@jfdi/attempt

attempt

The sane way to do error handling in a Functional Programming inspired way

Banish the ungainly, scope-bound try/catch/finally forever!

This is a very simple, lightweight library to implement functional try/catch everywhere. I found myself copying the code into every single project I wrote, so I decided to make it a proper library. It has no dependencies. It's built for both browser and nodeJs use.

Breaking Changes since v1.2.x

Removed attemptAllPromise because it always caused confusion. I might replace it in future with something better.

Installation

npm i @jfdi/attempt

Usage

For synchronous code...

const [error, result] = attempt(fn);
// insert handling code here

For async code...

const [error, result] = await attemptPromise(fn);
// insert handling code here

or for old style promise handling...

attemptPromise(fn).then(([error, result]) => {
    // insert handling code here
});

Examples?

See the tests. They're pretty comprehensive.

Why?

Because I've always hated the ugliness of the try/catch/finally construct ever since I first encountered it in C++.

It's not just an aesthetic thing, although it does make code ugly.

It's mostly this:

let success; // a variable ripe for mutation... can't define this inside any scope below or it'll be unavailable in the others

try {
    // Here's one lexical scope...
    // The code to attempt
    success = true; // mutation
} catch (e) {
    // Here's another lexical scope...
    // The code to handle the error
    success = false; // mutation
} finally {
    // and just because we love all these isolated lexical scopes...
    // Here's the code to run after the whole sorry mess above
    if (success) console.log("Yay!");
}

... and ne'er the three lexical scopes shall meet. Any variable created in the try scope won't be available in the catch scope, and so on, leading to scoping compromises (like declaring variables using let before the try and mutating them in later scopes) and nasty, messy, hard-to-follow code with masses of boilerplate that goes on and on for pages whilst actually doing very little. Yuk. The solution is attempt or attemptPromise. Voila. You're welcome.