README.md

errorist

A JavaScript library that provides traceable errors ✨🕵️

One who encourages and propagates error.

— Wikitionary

TL;DR: check use cases!

Install

The package for errorist is available on the public npm registry.

• With yarn:

yarn add errorist.js

• With npm:

npm install --save errorist.js

Purpose

The library is designed to enforce a better context to an error by:

• Keeping track of an error root causes and detect them at ease;
• Forcing the usage of error codes;
• Encouraging succint, precise error messages;
• Patching errors with related data.

Usage

#1: Custom error class definition

class SomeError extends Errorist {
  constructor(message) {
    super(message || "some human readable message");
    this.code = "some-error-code";
    this.name = "SomeError";
  }
}

// Alternatively:

const SomeError = Errorist.extend({
  message: "some human readable message",
  code: "some-error-code",
  name: "SomeError"
})

#2: Throwing a custom error

try {
  // ...
} catch(e) {
  throw SomeCustomError.create({
    causes: e,
    data: {
      foo: "some data",
      bar: "some other data"
    }
  })
}

#3: Checking for causes

const doSomething = () => {
  throw SomeError.create({
    causes: [new CauseOneError(), new CauseTwoError()]
  });
};

try {
  doSomething();
} catch (e) {
  const err = Errorist.wrap(e); 
  
  err.is(SomeError)             // => SomeError [Errorist]
  err.isCausedBy(SomeError)     // => null
  err.isCausedBy(CauseOneError) // => CauseOneError [Errorist]
  err.is(CauseOneError)         // => CauseOneError [Errorist]
}

#4: Out of the box, Golang style error handling

const [err, thing] = await errorist.try(createThing);
if (err?.is(ThingAlreadyCreatedError)) {
  // ...
}

Maintainers ✨

• Antonio Schönmann (@schonmann)