Transport

All transports for churchill should extend this base class.

npm install @churchill/transport

Implementing own transport

A transport is a class with a log method. Log method arguments are info, output and logger, where info is the object with logged message, output is formatted message by the global format function and logger is the instance that logged the message. See implementation of transports for examples.

const { Transport } = require("@churchill/transport");

// Here is a simple transport that logs to stdout and has option to provide a prefix
// Note: it does not correcly handle stream backpressure
class CustomTransport extends Transport {
  constructor(opts) {
    super(opts);
    const { prefix = "" } = opts;
    this.prefix = prefix;
  }

  /**
   * Log a Message
   * @param {Object} info Message
   * @param {*} [output] Output of the global formatting function
   * @param {Logger} logger Logger
   */
  async log(info, output, logger) {
    const out = this.format(info, output, logger);
    const prefixed = custom ? `${this.prefix}${out}` : out;
    // Transport is also an EventEmitter, so you can emit events
    if (custom) {
      this.emit("some-event", info);
    }
    process.stdout.write(prefixed); // naively log to console
  }
}

// It is recommented to provide a factory to create your logger
CustomTransport.create = opts => {
  return new CustomTransport(opts);
};

module.exports = CustomTransport;

Publishing your transport

By convention you should name your transport as churchill-<transport>.