Make import.meta.url dynamic

Bug report

What is the current behavior?

import.meta.url is replaced by the current file location at the build time. https://github.com/webpack/webpack/blob/main/lib/dependencies/ImportMetaPlugin.js#L99

If the current behavior is a bug, please provide the steps to reproduce.

If you build

console.log(import.meta.url)

it will ouput a constant string (le location of the file on the current system).

This is problematic to build a project using yargs (https://github.com/yargs/yargs), as it uses meta.import.url (https://github.com/yargs/yargs/blob/main/lib/platform-shims/esm.mjs#L18).

When building under an Unix file system, meta.import.url is replaced by something like file:///path/to/your/project/src/index.js. When trying to run the built code under a Windows filesystem, a TypeError [ERR_INVALID_FILE_URL_PATH]: File URL path must be absolute is thrown, as the filename doesn’t contain file://C:/....

Making the meta.import.url variable dynamic (based on __dirname) should solve the problem.

What is the expected behavior?

import.meta.url should be based on __dirname for cjs build, to keep the original intended behavior of the application developer.

Other relevant information: webpack version: 5.58.1 Node.js version: 16.10.0 Operating System: Ubuntu Linux 20.04 Additional tools: yargs

[Congelli501]

It is the build time location of the file and not the run time dynamic location of the JS file

[pavelsavara]

Hi all, I tried to contribute new configuration option to fix this, but I struggle to make all tests work. I would appreciate some help.

Also I wonder what is the use-case for the current behavior, with the file name from build time. Could somebody advise ? @vankop