writeBuffer issue with AllowSharedBufferSource more narrow than before

[johnnybenson]

Hi! Not sure if this is the right place to file an issue.

A change in 0.1.58 makes writeTexture's typing more narrow than before and we are seeing type errors on working code.

SharedArrayBuffer was explicitly included in @types/webgpu in 0.1.56 and removed in 0.1.58.

v0.1.56...v0.1.58

It looks like AllowSharedBufferSource should include SharedArrayBuffer in its type definition looking at this:

AllowSharedBufferSource https://webidl.spec.whatwg.org/#AllowSharedBufferSource

It is not, however, in the Typescript lib.dom type definition. lib/dom.generated.d.ts#L29329

type AllowSharedBufferSource = ArrayBuffer | ArrayBufferView;
type BufferSource = ArrayBufferView | ArrayBuffer;

Not sure where in this tool chain this should be addressed. Is Typescript's type definition wrong? Or if this is an intentional change and SharedArrayBuffer should not be used with textures.

Downgrading @types/webgpu to 0.1.56 for now. Thanks for any insights

[kainino0x]

Hmm. I noticed this in the lib.dom definition of AllowSharedArrayBuffer, and was concerned about it happening. So I tested it:
https://www.typescriptlang.org/play/?#code/PTAEHUAsE9QEwPYFMDOoAukCWaDuCAnAawH4AoAYwQDsV1QAPALlAEEAbdhXAZUgEMCSOACEArgDMJSAjwRiCFJKAC8oaklyg+g4awIF+0cVJkAKACwBKANxkQoAJLoA5GgBGSCvzEplmHFB8YhQAOnDKGjpQaBZ9Q2NJaQJVdU1tASE4eKMTZMtbMiA

And somehow this is fine. I think it's because of structural typing (SharedArrayBuffer has the same interface as ArrayBuffer).

Did you actually hit a compiler error error due to this? (EDIT: Oops, I see that you already said you did.) If so, could you share your compiler settings (tsconfig) so I can reproduce it?

[kainino0x]

(This will presumably need a fix in TypeScript. In order to work on older versions of TypeScript, I'll have to add SharedArrayBuffer back either way - I just want to be able to add a test.)

[johnnybenson]

Here is our tsconfig below. Hopefully it helps to reproduce.

I mis-typed the method, writeTexture appears to be fine and writeBuffer is using the more narrow definition.

Thank you so much for taking a look.

The full error that I see:

Argument of type 'ArrayBufferLike' is not assignable to parameter of type 'AllowSharedBufferSource'.
  Type 'SharedArrayBuffer' is not assignable to type 'AllowSharedBufferSource'.
    Type 'SharedArrayBuffer' is missing the following properties from type 'ArrayBuffer': resizable, resize, detached, transfer, transferToFixedLength

tsconfig.json

{
    "$schema": "https://json.schemastore.org/tsconfig",
    "display": "TSConfig",
    "compilerOptions": {
        "allowJs": false,
        "allowSyntheticDefaultImports": true,
        "alwaysStrict": true,
        "composite": false,
        "esModuleInterop": true,
        "forceConsistentCasingInFileNames": true,
        "incremental": true,
        "inlineSources": false,
        "isolatedModules": true,
        "jsx": "preserve",
        "jsxImportSource": "solid-js",
        "lib": ["dom", "dom.iterable", "esnext"],
        "module": "esnext",
        "moduleResolution": "node",
        "noEmit": true,
        "noEmitOnError": true,
        "noFallthroughCasesInSwitch": true,
        "noImplicitAny": true,
        "noImplicitOverride": true,
        "noImplicitReturns": true,
        "noImplicitThis": true,
        "noUnusedLocals": false,
        "noUnusedParameters": true,
        "preserveWatchOutput": true,
        "resolveJsonModule": true,
        "skipLibCheck": true,
        "strict": true,
        "strictNullChecks": true,
        "target": "esnext",
        "useDefineForClassFields": true,
        "types": ["@webgpu/types", "vite/client", "vitest/globals", "node"]
    },
    "exclude": ["node_modules"]
}

[kainino0x]

Aha, I figured it out. It only comes up with the lib for ES is set to ES2024+. Which I already had set in the tests in this repo, but I hadn't tried putting the test there.

It is indeed due to structural typing that prior versions can't tell SAB can't be cast to AB. In ES2024, AB gained some new properties that SAB doesn't have.

[kainino0x]

Published 0.1.59. Please let me know if it works for you.

Thank you for the report!

[johnnybenson]

amazing, thank you

[kainino0x]

Filed a TypeScript bug: microsoft/TypeScript#61480