assert(res.indexDetails["a.b_1"].errors[0].startsWith(
+    "Index a.b_1 multikey paths do not cover a document"));
+assert(checkLog.checkContainsWithAtLeastCountJson(conn, 7556100, {"indexName": "a.b_1"}, 1));
+assert(checkLog.checkContainsWithAtLeastCountJson(conn, 7556101, {"indexKey": {"a.b": 6}}, 1));
+assert(checkLog.checkContainsWithAtLeastCountJson(conn, 5367500, {"index": "a.b_1"}, 1));
+
+MongoRunner.stopMongod(conn, null, {skipValidation: true});
+})();
+\ No newline at end of file