string_array_flag.go

package utilities

import (
	"flag"
	"strings"
)

// flagInterface is a cut down interface to `flag`
type flagInterface interface {
	Var(value flag.Value, name string, usage string)
}

// StringArrayFlag defines a flag with the specified name and usage string.
// The return value is the address of a `StringArrayFlags` variable that stores the repeated values of the flag.
func StringArrayFlag(f flagInterface, name string, usage string) *StringArrayFlags {
	value := &StringArrayFlags{}
	f.Var(value, name, usage)
	return value
}

// StringArrayFlags is a wrapper of `[]string` to provider an interface for `flag.Var`
type StringArrayFlags []string

// String returns a string representation of `StringArrayFlags`
func (i *StringArrayFlags) String() string {
	return strings.Join(*i, ",")
}

// Set appends a value to `StringArrayFlags`
func (i *StringArrayFlags) Set(value string) error {
	*i = append(*i, value)
	return nil
}