Customizing `import.meta` about loaders HOT 2 OPEN

Hey, i'm working on a small library to have some sort of "HMR" with Node ( using the query params hack in the import path ) and I met this need today, so I wanted to share my use case

I need to add two methods in import.meta : import.meta.hot.dipose and import.meta.hot.decline. Because using import.meta.hot.xxx has become a sort a convention since Vite and co.

So to do this, I ended up injecting code via the load hook. But this poses a problem: it totally breaks the source maps. Now, I don't know much about how source maps work, so maybe it's a simple problem to fix ( I will read more about it ), but I thought it was something that could be avoided if Node offered an API to initialize import.meta.

I think, if an API is proposed, it should also be possible to access other properties in import.meta.
In my case, import.meta.hot.decline needs import.meta.url. Here's some silly pseudo code to make my point clearer:

// loader.ts

// Let's say we can do that from a `load` hook
export const load: LoadHook = (url, context, nextLoad) => {
  // maybe using the `context` property? I am not super aware of Nodejs internals
  // so this is probably a dumb idea
  context.initializeImportMeta(importMeta => {
    return {
      hot: {
        dispose: () => {
          // I can access the `import.meta` content through `importMeta`
          myFunction(importMeta.url)
        },
        decline: () => {
          myFunction(importMeta.url)
        }
      }
    }
  })  
}

So having an API for that would allow us to avoid doing code transformations and breaking source maps. Using load for the same result seems a bit hackish anyway

from loaders.

To give a bit more of context, it's already possible to customize import.meta, using globalPreload, but that's going away. Node.js 20.0.0 up to Node.js 20.5.1 are lacking that feature (it was removed "by accident" in the off-thread PR and was re-introduced by nodejs/node#48779), and no one has complained so I think it's fair to say it's not very high priority 🤷‍♂️

But I agree it's worth discussing, and if someone wanted to implement that, it would probably be well received.

from loaders.