Deno•3d ago

definition for subtle crypto broken?

This code fails when I type-check because

crypto.subtle.digest

crypto.subtle.digest

expects a

BufferSource

BufferSource

as 2nd param, contradicting all the docs and all the examples out there:

async function digest(data: Uint8Array): Promise<string> {
    return Array.from(new Uint8Array(await crypto.subtle.digest('SHA-256', data)))
        .map((b) => b.toString(16).padStart(2, '0'))
        .join('')
}

async function digest(data: Uint8Array): Promise<string> {
    return Array.from(new Uint8Array(await crypto.subtle.digest('SHA-256', data)))
        .map((b) => b.toString(16).padStart(2, '0'))
        .join('')
}

There's nothing wrong with the code and it works just fine, but to pass typechecking I have to cast to

any

any

and silence that, which isn't great

deno 2.5.6 (stable, release, aarch64-apple-darwin)
v8 14.0.365.5-rusty
typescript 5.9.2

deno 2.5.6 (stable, release, aarch64-apple-darwin)
v8 14.0.365.5-rusty
typescript 5.9.2

jcayzacOP•12/12/25, 8:56 AM

…or, well, I can just do too

Doctor 🤖•12/12/25, 6:08 PM

On a side note, there is a toHex() now available on Uint8Array

Doctor 🤖•12/12/25, 7:06 PM

Can you show the exact error you see and what docs you're saying contradict it?

Jjcayzac This code fails when I type-check because `crypto.subtle.digest` expects a `Buff...

ud2•12/12/25, 7:33 PM

Look at the error message.

It tells you that

data

data

is a whose

buffer

buffer

is an , while expects the

buffer

buffer

to be strictly an

ArrayBuffer

ArrayBuffer

. So the fix is to change the type of

data

data

to .

lucsoft•12/12/25, 10:13 PM

data: Uint8Array should be kinda avoided as it doesn't make it clear if its an SharedArrayBuffer or not

lucsoft•12/12/25, 10:13 PM

so if you don't accept an sharedarraybuffer use Uint8Array<ArrayBuffer>

jcayzacOP•12/13/25, 4:23 AM

I think some examples and docs need to get rewritten, then, on both MDN and deno.land.

jcayzacOP•12/13/25, 4:24 AM

Prior to seeing this error I didn't even have any idea was generic, now.

Jjcayzac Prior to seeing this error I didn't even have any idea `Uint8Array` was generic,...

lucsoft•12/13/25, 9:09 AM

Yeah this was a change on typescript

Doctor 🤖•12/13/25, 10:05 AM

5.7