2022-04-05
1971
#vanilla javascript
Vijit Ail
101953
Apr 5, 2022 â‹… 7 min read

How to write a declarative JavaScript promise wrapper

Vijit Ail Software Engineer at toothsi. I work with React and NodeJS to build customer-centric products. Reach out to me on LinkedIn or Instagram.

Recent posts:

move before api

We can finally move elements in the browser with the moveBefore() API

The newly announced moveBefore() API helps developers easily reposition DOM elements while preserving their state.

Chizaram Ken
Apr 22, 2025 â‹… 8 min read
float ui tutorial

Building responsive websites fast: A Float UI tutorial

Discover Float UI, a set of pre-made templates that leverage the power of Tailwind CSS to help developers create professional websites quickly.

Murat YĂĽksel
Apr 21, 2025 â‹… 22 min read
react toastify

React-Toastify (2025 update): Setup, styling & real-world use cases

Learn how to use React-Toastify in 2025, from setup to styling and advanced use cases like API notifications, async toasts, and React-Toastify 11 updates.

Chimezie Innocent
Apr 18, 2025 â‹… 18 min read
5 Best Open Source Tools For Cross-Browser CSS Testing

5 best open source tools for cross-browser CSS testing

Discover open source tools for cross-browser CSS testing like Playwright and BrowserStack to catch rendering errors, inconsistent styling, and more.

Peter Aideloje
Apr 18, 2025 â‹… 11 min read
View all posts

2 Replies to "How to write a declarative JavaScript promise wrapper"

  1. Another way to handle the try catch if/else is to use the await keyword but use .catch on that promise if you don’t want the outer try catch involved. You can also handle it in the .catch and also re throw it if you would want to halt the execution flow.

    try {
    // business logic includes exception so nds particular handling
    const data = await something()
    .catch(th => {
    // process exception
    // rethrow if some condition
    });
    // only caught by outer bc it’s a zero sum expectation for example
    const more = await someone();
    } catch (th) {
    // handle th
    }

  2. The approach is similar to monad-transformer TaskEither

    https://gcanti.github.io/fp-ts/modules/TaskEither.ts.html

    Actually there is a significant difference between Either.Left and Exception.

    The first one should be used for “recovable” errors, the second one — for unrecoverable.

    So it means we don’t need to avoid throwing an exception in all cases, replacing them with error-result tuple. And the promiser can help with that.

    Nevertheless, the movement to functional programming is great.

Leave a Reply