logger-steps/cjs/index.js

Group log messages and send them in one batch to the logger of your choize

"use strict";

exports.__esModule = true;
var levels = ["error", "warn", "log", "info", "debug"];

/**
 * Returns an object with the same interface the Logger has.
 * The difference is that instead of inmediatelly send the log messages to the
 * target output, messages are collected into a trace and then otputed all at the
 * same time when a trace flush is triggered.
 * You should peform a flush when you finish the trace, but in case you don't do
 * an automatic flush is peformed after a configurable timeout.
 * Please note that you should allways call the flush method.
 * Not doing it and relying to the automatic flush could cause unexpected behaviors and performance problems.
 *
 * @param {any} logger  the logger to use to flush the trace
 * @param {number} secs the number of seconds before triggering  an automatic flush
 * @return {Object} tracer - the tracer object containing the usual methods the logger has
 * @return {function} tracer.flush - sends the complete trace to the provided logger
*/
var tracer = function tracer(logger) {
  var tracename = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : "Steps";
  var secs = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : 30;

  secs = typeof secs === "number" ? secs : 30;
  var levelName = "debug";
  var level = 4;
  var steps = [tracename + ": \n"];
  var API = {};
  var flushTimeout = resetFlushTimeout();

  /**
   * Flushes the current trace to the logger.
   * If this is an automatic flush, it adds a warning to the trace because this should never happen
  */
  function flush(isAutomaticFlush) {

    if (isAutomaticFlush) {
      API.warn("Automatic trace flush", "This usually means an error on the process using the trace or a bad trace-API usage");
    }
    logger[levelName].apply(logger, steps);
    clearTimeout(flushTimeout);
  }

  function resetFlushTimeout() {

    flushTimeout && clearTimeout(flushTimeout);
    flushTimeout = setTimeout(flush, secs * 1000, true);
    return flushTimeout;
  }

  /**
   * Registers a log message in the trace.
   * If the logging level has more priority than the current one (lower name)
   * then the whole trace level is set to that logging level
   */
  var handleLogMessage = function handleLogMessage(lvlName, lvl, title) {
    for (var _len = arguments.length, rest = Array(_len > 3 ? _len - 3 : 0), _key = 3; _key < _len; _key++) {
      rest[_key - 3] = arguments[_key];
    }

    var step = { title: title };
    if (rest.length > 0) {
      step.details = rest.length === 1 ? rest[0] : rest;
    }
    steps.push(step);
    if (lvl < level) {
      level = lvl;
      levelName = lvlName;
    }
    resetFlushTimeout();
  };

  /**
   * We bind flush to false so whatever is passed is ignored and
   * we do not erroneous flag the flush as automatic*/
  API.flush = flush.bind(API, false);
  /**
   * Build the rest of the API interface
  */
  return levels.reduce(function (api, name, lvl) {
    api[name] = handleLogMessage.bind(api, name, lvl);
    return api;
  }, API);
};

exports.default = tracer;
module.exports = exports["default"];