RFC: v5 Update

[t2t2]

Hi

As noted in obs-websocket 4.9.1 release notes, the next release (5.0) will completely change the protocol. After question flew by in obs discord about 5.0.0 support @tt2468 reached out to @haganbmj if he's still working on this. As his interest in the project has dwindled they decided to transfer the repo to obs-websocket-community-projects and asked @Panger95, @t2t2 and @VodBox to maintain it.

Since the codebase has aged quite a bit and 5.0 will be a major release this gives a good chance to do a larger update.

I'll put the ideas as individual comments in this thread, but major changes will be converting the codebase to typescript, providing an esm/modern build and API changes (some as needed by 5.0 changes, others to clean up code). Please comment on anything you feel strongly about.

[t2t2]

Typescript conversion, packaging and bundling:

• Use microbundle for building/bundling
• Dependencies:
  • events doesn't have the best typings, maybe eventemitter3 (seems to be smaller also)
  • Check others for bundle size differences (sha.js vs crypto-js)

[t2t2]

Tested bundle sizes for sha256 calculations using vite to build following files:

// src/crypto-js.ts
import sha256 from 'crypto-js/sha256'
import Base64 from 'crypto-js/enc-base64'

const test1 = 'asd'
const test2 = 'qwe'

console.log('crypto', Base64.stringify(sha256(test1 + test2)))

// src/sha-js.ts
// @ts-expect-error Could not find a declaration file for module 'sha.js/sha256' (This is with @types/sha.js)
import SHA256 from 'sha.js/sha256'

const test1 = 'asd'
const test2 = 'qwe'

console.log('sha.js', new SHA256().update(test1).update(test2).digest('base64'))

// src/sha-js-full.ts
import SHA from 'sha.js'

const test1 = 'asd'
const test2 = 'qwe'

console.log('sha.js', new SHA.sha256().update(test1).update(test2).digest('base64'))

Also tried hash.js but it didn't have typings and base64 digest support

// vite.config.js
import {resolve} from 'path'

export default {
    build: {
        rollupOptions: {
            input: {
                'crypto-js': resolve(__dirname, 'crypto-js.html'),
                'sha-js': resolve(__dirname, 'sha-js.html'),
                'sha-js-full': resolve(__dirname, 'sha-js-full.html')
            },
            output: {
                manualChunks: false // By default compiles all modules in node_modules across different entrypoints to one vendor.js output file, which we don't want for this test
            }
        }
    }
}

Build:

> tsc && vite build

vite v2.3.7 building for production...
✓ 38 modules transformed.
dist/assets/favicon.17e50649.svg                                  1.49kb
dist/crypto-js.html                                               0.49kb
dist/sha-js.html                                                  0.55kb
dist/sha-js-full.html                                             0.55kb
dist/assets/___vite-browser-external_commonjs-proxy.c0efdbca.js   0.51kb / brotli: 0.25kb
dist/assets/sha-js.5033671a.js                                    0.17kb / brotli: 0.13kb
dist/assets/sha256.21c2fb84.js                                    4.26kb / brotli: 1.64kb
dist/assets/crypto-js.16b1e2ed.js                                 6.02kb / brotli: 2.28kb
dist/assets/sha-js-full.aee2e7cc.js                               7.99kb / brotli: 2.63kb

Since sha-js and sha-js-full both use sha.js/sha256 internally the build system extracted it as a separate artifact, therefore real size for those should add sha256.1fdfd88f.js

Build	crypto-js	sha.js/sha256	sha.js
Size:	6.02kb / brotli: 2.28kb	4.43kb / brotli: 1.77kb	12.25kb / brotli: 4.27kb

However when checking output there was one more issue:

Uncaught TypeError: can't access property "from", o is undefined
    <anonymous> http://localhost:5000/assets/sha256.21c2fb84.js:2
    <anonymous> http://localhost:5000/assets/sha256.21c2fb84.js:2
sha256.21c2fb84.js:2:194

Turns out sha.js uses safe-buffer which requires buffer, which is native in node, webpack automatically polyfills but rollup doesn't, so adding npm install buffer

vite v2.3.7 building for production...
✓ 47 modules transformed.
dist/assets/favicon.17e50649.svg      1.49kb
dist/crypto-js.html                   0.39kb
dist/sha-js.html                      0.45kb
dist/sha-js-full.html                 0.46kb
dist/assets/sha-js.4275ad59.js        0.11kb / brotli: 0.10kb
dist/assets/crypto-js.377ea946.js     6.43kb / brotli: 2.41kb
dist/assets/sha-js-full.d607ba88.js   7.93kb / brotli: 2.60kb
dist/assets/sha256.ae6f968a.js        31.06kb / brotli: 8.59kb

Build	crypto-js	sha.js/sha256	sha.js
Size:	6.43kb / brotli: 2.41kb	31.17kb / brotli: 8.69kb	38.99kb / brotli: 11.19kb

So for best size and typescript support should switch from sha.js to crypto-js

[t2t2]

After posting this I did notice thread about webpack 5 warning about polyfilling crypto module: brix/crypto-js#354

This shouldn't really be an issue since it's fallback for getting secure number generator:

https://github.com/brix/crypto-js/blob/971c31f0c931f913d22a76ed488d9216ac04e306/src/core.js#L38

But since files aren't separated by browser and node usage it is throwing a waning. Option here is to either have instructions in readme about configuring webpack, or PRing a fix, but activity in that repo is also dead.

Looking through npm another option is jsSHA, stats:

// src/jssha.ts
import jsSHA256 from 'jssha/dist/sha256'

const test1 = 'asd'
const test2 = 'qwe'

const obj = new jsSHA256('SHA-256', 'TEXT')
obj.update(test1)
obj.update(test2)

console.log('crypto', obj.getHash('B64'))

vite v2.3.7 building for production...
✓ 15 modules transformed.
dist/assets/favicon.17e50649.svg    1.49kb
dist/jssha.html                     0.39kb
dist/crypto-js.html                 0.39kb
dist/assets/crypto-js.377ea946.js   6.43kb / brotli: 2.41kb
dist/assets/jssha.6c2f99ad.js       9.54kb / brotli: 3.31kb

[duncte123]

• events doesn't have the best typings, maybe eventemitter3 (seems to be smaller also)

I tried to use eventemitter3 but we cannot supply our own types there as that is required for the lib to function properlty

[Panger95]

• events doesn't have the best typings, maybe eventemitter3 (seems to be smaller also)

I tried to use eventemitter3 but we cannot supply our own types there as that is required for the lib to function properlty

I think they fixed this, I may be wrong though

[t2t2]

API Changes: Convert from async connect(args = {}) to async connect(address = 'ws://localhost:4444', password?: string, options?: IdentifyMessageFields)

More of a stylistic choice but would be small size decrease and closer to WebSocket params

[Panger95]

Remove the hardcode of ws://localhost:4444 and instead change to an optional wss://localhost:4444 or ws://localhost:4444

[duncte123]

there is a secure boolean atm that changes ws:// to wss://

[Niek]

I added the secure back then to support both secure and non-secure without breaking changes. But an address override is much better IMHO.

[Panger95]

I think we have to keep the non-override as some systems like @t2t2 use the regular ws protocol I believe

[duncte123]

The solution I came up with will prepend ws:// to the address if no prefix is present 5a91a3d

[t2t2]

API Changes: Remove sendCallback

• Anyone who does want callbacks can use .send(...).then((res) => { ... }, (error) => { ... }) syntax. (which sendCallback does anyway)
• Most modern codebases would async/await promises, making it bloat (and classes can't be treeshaken)

[duncte123]

Removed in this commit 3c6f88d

[Panger95]

Potentially make error logging more intuitive. Currently you will get a lot of uncaught exception errors because by default only errors on the initial socket connection will be caught. Any subsequent errors will need to currently be emitted to a catch all error handler and will be considered uncaught without this handler.

This may require a ton of additional code and I'm not sure how specific we should get with caught errors at the moment.

[t2t2]

obs-websocket 5.0 protocol changes:

From attempting to implement a client, likely new API would be:

• internal? message(messageType: string, data: Object) - to send base messages
• public: reidentify(data: Object) - to send Reidentify message
• rename send to request or call (last matches simpleobsws)?

And the rest from base eventemitter class for event related needs

[t2t2]

Node.js: Follow Node.js LTS EOL schedule and up minimum version to v12

[duncte123]

Completed in the typescript rewrite