Webpack5: how to get module parents/dependants (or deps graph) from loader

[wclr]

In one of my loaders, I need to know parents/dependants that the current module (handled by loader) was requested by. For this in webpack4 I used a hacky way to do this with access to this._module.reasons, but in webpack 5 reasons prop does not exist on _module object (which is a too deprecated prop). So how the actual task of getting requested parents from within loader may be accomplished in Webpack 5?

[alexander-akait]

I think you need to rewrite the loader to the plugin, it is not safe using this._module.reasons in the loader in webpack@4, the loader should not do this stuff, please provide link on loader or more information if you need help, I close issue because it was invalid usage, do not rely on private behavior, anyway if you will provide more information I will help you here

[wclr]

This is the code of loader https://github.com/whitecolor/lp-loader/blob/master/src/lp-loader.ts it produces language bundles by combining language for files from different dicts based on where those dicts are required.

Didn't write the plugins, so advice would be appreciated.

[alexander-akait]

You really need plugin for this case, using loader is bad idea, just use hook, I think you can use this hook https://github.com/webpack/webpack/blob/master/lib/Compilation.js#L406

[wclr]

@evilebottnawi
Hope you don't mind me asking some questions here. This is not an easy thing to get the right way (API) for doing things in webpack internals.

You proposed to use afterOptimizeTree hook, where I believe I should add new modules and chunks which currently my loader creates using require.ensure API.

A couple of questions:

1. How to add/load new modules from known filePath in this hook? (could not find API for creating/loading new module instances.)
2. How to change the code of an already loaded module?