agnostic_config_file.js

var applicationConfig = {
    local: {
        server: {
            host: 'localhost',
            port: 8889,
            clientSecret: 'abcd',
            callbackURL: 'def'
        }
    },
    development: {
        server: {
            host: 'localhost',
            port: 8889,
            clientSecret: 'abcd',
            callbackURL: 'def'
        }
    },
    testing: {
        server: {
            host: 'localhost',
            port: 8889,
            clientSecret: 'abcd',
            callbackURL: 'def'
        }
    },
    production: {
        server: {
            host: 'localhost',
            port: 8889,
            clientSecret: 'abcd',
            callbackURL: 'def'
        }
    },
};

if (typeof(global) === 'object' && typeof(window) === 'undefined') {
  module.exports = applicationConfig[process.env.NODE_ENV || 'SOME_ENVIRONMENT'];
} else {
  module.exports = applicationConfig['testing'];
}