Alternative to try-catch wrapping async/await
MIT License
async
and await
are great! SO much better than callbacks all over the place, and helpful for showing that functions are asynchronous, without having to read the function.
What's not so great is having to wrap calls to async
functions in a try-catch.
Maybe this code looks like something in your application:
const id = session.get("id");
let user = undefined;
let products = undefined;
try {
user = await User.find(id);
try {
products = await Product.where("user_id", user.id)
.orderBy("updated_at", "desc")
.limit(50)
.fetch();
} catch (e) {
response.error("Oops! Missing products...");
return;
}
} catch (e) {
response.error("Oops! No user...");
return;
}
response.ok("here are your products...", products);
This is ok, but there are a couple things I don't like about it:
I feel like the gains of being able to avoid promise callbacks are lost by having to wrap everything in a try-catch. I was inspired by some syntax from Go:
user, err := User.find(id)
if err != nil {
log.Fatal(err)
}
// do something with user
So, I implemented something similar, here. Check out how the first example changes, given this new syntax:
const attempt = require("@assertchris/attempt-promise");
const id = session.get("id");
const [err1, user] = await attempt(User.find(id));
if (err1) {
response.error("Oops! No user...");
return;
}
const [err2, products] = await attempt(
Product.where("user_id", user.id)
.orderBy("updated_at", "desc")
.limit(50)
.fetch()
);
if (err2) {
response.error("Oops! Missing products...");
return;
}
response.ok("here are your products...", products);
Use one of these to install:
npm install @assertchris/attempt-promise
yarn add @assertchris/attempt-promise