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K (he/him)
K (he/him)

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Proxymise Your Async Code

If you've written a fair amount of JavaScript these days, it's likely that you came across promises and their language integration async functions. With Proxymise there is now a way to make your code even more consise!

What

Proxymise is a JavaScript library that lets you wrap functions that return promises so you can call methods on the objects they would resolve to.

Why

When using synchronous functions, you can use the returned value directly. This lets you write fluent interfaces for your libraries.

select("*").from("myTable").where("x > 10");
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While async functions helped a bit with some types of invocations, it still can clutter your code.

Proxymise wants to solve this issue.

How

Instead of writing a then chain like this:

fetch("example.com")
.then(r => r.json())
.then(r => r.record.id)
.then(id => ...);
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Or a await list like that:

let r = await fetch("example.com");
r = await r.json();
const {id} = r.record;
...
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It allows you to wrap your promise and call methods on it, making the your interfaces more fluent.

const newFetch = proxymise(fetch);

const {id} = await newFetch("example.com").json().record;
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It does this by returning proxy objects right away while the promise is still in flight. These will then wait for the resolve and apply the function calls later.

Conclusion

Proxymise is a quick way to make asynchronous library usage more consise by getting rid of boilerplate code.

Discussion (9)

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bias profile image
Tobias Nickel

Today I hear the first time about proxy objects, now I find this articel, solving an awefull problem that always disgust me.

Thanks a lot ! !

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kayis profile image
K (he/him) Author • Edited on

Cool :D

I read about proxies rather often, but this is the first application that really blew my mind :D

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kozhevnikov profile image
Ilya Kozhevnikov

Thanks! Btw it's 'proxymise' rather than 'proximise' (portmanteau of 'proxy' and 'promise' that was still available on npm).

Thread Thread
kayis profile image
K (he/him) Author

Oh, good point! :D

Fixed it!

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asparallel profile image
AsParallel

What does the error handling construct look like for proxymise? I know I can read the docs, but that's not very conversational. Im assuming proxymise(op, err) or .catch.

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kayis profile image
K (he/him) Author • Edited on
try {
  const {id} = await newFetch("example.com").json().record;
}
catch(e) {
  console.log(e.message);
}
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nektro profile image
Meghan (she/her)

Wow! What an amazing idea! 👍👍

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d0ruk profile image
Doruk Kutlu

Genius.

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paulchernochshell profile image
PaulChernoch-Shell

This may help us when using loopback to navigate model relationships, which are asynchronous.

  • Paul