Command Execute error not returned to parser. about go-flags

[jessevdk]

You can simply check the error returned from p.Parse(), like this:

package main

import (
    "fmt"
    "github.com/jessevdk/go-flags"
)

type Add struct {
}

func (a *Add) Execute(args []string) error {
    return fmt.Errorf("Some customized error")
}

func main() {
    var opt struct {
    }

    p := flags.NewParser(&opt, flags.Default)

    p.AddCommand("add", "Adding it", "More adding it", &Add{})

    if _, err := p.Parse(); err != nil {
        fmt.Printf("%#v\n", err)
    }
}

If you need to discriminate between your errors and those of the flags package, then you can use if _, ok := err.(flags.Error); !ok ...

Otherwise, you can also simply call os.Exit(1) from your Execute handler, nothing wrong with that. Just print the error yourself (flags just does fmt.Fprintln(os.Stderr, err), but checks for the PrintErrors option).