How to use Sequelize with a UNIX domain socket

gistfile1.js

var sequelize = new Sequelize('postgres:/tmp');

var CM = sequelize.transactionManager.ConnectorManager;
sequelize.transactionManager.ConnectorManager = function (sequelize, config) {
    var cm = new CM(sequelize, config);
    cm.pg.defaults.database = 'database_name';
    return cm;
}

sequelize.getQueryInterface().QueryGenerator
    .databaseConnectionUri = function () { return '/tmp'; }

It's a lot simpler if you set the host in the options object and use null for both username and password:

var sequelize = new Sequelize(databaseName, null, null, {
	host: '/tmp', // or /var/run/postgresql
	dialect: 'postgres',
});

See: sequelize/sequelize#1591