SERVER-26726 Check number of arguments for createIndex, createIndexes and ensureIndex shell commands

Author: laplab

jstests/core/create_index_helper_validation.js

@@ -0,0 +1,29 @@
+// Tests that helper functions for creating indexes check the number of arguments passed.
+
+(function() {
+"use strict";
+
+const coll = db.create_index_helper_validation;
+coll.drop();
+
+assert.throws(() => coll.createIndexes(
+                  /* keys */[{a: 1}],
+                  /* options */ {},
+                  /* commitQuorum */ "majority",
+                  {background: true},
+                  {unique: true}));
+
+assert.throws(() => coll.createIndex(
+                  /* keys */ {a: 1},
+                  /* options */ {},
+                  /* commitQuorum */ "majority",
+                  {background: true},
+                  {unique: true}));
+
+assert.throws(() => coll.ensureIndex(
+                  /* keys */ {a: 1},
+                  /* options */ {},
+                  /* commitQuorum */ "majority",
+                  {background: true},
+                  {unique: true}));
+}());

src/mongo/shell/collection.js

@@ -639,10 +639,18 @@ DBCollection.prototype._indexSpec = function(keys, options) {
 };
 
 DBCollection.prototype.createIndex = function(keys, options, commitQuorum) {
+    if (arguments.length > 3) {
+        throw new Error("createIndex accepts up to 3 arguments");
+    }
+
     return this.createIndexes([keys], options, commitQuorum);
 };
 
 DBCollection.prototype.createIndexes = function(keys, options, commitQuorum) {
+    if (arguments.length > 3) {
+        throw new Error("createIndexes accepts up to 3 arguments");
+    }
+
     if (!Array.isArray(keys)) {
         throw new Error("createIndexes first argument should be an array");
     }
@@ -664,6 +672,10 @@ DBCollection.prototype.createIndexes = function(keys, options, commitQuorum) {
 };
 
 DBCollection.prototype.ensureIndex = function(keys, options) {
+    if (arguments.length > 2) {
+        throw new Error("ensureIndex accepts up to 2 arguments");
+    }
+
     var result = this.createIndex(keys, options);
 
     if (this.getMongo().writeMode() != "legacy") {