onebeyond/generator-systemic

const R = require('ramda');
const Prepper = require('prepper');

module.exports = ({ prepper, transport } = {}) => {
  const prepperFn = prepper || Prepper;
  const { handlers } = prepperFn;

  const start = async ({ config, transports, pkg = { name: 'unknown' } }) => {
    const transportFn = transport || R.path([config.transport], transports);
    const finalConfig = R.merge({ include: [], exclude: [] }, config);
    const logger = new prepperFn.Logger({
      handlers: [
        new handlers.Merge({ package: pkg }),
        new handlers.Merge({ service: { env: process.env.SERVICE_ENV } }),
        new handlers.Process(),
        new handlers.System(),
        new handlers.Timestamp(),
        new handlers.Flatten(),
        new handlers.KeyFilter({ include: finalConfig.include, exclude: finalConfig.exclude }),
        new handlers.Unflatten(),
      ],
    }).on('message', event => {
      if (transportFn) transportFn(event);
    });

    return logger;
  };

  return { start };
};