mongodb/jstests/multiVersion/copydb_helper.js

// SERVER-36438 Ensure the 4.2 copyDatabase() shell helper still successfully executes the copyDB
// command on a 4.0 server, now that the copyDB command has been removed as of 4.2.
(function() {
    "use strict";
    const oldVersion = "4.0";

    let runTest = function(useAuth) {
        let conn;
        if (useAuth) {
            conn = MongoRunner.runMongod({auth: "", binVersion: oldVersion});
        } else {
            conn = MongoRunner.runMongod({binVersion: oldVersion});
        }

        let fromDB = conn.getDB("copydb2-test-a");
        let toDB = conn.getDB("copydb2-test-b");
        let adminDB = conn.getDB("admin");

        if (useAuth) {
            adminDB.createUser({user: "root", pwd: "root", roles: ["root"]});
            adminDB.auth("root", "root");
            fromDB.createUser({
                user: "chevy",
                pwd: "chase",
                roles: ["read", {role: "readWrite", db: toDB._name}]
            });
        }

        assert.commandWorked(fromDB.foo.insert({a: 1}));
        assert.commandWorked(fromDB.foo.createIndex({a: 1}));

        if (useAuth) {
            assert.commandWorked(toDB.getSiblingDB("admin").logout());
            fromDB.auth("chevy", "chase");
        }

        assert.eq(1, fromDB.foo.count());
        assert.eq(0, toDB.foo.count());

        assert.commandWorked(fromDB.copyDatabase(fromDB._name, toDB._name));
        assert.eq(1, fromDB.foo.count());
        assert.eq(1, toDB.foo.count());
        assert.eq(fromDB.foo.getIndexes().length, toDB.foo.getIndexes().length);
        MongoRunner.stopMongod(conn);
    };

    runTest(/*useAuth*/ false);

    // Authenticating as multiple users on multiple databases results in an error.
    if (!jsTest.options().auth) {
        runTest(/*useAuth*/ true);
    }
})();