human-error

Allows you to write errors so people can understand:

An error while running node app.js	Same error while testing with jest

Getting started

Install it with NPM:

npm install human-error

Then create your error codes:

// myfun-errors.js
const errors = require('human-error')({
  // [optional] a url where the error is explained in-depth
  url: name => `http://example.com/error/${name}`
});
 
// "NAMESPACE" can be whatever you want (or nothing at all)
errors['NAMESPACE.missingcallback'] = () => `
  myFun() expects a callback to be passed but nothing was passed.
`;
 
errors['NAMESPACE.invalidcallback'] = ({ type }) => `
  myFun() expects the argument to be a callback function.
  ${type ? `"${type}" was passed instead.` : ''}
`;
 
module.exports = errors;

Then use them in your code:

// myfun.js
const errors = require('./myfun-errors');
 
module.exports = (cb) => {
  if (!cb) {
    throw errors('NAMESPACE.missingcallback');
  }
  if (!(cb instanceof Function)) {
    throw errors('NAMESPACE.invalidcallback', { type: typeof cb });
  }
  cb('Cool library!');
};

Options

• url [false]: if there's an url to show more info. It can be a string in which case it will just be printed or a function that build the error such as (key) => 'https://example.com/errors#' + key so you can show the appropriate support url.
• extra [{}]: an object that defaults to all of the options in the namespace. Useful for example for status code errors (status: 500) etc.
• width [80]: the minimum width of the row. It cannot cut strings since links shouldn't be cut.
• plain [false]: avoid generating a table and using plain-text only, in case some things break.