Why is `crypto.subtle.digest` async?

Ethan@programming.dev to Programming@programming.dev – 15 points –

Why is crypto.subtle.digest designed to return a promise?

Every other system I've ever worked with has the signature hash(bytes) => bytes, yet whatever committee designed the Subtle Crypto API decided that the browser version should return a promise. Why? I've looked around but I've never found any discussion on the motivation behind that.

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It’s standard for operations that take a while and can be performed asynchronously.

What’s your problem with it?

async/await infecting all of my code, being unable to create a get myField() method that involves a hash calculation. It may be standard to do heavy lifting concurrently, but async hash functions are certainly not standard in any of the languages I've used (which is quite a few).

From browsing your other comments on this thread I understand that you are in a context where you can’t await, that you expect the invocation to take very little time, and that the library offers no complementary sync interface.

As far was I know you’re stuck in this case. I consider the stubborn refusal to add “resolve this promise synchronously right now” a major flaw in js.

Given the nature of JS running only on a single thread. Promises/asynchronity is the only way to keep the browser from locking up.

Thus insisting on any other way is a major flaw in the developer not the language.

Thus insisting on any other way is a major flaw in the developer not the language.

I mean, I understand the idea, but this is a pretty asshole way to frame it. I don’t think I deserve that, and certainly OP doesn’t deserve that.

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