How to "drain the request stream" about async-busboy

[m4nuC]

What would be the best practice for reading the files e.g. to write them in a data base. I'm currently using fs.readFileSync(files[0].path) and deleting the file with fs.unlink() function.

This should be fine. Although you probably don't need to use fs.unlink(). The OS will do the clean up.

To get the file size one must use fs.stat(PATH) but that's only possible when you have the path already. But how to skip a file upload that exceeds a certain size?

busboy lets you set a fileSize limit. When calling async-busboy you pass as a second argument an option object that will be relayed to busboy:

const {files, fields} = await asyncBusboy(ctx.req, {limits: fileSize: 1000}});