dearchap

Fixed in release v2.19.2

Issue not present in latest releases. Closing.

I dont think this is a trivial fix. Consider the following code with urfave:main(without this PR fix) ``` package main import ( "fmt" "os" "github.com/urfave/cli/v2" ) func printer(s, action string)...

PR #1553 Does this on latest and uses the internal gen flag program.

So the flag validator can be performed via the Flag Action handler. I've added an example in the documentation. That should suffice for most use cases. For v3 we can...

This approach has been considered but dropped due to favoring a different mechanism using a validation API. That would allow ALL flags to use validation code instead of creating a...

@meatballhat Yes that would be fine. However it might be worthwhile to add a light interface with implementation left to users for extending. And most common use cases can be...

Will open a new PR with a small validation API

@FGYFFFF @meatballhat I fixed the code to ignore empty category and also fixed the tests for this.

@meatballhat Can you take a look at test-docs ?