Is it possible to disable import.meta transform?

[otakustay]

I'm using vitest to test my NodeJS project which uses import.meta.resolve in ESM mode, now I encounter an error like:

TypeError: __vite_ssr_import_meta__.resolve is not a function

It seems vite transform import.meta into __vite_ssr_import_meta__, which I didn't find a config to disable, however I need NodeJS's built-in imprt.meta.resolve to work.

[sapphi-red]

Vite doesn't support import.meta.resolve yet. For now, I guess you can workaround by replacing import.meta.resolve with import-meta-resolve.

[hi-ogawa]

This might be interesting as a feature request on Vitest (for example, Vitest recently supported import.meta.filename and dirname vitest-dev/vitest#5011).

However, I imagine it would be tricky to support this since I don't think it can just work like "disable import.meta transform". Note that the source code (unless it's externalized) will be executed by vm.runInThisContext (like eval), so genuine import.meta.resolve is not available, which needs to be aware of original source file.

So, Vitest probably requires implementing this based on the 2nd argument version of import.meta.resolve(..., parentURL), but this is only available with --experimental-import-meta-resolve flags, so we would need users to customize poolOptions.execArgv. Also, if it's intended to be used with custom loader, then --import ... also needs to be included in execArgv probably.

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I think it would be helpful if you can provide more details on "I need NodeJS's built-in imprt.meta.resolve to work". For example,

• Is your use case only about Vitest and not Vite SSR?
• Do you use parentURL variant of import.meta.resolve?
• Do you intend to use only relative path (like import.meta.resolve("./some-file.js")) or also node_modules (like import.meta.resolve("some-module"))?
• Do you (or your library's user?) intend to use import.meta.resolve together with NodeJs's custom loaders (e.g. --import tsx/esm)? (polyfill https://github.com/wooorm/import-meta-resolve doesn't work for this use case)

[grabbou]

Hey,

I guess I can chime-in here, as I am running into the same issue right now. My library is using import.meta.resolve to resolve an absolute file URL to a package entry point. Everything works just fine in production, except tests that are not able to run.

The use-case is about Vitest.
I don't use parentURL (right now)
I use it as a direct equivalent of require.resolve after migrating to ES Modules
I intend to use both absolute and package import paths (like require.resolve)
I do not use custom loaders and since this is CLI, I doubt end-users would use that too

[hi-ogawa]

Thanks for explaining the use case. As you might have already seen on my PoC PR vitest-dev/vitest#5188, we are holding back with supporting this at the moment due to the necessity of --experimental-import-meta-resolve.

I use it as a direct equivalent of require.resolve after migrating to ES Modules
I intend to use both absolute and package import paths (like require.resolve)

I see. This sounds like the most natural use case to come at least for Vitest users testing NodeJs app/library.
It might feel like going back to cjs, but I'm wondering using createRequire + require.resolve would be an option for you.
If import.meta.resolve is only used in one place in your code base, then it might be easy to swap out like this:

import { createRequire } from 'node:module'
const require = createRequire(import.meta.url)

// instead of import.meta.resolve
const resolve = require.resolve