Node.js and node-oracle: Problems connecting to Oracle database

I am writing a Node.js application that pulls data from an Oracle database. The DBA recently migrated the database to another machine, and everything broke.

I've tried re-creating the tnsnames.ora and sqlnet.ora files. I'm fairly sure that they are correct, because sqlplus can connect to the service just fine. But node-oracle keeps reporting the error: "ORA-12154: TNS:could not resolve the connect identifier specified".

This is inexplicable to me. It seems to me that if I have my ORACLE_HOME environment variable set, then both node-oracle and sqlplus should function identically. What am I doing wrong?

I've tried switching to node-db-oracle instead, but it reports the same problem. I'm stumped.

EDIT: This is how I connect:

    database = new oracle.Database({
            hostname: Preferences["oracle_host"],  // FQDN of the database
            port: Preferences["oracle_port"],
            user: Credentials["oracle_login"],
            password: Credentials["oracle_password"],
            database: Preferences["oracle_database"]
        });

    connection = database.connect(function(error) {
            if(error) {
                Utilities.logger.error(error);
            }
            else {
                Utilities.logger.info("Connected to Oracle database " + Preferences["oracle_host"]);    
                if(callback) callback.call(this, collection, options);
                connection = this;
            }

        });