Exclude file pattern in public from being copied during export

[eliot-akira]

Goals

Allow users to exclude certain files/folders in public from being copied during export

Background

In one project I have a symbolic link in the public directory, which links to a huge folder of files external to the project. I'd like to exclude these files from getting copied during export, so I can just link to the same external folder for the production site.

I tracked down where this copying is happening, in packages/next/src/export/index.ts.

recursiveCopy(publicDir, outDir, {
  filter(path) {
    // Exclude paths used by pages
    return !exportPathMap[path]
   },
})

I tried to use the existing filter exportPathMap as a workaround by creating a dummy page, but couldn't get it to exclude that folder.

Proposal

This could be an option, like excludeExportFromPublicDir, that accepts a string, regular expression pattern, or function that returns boolean. Then in the above code section, the filter option for recursiveCopy can apply this additional user-provided filter.

Alternative solution

In the meantime I was able to solve my use case with a custom server that serves files from a symlinked folder outside of public, under a URL route of the same name. When deploying the exported static site to production, I exclude the folder on the target server where an equivalent symlink exists.