cmd/go2go: go2goplay does not have feature parity with play.golang.org

[carnott-snap]

What did you do?

https://go2goplay.golang.org/p/Qho_zVlH3vu

What did you expect to see?

0

What did you see instead?

package name must be main

[andybons]

When initially implementing the go2go playground I remember running into some issues but I’m forgetting what they were.

/cc @ianlancetaylor @griesemer @toothrot

[ianlancetaylor]

I also forget, if I ever know. I guess it is the playground code reporting that error? What happens if you just remove that check?

I've never actually built the playground myself, maybe I'll try it later if I find time.

[thepudds]

Perhaps related, or perhaps not related, but go2goplay.golang.org also does not seem to recognize test cases. It instead reports:

# play
runtime.main_main·f: function main is undeclared in the main package

This does not work:
https://go2goplay.golang.org/p/iw-9AIAjutO

But this does:
https://play.golang.org/p/rtBwSht8Urf

Those are from #39634.

[smasher164]

@andybons Out of curiosity, where does the code for the go2go playground live? I'd like take a stab at adding multifile support.

[andybons]

I should have been more clear: it is known that go2goplay only handles single-file, non-test, main-package cases only for now. None of the additional functionality that the playground has accumulated over the years (multiple files, test cases, modules support, etc.) works. I remember looking into supporting these things but time-boxed myself into just getting the basic use-case up and running. I don’t remember the specific details of what issues I ran into when adjusting the playground code, nor do I know how long the go2go tool will be viable for/how much churn there will be with it.

@smasher164 https://golang.org/cl/238518 has the changes that are currently deployed. We may put that in its own branch since the dev.go2go branch now exists so there’s precedent.

[gopherbot]

Change https://golang.org/cl/240541 mentions this issue: all: go2goplay.golang.org source

[seankhliao]

No longer relevant