[robsimmons]

Project cogwheel grows a new header — intentionally a MenuItem with a href and not a Next-ified MenuLinkItem, since we definitely don't want prefetching — which downloads a tarball without ever materializing it on the hard drive.

Learned a couple fun things in the process:

• The Content-Disposition header header, which is how you tell a route that it's a file that should be downloaded.
• Streaming responses in Next.js route handlers, which are perfect for this use case.

[Vtec234]

One potential surprise here is that this gets the project dir which wouldn't contain all the overlaid files (.lake/packages from package sets). That's probably better, though, since it reduces the tgz size.

[robsimmons]

@Vtec234 I'm actually explicitly excluding .lake in its entirety. If we have overlay files in the future that aren't part of .lake I'd think those should be part of the download.

[jcreedcmu]

Yeah, I think I would also cast a vote for excluding .lake for now until and unless we hear a user wanting different behavior (and having, like, a user-facing checkbox for include/exclude build files is a possible choice)

The value of including .lake is in the form of a convenience, i.e. making the transition from web to desktop a seamless "just works". But the tarball being small is also convenient.

[jcreedcmu]

thought that needn't be for this PR but I'm noticing a repeated pattern: should we extract a helper function that makes "check if this project seems to exist according to our current auth'ed user" easier to naturally get right?

[robsimmons]

Took a crack at this for #204