[Webpack 5] Incorrect mappings with copy-webpack-plugin

[alex996]

• Manifest Plugin Version: ^3.0.0-rc.0
• Webpack Version: ^5.6.0 (latest to date)
• Operating System (or Browser): Ubuntu 20.04 / Chrome 86
• Node Version: v14.13.1
• Link to reproduction (⚠️ read below): https://github.com/alex996/webpack-manifest-demo/tree/copy-webpack-plugin

Use Case

Copying static asset files (e.g. images) using copy-webpack-plugin. Not sure if this use case is supported (i.e. whether it's a bug report or a feature request), but this package does produce the mappings that are sadly incorrect.

Expected Behavior

The key in manifest.json should match the original file name (and path), and not include the resulting contenthash. For example, given an image myimage.99217f7d9cb04497c0c92f3c0d0f82f1.png the key should be myimage.png.

Actual Behavior

The key is incorrect in that it also includes the contenthash making the mapping unusable and impractical.

Additional Information

Please see the full details in the readme of the repo.

[shellscape]

Same issue as #210, #208, and #167. (Please do remember to search before opening new issues)