> you don't want to be throwing `eval` in your code

Unless you have generated the JS code yourself, in which case it is safe.

What kind of perf are you getting with QuickJS? If you have to evaluate an expression 10,000 times is QuickJS at least half as quick as eval?

True. Though I'd err on the side of caution in case someone in the team makes a PR to enable templating or user data somewhere that uses this code under the hood. Currently working in healthcare, so it's safest to work under the assumption of "don't introduce anything unsafe if possible, even if we know data is sanitized by us". Just in case one day that data is _not_ supplied by us.

RE. perf, I initially used Realms and it was fine. Right now I'm using wasm for templating and cuelang parsing - the speed is _good enough_ for the current UI, though I haven't really done strict performance testing yet, being honest :(

Author here. We have experimented with Realms in the past and had a working version for some time. Also did some POC with quickjs. In both scenarios, we saw performance degrade a lot.. So our current eval is run actually in the web worker so we take extra precautions to avoid leaking any problem some browser api inside the eval context. I like the idea of having a wasm eval environment as well, will experiment with that soon. Thanks for the tips :)

What's the downside of calling eval in the client?