Expose importer path to dynamicImportFunction

[LarsDenBakker]

Feature Use Case

Native dynamic imports resolve paths relative to the importing module. When implementing a dynamic import polyfill, it would be ideal to implement the same logic.

Feature Proposal

When using dynamicImportFunction, only the imported module path is exposed. It would be great if the importing module URL could be exposed as well.

So instead of:

importShim('./foo.js');

Do:

importShim('./foo', import.meta.url);

A dynamic import polyfill could then resolve the URL somewhat like this:

window.importShim = (id, importer) => {
  const importPath = new URL(id, importer);
  // ... rest of the logic
});

[LarsDenBakker]

See GoogleChromeLabs/dynamic-import-polyfill#8 why this is necessary for polyfills.

[lukastaegert]

I see your point, but I am still undecided. Another approach I am considering is to add a new renderDynamicImport hook that has the ability to both transform the import function and the arguments, and especially add additional ones. Still, your suggestion makes sense as a default when a dynamicImportFunction is supplied.

[lukastaegert]

Here is the renderDynamicImport hook, including an example how to solve your issue: #3449

My preference would be to go with this hook and otherwise deprecate the dynamicImportFunction with the next major version.

[LarsDenBakker]

Deprecating dynamicImportFunction sounds like the right approach here!