Wasm

[kdy1]

I've managed to implement transformSyncand trasnformFileSync within a wasm module.
Currently, it does not have same api as @swc/core and only two methods are implemented.

Benchmark result

(Note: es2015 = es5 as there's no compiler pass to convert es2015 code to es5 code)

[transform]
  swc (es3) x 391 ops/sec ±2.03% (62 runs sampled)
  swc-wasm (es3) x 94.30 ops/sec ±11.77% (65 runs sampled)
  swc (es2015) x 623 ops/sec ±0.65% (86 runs sampled)
  swc-wasm (es2015) x 151 ops/sec ±0.45% (81 runs sampled)
  swc (es2016) x 1,768 ops/sec ±0.96% (88 runs sampled)
  swc-wasm (es2016) x 526 ops/sec ±0.60% (88 runs sampled)
  swc (es2017) x 1,778 ops/sec ±0.57% (89 runs sampled)
  swc-wasm (es2017) x 535 ops/sec ±0.54% (86 runs sampled)
  swc (es2018) x 2,363 ops/sec ±1.34% (89 runs sampled)
  swc-wasm (es2018) x 745 ops/sec ±0.62% (87 runs sampled)
  swc-optimize (es3) x 543 ops/sec ±0.59% (87 runs sampled)
  babel (es5) x 35.56 ops/sec ±5.80% (53 runs sampled)

It's 3 ~ 4 times slower than the prebuilt binary.

Btw, I'm not sure about the way to implement async apis.

[vovacodes]

Please land this PR, it's such a game-changer!

[kdy1]

@vovaguguiev Can you tell me your usecase? I think x3 slowdown is not a simple issue.

Note: As typical usage of swc involves multiple promises, swc is 60+ times faster than babel.
However, wasm version does not support such threading. So it's only 6x times faster than babel.

[vovacodes]

I would like to use it in a Cloudflare Worker, the options I have there are either JS or WASM. Even 5x speed up comparing to Babel is a great improvement for my use case because of workers’ limits on CPU time per request (50ms)

[vovacodes]

The alternative I am exploring right now is to try and use swc directly from rust code that I compile to wasm, I could write a custom transformation, that I need, directly in Rust similar to how transform-react and other are implemented. Do you think it’s a viable option?

[kdy1]

@vovaguguiev Oh... Fair point.
I forgot environments where native binaries are restricted.
I'll start working on this right now.

[kdy1]

@vovaguguiev I'm pinging you because it's almost done.

I only implemented transformSync, parseSync and printSync at the moment. Is it enough for your use case?

I couldn't make apis related to file because wasm does not support it and I'm not sure if threading is supported in wasm.

[vovacodes]

@kdy1 Thanks a lot! I think sync versions are enough for my case. Look forward to trying it!

[kdy1]

Published @swc/wasm@0.1.0

[whatnickcodes]

@vovacodes did you ever see success with this in a Cloudflare worker? Curious to know what kind of performance you saw / the use case you had?