Logger

logger.js

const util = require('util');

const R = require('ramda');
const chalk = require('chalk');
const jsondiffpatch = require('jsondiffpatch');

const toJson = require('./to-json');

let prefix;
let coloredOutput = false;

if (
  process.env.NODE_ENV === 'development' ||
  process.env.NODE_ENV === 'test' ||
  process.env.NODE_ENV === 'script' ||
  !process.env.NODE_ENV
) {
  chalk.enabled = true;
  // eslint-disable-next-line global-require
  prefix = require('./global-prefix').getProcessWideLogPrefix();
  coloredOutput = true;
} else {
  chalk.enabled = false;
}

const createCustomChalk = (chalkFunc, ...chalkArgs) => (...args) => {
  if (chalkFunc === 'hex') {
    return chalk[chalkFunc](R.head(chalkArgs))(...args);
  }
  return chalk[chalkFunc](...args);
};

const createMsg = (type = '', modulePrefixStr = '') => (chalkFuncName, ...chalkArgs) => {
  // for "hex" we expect first argument to be actual hex color
  const args = chalkFuncName === 'hex' ? R.tail(chalkArgs) : chalkArgs;

  const stringifiedArgs = args.map(arg => {
    if (arg instanceof Error) {
      const remainingProps = R.omit(['message', 'stack'], arg);
      return R.isEmpty(remainingProps)
        ? `${arg.message}\n${arg.stack}`
        : `${arg.message}\n${arg.stack}\nAdditional error props: ${toJson(remainingProps)}`;
    }
    const logStr = typeof arg === 'object' ? toJson(arg) : arg;
    return logStr;
  });

  const typePrefix = type ? `[${type}]` : '';
  const modulePrefix = modulePrefixStr ? `[${modulePrefixStr}]` : '';
  const globalPrefix = prefix ? `[${prefix}]` : '';

  const customChalk = createCustomChalk(chalkFuncName, ...chalkArgs);

  if (modulePrefix) {
    return prefix
      ? customChalk(`${globalPrefix}${typePrefix}${modulePrefix}`, ...stringifiedArgs)
      : customChalk(`${typePrefix}${modulePrefix}`, ...stringifiedArgs);
  }

  if (globalPrefix) {
    return customChalk(`${globalPrefix}${typePrefix}`, ...stringifiedArgs);
  }

  return customChalk(typePrefix, ...stringifiedArgs);
};

let debugAlternateCounter = 0;

/* eslint-disable no-console */
const log = (modulePrefix = '') => ({
  error: (...args) => console.error(createMsg('error', modulePrefix)('red', ...args)),
  exception: (...args) => console.error(createMsg('error', modulePrefix)('red', ...args)),
  trace: (...args) => console.trace(createMsg('trace', modulePrefix)('red', ...args)),
  info: (...args) => console.info(createMsg('info', modulePrefix)('gray', ...args)),
  success: (...args) => console.log(createMsg('success', modulePrefix)('green', ...args)),
  done: (...args) => console.log(createMsg('success', modulePrefix)('green', ...args)),
  warn: (...args) => console.warn(createMsg('warn', modulePrefix)('yellow', ...args)),
  warnTrace: (...args) => console.trace(createMsg('warn', modulePrefix)('yellow', ...args)),
  warning: (...args) => console.warn(createMsg('warn', modulePrefix)('yellow', ...args)),
  debug: (...args) => console.log(createMsg('debug', modulePrefix)('blue', ...args)),
  debugAlter: (...args) => {
    if (debugAlternateCounter % 2 === 0) {
      console.log(createMsg('debug', modulePrefix)('cyan', ...args));
    } else {
      console.log(createMsg('debug', modulePrefix)('magenta', ...args));
    }

    debugAlternateCounter += 1;
  },
  time: (...args) => console.time(createMsg('info', modulePrefix)('cyan', ...args)),
  timeEnd: (...args) => console.timeEnd(createMsg('info', modulePrefix)('cyan', ...args)),
  // colors
  cyan: (...args) => console.log(createMsg('info', modulePrefix)('cyan', ...args)),
  magenta: (...args) => console.log(createMsg('info', modulePrefix)('magenta', ...args)),
  blue: (...args) => console.log(createMsg('info', modulePrefix)('blue', ...args)),
  gray: (...args) => console.log(createMsg('info', modulePrefix)('gray', ...args)),
  grey: (...args) => console.log(createMsg('info', modulePrefix)('gray', ...args)),
  white: (...args) => console.log(createMsg('info', modulePrefix)('white', ...args)),
  green: (...args) => console.log(createMsg('', modulePrefix)('green', ...args)),
  yellow: (...args) => console.log(createMsg('', modulePrefix)('yellow', ...args)),
  red: (...args) => console.log(createMsg('', modulePrefix)('red', ...args)),
  hex: (...args) => console.log(createMsg('info', modulePrefix)('hex', ...args)),

  json: (x, { colors = coloredOutput, depth = 4 } = {}) =>
    process.env.NODE_ENV === 'production'
      ? console.log(toJson(x))
      : console.log(util.inspect(x, { colors, depth })),

  jsonDiff: (objA, objB) => {
    const diff = jsondiffpatch.diff(objA, objB);
    const output = jsondiffpatch.formatters.console.format(diff);
    console.log(output);
  },
});
/* eslint-enable no-console */

module.exports = log;