basicflag provider support skips already set items

[beihai0xff]

basicflag provider will skips over any flag values that have default values set, saving unnecessary processing for already set items.
Tests are modified to include the basicflag module.

[knadh]

Hi @beihai0xff. This breaks backwards compatibility with changes to Provider() and ProviderWithValue().

[beihai0xff]

Hi @beihai0xff. This breaks backwards compatibility with changes to Provider() and ProviderWithValue().

Can I add some new functions to see if the flags defined have been set from other providers? Like the code below:

func ProviderKo(f *flag.FlagSet, delim string, ko KoanfIntf) *Pflag {}
func ProviderKoWithValue(f *flag.FlagSet, delim string, ko KoanfIntf, cb CallBack) *Pflag {}

[knadh]

Thinking about this, perhaps it's better to not integrate these changes into the core as they are opinionated? It's all easily pluggable anyway.

[beihai0xff]

Thinking about this, perhaps it's better to not integrate these changes into the core as they are opinionated? It's all easily pluggable anyway.

I add an option argument opts as type Option func(*Pflag) that modifies the Pflag. If you do not want to auto merge the flags defined have been set from other providers, no opts argument will be passed, but if you want to enable auto merge, should add basicflag.WithEnableMerge
Now You can call Provider() like below:

basicflag.Provider(bf, ".")
basicflag.Provider(fs, ".", basicflag.WithEnableMerge(k))
basicflag.Provider(fs, ".", basicflag.WithEnableMerge(k),
		basicflag.WithCallBack(func(key string, value flag.Value) (string, any) {
			return key, value.(flag.Getter).Get()
		}))

Take the long view, we can add more option function for extensibility

[knadh]

Thanks, but I think it's best not to change the current implementation for now. If there are more requests for customizing basicflag's behaviour in the future, this can be considered. For now, you can continue to maintain your version of the provider in case anyone else also wants to use it. All providers are pluggable in koanf precisely so that it's easy to maintain different opinionated providers that can be plugged easily.

Thanks again.