Regression bug: Relative import of ES6 WASM modules from ES6 Modules does not work

[adevress]

Regression bug introduced by the PR #8940 related to the bug #8729.

Problem :
The PR is based on the fact that 'document.currentScript.src' exists in ES6 modules.
This is not the case for VanillaJS ( no magic bundling ) for Firefox>=68 and Chrome>=76.

This causes any import of ES6 module which is not in the same directory that the source html file to fail.

Reproduce :

Generate a ES6 WASM + js hello_world in a subdirectory
Create a parent main.html page + main.js vanillaJS ES6 module in a parent directory
Import the hello_world from the main.js.
It will fail: The hello_world.js will not succeed to fetch the WASM file.

Temporary Fix :

Override the "locateFile" in the Module itself with a callback that enforce the WASM module path

Definitive Fix:
Enforce the usage of PTHREAD and WebWorker is not a good solution considering that this support is disable in almost all the main WebBrowser for now.

I would be for adding a flag to disable "import.meta.url" on demand. And enable it by default for ANY ES6_MODULE.

[kripken]

cc @VirtualTim

[adevress]

Just added a pull request #9234 with a proposed Fix.

Please do not hesitate to tell me if you do not like the solution.

[VirtualTim]

So if I'm understanding your use case right, your example uses document.currentScript.src, but you want it to use import.meta.url? Before this PR #8306 document.currentScript.src was always used. So this only worked between PR #8306 and PR #8940 (May-July). So while it is a regression it's not that far back.

I guess adding a new flag might be the only solution that keeps everyone happy. I don't really like it, there's already about 200 flags and I was hoping that the toolchain could determine what's best.

This issue is also related to #5104.

[adevress]

Hi Tim,
I was using a version between this two PR yes.
A new flag sounds an appropriate solution to me that can be deprecated in few years when the support for import.meta is universal.

[adevress]

Problem solved. Thanks guys