Asserting on download links

[mattwynne]

Hey German,

We're writing a test for a link that downloads a file. Here's what we ended up with:

It would be ideal if we could do something more like:

   visit(~"/jobs/dajob/packets/#{packet}")
|> click_link("Download")
|> assert_downloaded(:json, Jason.encode!(packet), filename: "my-packet.json")

What do you reckon? I realize it's switching paradigm from live view to more traditional controller request/response. We tried using unwrap but weren't sure how to do it with the view that you get from that.

I'd be happy to spend some time trying to factor an assert_downlaoded out of our code if you think it would be useful and have some tips about what it would look like.

[germsvel]

Hey @mattwynne. So good to hear from you!

You're not the first to think of having an assert_download would be good. I'm intrigued by your solution because I've been wondering for a while how we handle the LiveView side (since really, downloads are a "traditional controller request/response", like you said).

The previous work is in #111. I wonder what you think of that API, or if you'd make some changes so that it works for the LiveView version you're thinking of.

I'd certainly be happy to have an assert_download or assert_downloaded function. I just haven't had time to think about how to make it work nicely across LiveViews and dead views.

[mattwynne]

dead view

🤣

We used a "dead view" (traditional controller endpoint) for the download so, from what I can tell, the proposal in #111 would work perfectly for our use-case.

I'm not even sure how you would implement file downloads from a LiveView.

So I'd give a 👍🏻 to #111.

[ftes]

I'm not even sure how you would implement file downloads from a LiveView.

The patterns I know for downloading files from LiveViews

1. Link from LiveView to Deadview (can verify in phoenix_test)
2. Trigger file download via Javascript (javascript hooks or simlar - can't verify in phoenix_test)