A little function that formats an error object as a nice, readable string. Works in node and the browser; in node, it will use kleur to add ANSI color code escape sequences to the output string, to make it easier to read.

• Works in both node and the browser
• Browser version is only ~2k
• Error name and stack are printed in color
• Handles non-error inputs gracefully (accepts unknown in TypeScript)
• Also prints any additional properties that were added to the Error object
  • This is particularly nice when working with node's fs errors; node sometimes puts the information about eg "which file couldn't be read" is sometimes in a property on the error, rather than in the error message, so by printing additional properties, it's guaranteed to be visible.

npm install pretty-print-error

import { formatError } from "pretty-print-error";

const error = new Error("uh oh!");

error.context = {
  user: "jeff",
  session: "ewnj75hvj3v4tvmuy43er",
  favoriteIceCreamFlavor: "pineapple",
};

console.log(formatError(error));
/*
  Logs:

  Error: uh oh!
    at REPL2:1:9
  The above error also had these properties on it:
  {
    context: {
      user: 'jeff',
      session: 'ewnj75hvj3v4tvmuy43er',
      favoriteIceCreamFlavor: 'pineapple'
    }
  }
*/

MIT