Adds a setting that allows opp to keep your master branch clean.

[cupcicm]

When opp.keep_master_clean is set, if you create a PR, the commits
you have selected in the PR will be removed from the master branch.
This keeps the master branch clean.

[cupcicm]

@gabrielreid it was good to meet you in Paris ! It made me think about you and I tried to implement this over the weekend, which is the feature I think you wanted from opp. I haven't had time to test this extensively, but I think it works.

What's pretty cool (IMO) is that it works even with opp pr -i meaning if I have 4 commits, run opp pr -i, select the 1st one and the 3rd one in my PR, then my master branch will then contain only commit 2 and 4 (if applying 2 then 4 doesn't conflict).

WDYT ? Can you test it and tell me if it works ? Need to set a hidden config parameter in .opp/config.yaml

[gabrielreid]

Oh wow, awesome!

I'll give it a try and let you know 👍

[cupcicm]

Thanks I'll do the same. I think it's working in many of the usual cases, but seeing how many git rebase --onto it's taken to make it work, being careful is a good thing I think.

[gabrielreid]

I've mostly just been testing this, and it seems to definitely work for my general flow that I always use, so this definitely seems good to me 👍

This did make me try opp pr -i, which I otherwise never use, and I discovered that it seems to fail for me (regardless of this PR) with the following

Choose what commits you want to include in this PR
panic: tried to abort the rebase but failed: exit status 128

goroutine 1 [running]:
github.com/cupcicm/opp/core.(*Repo).TryRebaseOntoSilently(0x1?, {0x10108b590, 0x1400018ee10}, {0x64, 0xba, 0xea, 0xf2, 0x64, 0x9c, 0xbb, ...}, ...)
	/Users/greid/development/opp/core/repo.go:242 +0x270
github.com/cupcicm/opp/cmd.(*create).RebasePrCommits(0x1400022b8d0, {0x10108b590, 0x1400018ee10}, 0x140003c6060)
	/Users/greid/development/opp/cmd/pr.go:216 +0x130
github.com/cupcicm/opp/cmd.PrCommand.func1(0x14000036280)
	/Users/greid/development/opp/cmd/pr.go:88 +0xbc
github.com/urfave/cli/v2.(*Command).Run(0x14000294420, 0x14000036280, {0x14000080340, 0x2, 0x2})
	/Users/greid/go/pkg/mod/github.com/urfave/cli/v2@v2.25.7/command.go:274 +0x730
github.com/urfave/cli/v2.(*Command).Run(0x14000092160, 0x140000361c0, {0x1400019e120, 0x3, 0x3})
	/Users/greid/go/pkg/mod/github.com/urfave/cli/v2@v2.25.7/command.go:267 +0x940
github.com/urfave/cli/v2.(*App).RunContext(0x14000296000, {0x10108b590?, 0x1400018ee10}, {0x1400019e120, 0x3, 0x3})
	/Users/greid/go/pkg/mod/github.com/urfave/cli/v2@v2.25.7/app.go:332 +0x518
main.main()
	/Users/greid/development/opp/opp.go:54 +0x2f8

Anyhow, that error happens even when running on main though, so no reason to not merge this PR because of it.

[gabrielreid]

I'll admit I don't fully get the logic here, but this looks to me like there should be a return err or something similar here (or if it's intentional that we keep going on this point, that a comment explaining why would help).

That's mostly my lack of understanding of fancy git rebasing tricks speaking here though 😬

[cupcicm]

Yeah you're right, when the rebase fail we shouldn't continue as if nothing happened.

[cupcicm]

I discovered that it seems to fail for me
Weird 🤔 this doesn't happen to me.
Is it doable to create a chain of commit and show me what gets you in this situation by any chance ? The error means:

1. opp tried to create a PR that contains just the commits you selected in the rebase todo file but couldn't (e.g. the commits you selected didn't apply cleanly on master)
2. When this happens opp run git rebase --abort to get you back to a state that's clean but this rebase failed too. Usually when 1. happens the rebase aborts correctly and you don't get the error.

[gabrielreid]

About my opp pr -i issue, I've confirmed that it happens regardless of this feature.

I can reproduce it by checking out a clean version of main of this repo: https://github.com/gabrielreid/testing, configuring opp (i.e. running opp init), and then doing the following:

$ echo something >> test.txt
$ git add test.txt && git commit -m 'test 1'
$ opp pr -i

That reliably gives me this output:

Choose what commits you want to include in this PR
panic: tried to abort the rebase but failed: exit status 128

goroutine 1 [running]:
github.com/cupcicm/opp/core.(*Repo).TryRebaseOntoSilently(0x1?, {0x1057036b0, 0x1400007ce10}, {0x8d, 0xf2, 0x90, 0xb0, 0x12, 0x5d, 0xb3, ...}, ...)
	/Users/greid/development/opp/core/repo.go:242 +0x270
github.com/cupcicm/opp/cmd.(*create).RebasePrCommits(0x1400017b8b0, {0x1057036b0, 0x1400007ce10}, 0x140001d7a40)
	/Users/greid/development/opp/cmd/pr.go:241 +0x130
github.com/cupcicm/opp/cmd.PrCommand.func1(0x140001d6700)
	/Users/greid/development/opp/cmd/pr.go:88 +0xc4
github.com/urfave/cli/v2.(*Command).Run(0x140001e2420, 0x140001d6700, {0x140001da420, 0x2, 0x2})
	/Users/greid/go/pkg/mod/github.com/urfave/cli/v2@v2.25.7/command.go:274 +0x730
github.com/urfave/cli/v2.(*Command).Run(0x140001e2dc0, 0x140001d6640, {0x14000020150, 0x3, 0x3})
	/Users/greid/go/pkg/mod/github.com/urfave/cli/v2@v2.25.7/command.go:267 +0x940
github.com/urfave/cli/v2.(*App).RunContext(0x140001e4000, {0x1057036b0?, 0x1400007ce10}, {0x14000020150, 0x3, 0x3})
	/Users/greid/go/pkg/mod/github.com/urfave/cli/v2@v2.25.7/app.go:332 +0x518
main.main()
	/Users/greid/development/opp/opp.go:54 +0x2f8

I don't know of anything "special" on my machine, and the output of git version is git version 2.39.3 (Apple Git-145) (if that's worth anything).

[cupcicm]

OK @gabrielreid Sorry I didn't have time to look into it before today. So this is due to the fact this branch of the code doesn't check that you have a local diff. If you do, when it's trying to do the rebase magic your local diff gets in the way and 💥 .
We'll add a check that tells you to stash if you have this setting.