Langium + ViteJS

[luiz290788]

Is anyone using langium with vitejs? I'm trying to use and it works fine with the development environment, but when I try to build I am getting this error:

Uncaught TypeError: Object.defineProperty called on non-object
    at Function.defineProperty (<anonymous>)

Any clue on how to solve this?

[msujew]

@kaisalmen Any clue on this? If I remember correctly, you also had trouble using Langium with ViteJS in the context of the langium-website repo.

[kaisalmen]

Yes, when using vite build (=rollup) in lib mode for worker creation. We switched to esbuild with minfy.

[msujew]

I don't think so either. I also don't think it's something that Langium is doing (as at least nothing that's fundamentally wrong), since other bundlers, like esbuild and webpack, and the node runtime itself can deal just fine with it. It's likely just something that Langium is doing that Rollup somehow isn't able to deal with, though I can't think of anything really.

[luiz290788]

Yeah, I agree. I opened a bug for Vite. It could also be related to the specific configuration they apply to rollup.

[luiz290788]

One interesting finding, if try to bundle the langium package in the langium codebase using rollup it works fine. I don't know if the problem is related to the transpiled code.

[luiz290788]

There is a solution, it is to set strictRequires to false in the commonjsOptions. Look at the documentation of strictRequires, it looks like that the problem has to do with the circular dependencies inside of langium. I'm happy to set this to false and continue with my work, as a nice to have, if you could remove the dependencies in future releases, that would help.

[msujew]

Ha, thanks for investigating further, that is really good to know. We'll take some time in the future to remove those cyclic imports, to make it easier to consume Langium in Vite 👍