TypeScript eval Projects

quickjs-emscripten

21 1,122 9.4 TypeScript

Safely execute untrusted Javascript in your Javascript, and execute synchronous code that uses async functions

Project mention: New QuickJS Release | news.ycombinator.com | 2023-12-09

Based on your comment below I think you figured out the difference - but if you're looking to execute JS, you can pick between ShadowRealm (where available, or using a polyfill) or my library quickjs-emscripten.
Pros of quickjs-emscripten over ShadowRealm:
- You can use quickjs today in any browser with WASM. ShadowRealm isn't available yet, and polyfills have had security issues in the past. See https://www.figma.com/blog/an-update-on-plugin-security/
- In ShadowRealm eval, untrusted code can consume arbitrary CPU cycles. With QuickJS, you can control the CPU time used during an `eval` using an [interrupt handler] that's called periodically during the eval.
- In ShadowRealm eval, untrusted code can allocate arbitrary amounts of memory. With QuickJS, you can control both the [stack size] and the [heap size] available inside the runtime.
- quickjs-emscripten can do interesting things with custom module loaders and facades that allow synchronous code inside the runtime to call async code on the host.
Pros of ShadowRealm over QuickJS:
- ShadowRealm will (presumably?) execute code using your native runtime, probably v8, JavaScriptCore, or SpiderMonkey. Quickjs is orders of magnitude slower than JIT'd javascript performance of v8 etc. It's also slower than v8/JSC's interpreters, although not by a huge amount. See [benchmarks] from 2019.
- You can easily call and pass values to ShadowRealm imported functions. Talking to quickjs-emscripten guest code requires a lot of fiddly and manual object building.
- Overall the quickjs(-emscripten) API is verbose, and requires manual memory management of references to values inside the quickjs runtime.
[interrupt handler]: https://github.com/justjake/quickjs-emscripten/blob/main/doc...
[stack size]: https://github.com/justjake/quickjs-emscripten/blob/main/doc...
[heap size]: https://github.com/justjake/quickjs-emscripten/blob/main/doc...
[benchmarks]: https://bellard.org/quickjs/bench.html

run

2 26 1.3 TypeScript

Safely execute untrusted code with ESM syntax support, dynamic injection of ESM modules from URL or plain JS code, and granular access control based on whitelisting for each JS object. (by initminal)
SurveyJS

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NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020).