A Go-inspired approach to handling fetch API

Javascript error handling can sometimes be confusing especially in using fetch, if you are using await you will need to wrap it in a try catch block to handle the error and we all know that it's a headache

Well what if i tell you we can do something like this

import { get } from "./eavfetch";

interface Book {
  id: string;
  title: string;
  author: string;
}

async function fetchBooks() {
  // data type is inferred as Book[]
  const [data, error] = await get<Book[]>("/books");

  if (error) {
    console.error("Failed to fetch books:", error);
    return;
  }

  if (data) {
    console.log("Fetched books:", data);
  }
}

Now all of the sudden handling fetch seems easy and very straightforward and safe way to handle error and data right? Well that's the power of error as values approach

you can copy the eavfetch.ts/js in the repo and start using it right away.

Comments

[Fyodor]

There’s nothing bad with try/catch actually — it’s very explicit as opposed to the Go way. Also the native language constructs are always better than hidden abstractions, fwiw. But it all is personal of course.

If you like this specific approach you probably should check out Effect — they do something extremely clever around error handling.

[mmvergara]

Yeah i agree, this approach is going away from js idiomatic way of handling errors.
is this the effect library you are talking about? im quite new on this.

[Fyodor]

Yes, this one. The guys augment the habitual language patterns with some opinionated approaches from other languages and ecosystems.

[Madhan S]

That's a nice method of handling it.

There is a flaw in the code

fetchOptions.headers = {
    "Content-Type": "application/json",
     ...options.headers,
};

The override should come atlast,

fetchOptions.headers = {
     ...options.headers,
    "Content-Type": "application/json",
};

else whatever passed in the options.header will take precedence

[mmvergara]

thanks for the heads up!