### Motivation
Today `didSendRequestPart` is called after a request body part has been passed to the executor. However, this does not mean that the write hit the socket. Users may depend on this behavior to implement back-pressure. For this reason, we should only call this `didSendRequestPart` once the write was successful.
### Modification
Pass a promise to the actual channel write and only call the delegate once that promise succeeds.
### Result
The delegate method `didSendRequestPart` is only called after the write was successful. Fixes#565.
Co-authored-by: Fabian Fett <fabianfett@apple.com>
Swift tools version 5.3 and higher (the version that is specified at very top of a Package.swift file) excludes folders with a dot in the name by default. It luckily produces a warning "found 1 file(s) which are unhandled; explicitly declare them as resources or exclude from the target". However, this issue is buried under a lot of missing types Errors because of the 3 excluded files.
I run into this issue and it took me some time to figure out what the actual problem was. As we will eventually move from 5.2 to 5.3 we can already save the next person some time by resolving this issue now.
Franz BuschandFabian Fett
David Nadoba