Remove logging the origin line in Jest

Question

Jest has this feature to log the line that outputs to console methods.

In some cases, this can become annoying:

  console.log _modules/l         


        

Answer 1

Update: For newer versions of Jest, see Harald Wellmann's answer.

---

Looking at the source code for Jest, it doesn't seem like there is a neat way to turn those messages off.

However, one possible solution could be to write your own Console. Here I have used Console.js from Jest as a starting ground, and then created SimpleConsole which does what you need (I have removed some terminal coloring features for simplicity, but you could just add them yourself).

Once added to your project, you can overwrite Jest's normal console with your own before running the tests:

const { SimpleConsole } = require('./SimpleConsole');
global.console = new SimpleConsole(process.stdout, process.stderr);

I have made a REPL that shows it in action.

The source code for SimpleConsole:

const path = require('path');
const assert = require('assert');
const {format} = require('util');
const {Console} = require('console');

function simpleFormatter() {
  const TITLE_INDENT = '    ';
  const CONSOLE_INDENT = TITLE_INDENT + '  ';

  return (type, message) => {
    message = message
      .split(/\n/)
      .map(line => CONSOLE_INDENT + line)
      .join('\n');

    return (
      message +
      '\n'
    );
  };
};

class SimpleConsole extends Console {
  constructor(stdout, stderr, formatBuffer) {
    super(stdout, stderr);
    this._formatBuffer = formatBuffer || simpleFormatter();
    this._counters = {};
    this._timers = {};
    this._groupDepth = 0;
  }

  _logToParentConsole(message) {
    super.log(message);
  }

  _log(type, message) {
    if (process.stdout.isTTY) {
      this._stdout.write('\x1b[999D\x1b[K');
    }
    this._logToParentConsole(
      this._formatBuffer(type, '  '.repeat(this._groupDepth) + message),
    );
  }

  assert(...args) {
    try {
      assert(...args);
    } catch (error) {
      this._log('assert', error.toString());
    }
  }

  count(label = 'default') {
    if (!this._counters[label]) {
      this._counters[label] = 0;
    }

    this._log('count', format(`${label}: ${++this._counters[label]}`));
  }

  countReset(label = 'default') {
    this._counters[label] = 0;
  }

  debug(...args) {
    this._log('debug', format(...args));
  }

  dir(...args) {
    this._log('dir', format(...args));
  }

  dirxml(...args) {
    this._log('dirxml', format(...args));
  }

  error(...args) {
    this._log('error', format(...args));
  }

  group(...args) {
    this._groupDepth++;

    if (args.length > 0) {
      this._log('group', chalk.bold(format(...args)));
    }
  }

  groupCollapsed(...args) {
    this._groupDepth++;

    if (args.length > 0) {
      this._log('groupCollapsed', chalk.bold(format(...args)));
    }
  }

  groupEnd() {
    if (this._groupDepth > 0) {
      this._groupDepth--;
    }
  }

  info(...args) {
    this._log('info', format(...args));
  }

  log(...args) {
    this._log('log', format(...args));
  }

  time(label = 'default') {
    if (this._timers[label]) {
      return;
    }

    this._timers[label] = new Date();
  }

  timeEnd(label = 'default') {
    const startTime = this._timers[label];

    if (startTime) {
      const endTime = new Date();
      const time = endTime - startTime;
      this._log('time', format(`${label}: ${time}ms`));
      delete this._timers[label];
    }
  }

  warn(...args) {
    this._log('warn', format(...args));
  }

  getBuffer() {
    return null;
  }
}

module.exports.SimpleConsole = SimpleConsole;