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yurnalist

Yurnalist

An elegant console reporter, borrowed from Yarn.

Introduction

Pretty console output makes developers happy. Yarn is doing a really nice job. Yurnalist takes the console reporter from Yarn and makes it available for use in other Node.js applications.

Yurnalist can be used to report many different things besides simple messages.

Features

  • log, info, warn, succes, error & command messages
  • progress bars
  • activity spinners
  • process steps
  • object inspection
  • lists
  • emojis
  • trees
  • tables
  • user question
  • user select
  • program header & footer

Install

$ yarn add yurnalist

Or if your prefer NPM

$ npm install yurnalist

How to use

import report from 'yurnalist'
 
/* A function to fake some async task */
function doSomeWork(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}
 
async function fetchSomething() {
  report.info('Wait while I fetch something for you');
  report.warn('It might take a little while though');
 
  const spinner = report.activity();
  spinner.tick('I am on it');
 
  try {
    await doSomeWork(1000);
    spinner.tick('Still busy');
    await doSomeWork(1000);
    spinner.tick('Almost there');
    await doSomeWork(1000);
    report.success('Done!');
  } catch (err) {
    report.error(err);
  }
 
  spinner.end();
}
 
fetchSomething();
 

Requirements

Node >= 4

Examples

Examples showing different API functions are found in /examples. You can run them directly with node >= 7.6 (because of async/await syntax). For older versions you could use the --harmony flag, or otherwise Babel.

To run the activity example:

$ node examples/activity.js

API

Coming soon...

table

step

inspect

list

header

footer

log

success

error

info

command

warn

question

tree

activitySet

activity

select

progress

close

createReporter

Configuration

A normal import gives you a reporter instance configured with defaults for easy use. If you want something else you can call createReporter(options) to give you an instance with different options.

Options

These are the options of the reporter as defined by Flow:

type ReporterOptions = {
  verbose?: boolean,
  stdout?: Stdout,
  stderr?: Stdout,
  stdin?: Stdin,
  emoji?: boolean,
  noProgress?: boolean,
  silent?: boolean,
  peekMemoryCounter?: boolean,
};

The defaults used are:

const defaults = {
  verbose: false,
  stdout: process.stdout,
  stderr: process.stderr,
  stdin: process.stdinn,
  emoji: true,
  noProgress: false,
  silent: false,
  peekMemoryCounter: false,
}

The peekMemoryCounter is disabled by default. If you enable it, you'll have to call reporter.close() to stop its running timer. Otherwise your program will not exit. The memory counter can be used to display in the footer data.

Language

Yarn uses a language file for certain messages. For example if you try to skip a required question, or when you pick an invalid item from a select. This language file is not yet exposed in the Yurnalist API. The only supported language is English, as it is in Yarn at the moment.

I plan to make this configurable so that you can define your own messages in your own language .

Emojis

You can use Emojis in your output. Yurnalist should disable them if they are not allowed in the application environment.

Check:

To Do

Before the 1.0 release there is still some work to be done. You can find an overview in the 1.0 milestone.

If you'd like to help out it is highly appreciated!

Credits

Of course ❤️ and credits to all the contributers of Yarn. The ease with which I was able to extract this module from their codebase is proving some awesome engineering skills.