Add count option for bool flags

[dearchap]

What type of PR is this?

• feature

What this PR does / why we need it:

This PR add a way of counting number of times a bool flag is set. This is useful when specifying the flag multiple times(-v -v -v etc).

Which issue(s) this PR fixes:

#757

Special notes for your reviewer:

Testing

Add test code in flag_test.go

go test -run=TestBoolFlagApply_SetsCount ./...

Release Notes

Adds ability to count number of occurrences of bool flags

[alexcb]

I was looking for this functionality and was considering implementing it, but it looks like it's already been done 🎉

Is there any chance of getting this merged?

I'm happy to help if there's anything else that needs to be done and @dearchap is short on time.

[coilysiren]

I was just thinking about this feature the other day! Yay for a PR! I'll try to review it soon 🙏🏼

[dearchap]

I was just thinking about this feature the other day! Yay for a PR! I'll try to review it soon 🙏🏼

Can you review it soon @coilysiren . Its been more than a month since you suggested it. The code is pretty straightforward and also includes tests so the risk is very low.

[dearchap]

Ping @coilysiren

[meatballhat]

@dearchap sorry for the conflicts!

[dearchap]

@meatballhat Merged my changes. There seems to be a circular dependency. The go generate wont run if it cant build the current code and the current code wont work unless the new spec has been generated.

[meatballhat]

@dearchap You're absolutely right about the circular dependency 😭 I was hoping that we could "dogfood" the local version of urfave/cli in ./internal/genflags/cmd/ but maybe that's going to be more painful than is reasonable. I'd like to try out a nested go.mod approach with the version pinned to last release rather than removing urfave/cli usage entirely 🤔

[icholy]

I'm late to the party, but I would have expected the count to be exposed via a context method.

func main() {
	app := &cli.App{
		Flags: []cli.Flag{
			&cli.BoolFlag{
				Name:  "foo",
				Usage: "foo greeting",
			},
		},
		Action: func(cCtx *cli.Context) error {
			fmt.Println("count", cCtx.Count("foo"))
			return nil
		},
	}
	if err := app.Run(os.Args); err != nil {
		log.Fatal(err)
	}
}

[dearchap]

@meatballhat Added an example in docs but for some reason it is taking the "args" tag to execute the app

[dearchap]

@icholy I think you are correct. It would be good to have a ctx.Count("flagName"). That introduces some additional complexity as we would probably want to have a CountableFlag interface etc etc. Let me see what I can do

[dearchap]

@icholy @meatballhat what do you think ?