From 9335800af101af73f428b79176a42ef0f6153054 Mon Sep 17 00:00:00 2001
From: Stuart Carnie <stuart.carnie@gmail.com>
Date: Thu, 5 Mar 2020 08:21:13 -0700
Subject: [PATCH 1/2] feat(cli): Extend flag support to pflag.Value types

Allows custom types that implement the pflag.Value interface,
which simplifies validation and error handling of flag processing.
---
 kit/cli/viper.go | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/kit/cli/viper.go b/kit/cli/viper.go
index 92110476bf..d12ed8bc68 100644
--- a/kit/cli/viper.go
+++ b/kit/cli/viper.go
@@ -150,6 +150,17 @@ func BindOptions(cmd *cobra.Command, opts []Opt) {
 			}
 			mustBindPFlag(o.Flag, flagset)
 			*destP = viper.GetStringSlice(envVar)
+		case pflag.Value:
+			if hasShort {
+				flagset.VarP(destP, o.Flag, string(o.Short), o.Desc)
+			} else {
+				flagset.Var(destP, o.Flag, o.Desc)
+			}
+			if o.Default != nil {
+				destP.Set(o.Default.(string))
+			}
+			mustBindPFlag(o.Flag, flagset)
+			destP.Set(viper.GetString(envVar))
 		default:
 			// if you get a panic here, sorry about that!
 			// anyway, go ahead and make a PR and add another type.

From ffe63442751c3342865f82802de658d02552a431 Mon Sep 17 00:00:00 2001
From: Stuart Carnie <stuart.carnie@gmail.com>
Date: Thu, 5 Mar 2020 08:30:04 -0700
Subject: [PATCH 2/2] feat(cli): Extend example demonstrating pflag.Value

---
 kit/cli/viper_test.go | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/kit/cli/viper_test.go b/kit/cli/viper_test.go
index ca95a15b46..3fbbd0738e 100644
--- a/kit/cli/viper_test.go
+++ b/kit/cli/viper_test.go
@@ -6,12 +6,36 @@ import (
 	"time"
 )
 
+type customFlag bool
+
+func (c customFlag) String() string {
+	if c == true {
+		return "on"
+	}
+	return "off"
+}
+
+func (c *customFlag) Set(s string) error {
+	if s == "on" {
+		*c = true
+	} else {
+		*c = false
+	}
+
+	return nil
+}
+
+func (c *customFlag) Type() string {
+	return "fancy-bool"
+}
+
 func ExampleNewCommand() {
 	var monitorHost string
 	var number int
 	var sleep bool
 	var duration time.Duration
 	var stringSlice []string
+	var fancyBool customFlag
 	cmd := NewCommand(&Program{
 		Run: func() error {
 			fmt.Println(monitorHost)
@@ -21,6 +45,7 @@ func ExampleNewCommand() {
 			fmt.Println(sleep)
 			fmt.Println(duration)
 			fmt.Println(stringSlice)
+			fmt.Println(fancyBool)
 			return nil
 		},
 		Name: "myprogram",
@@ -55,6 +80,12 @@ func ExampleNewCommand() {
 				Default: []string{"foo", "bar"},
 				Desc:    "things come in lists",
 			},
+			{
+				DestP:   &fancyBool,
+				Flag:    "fancy-bool",
+				Default: "on",
+				Desc:    "things that implement pflag.Value",
+			},
 		},
 	})
 
@@ -68,4 +99,5 @@ func ExampleNewCommand() {
 	// true
 	// 1m0s
 	// [foo bar]
+	// on
 }