Merge pull request #630 from josephlr/support-custom-flags

Add ability to use custom Flag types

app_test.go

@@ -1520,6 +1520,63 @@ func TestApp_OnUsageError_WithWrongFlagValue_ForSubcommand(t *testing.T) {
 	}
 }
 
+// A custom flag that conforms to the relevant interfaces, but has none of the
+// fields that the other flag types do.
+type customBoolFlag struct {
+	Nombre string
+}
+
+// Don't use the normal FlagStringer
+func (c *customBoolFlag) String() string {
+	return "***" + c.Nombre + "***"
+}
+
+func (c *customBoolFlag) GetName() string {
+	return c.Nombre
+}
+
+func (c *customBoolFlag) Apply(set *flag.FlagSet) {
+	set.String(c.Nombre, c.Nombre, "")
+}
+
+func TestCustomFlagsUnused(t *testing.T) {
+	app := NewApp()
+	app.Flags = []Flag{&customBoolFlag{"custom"}}
+
+	err := app.Run([]string{"foo"})
+	if err != nil {
+		t.Errorf("Run returned unexpected error: %v", err)
+	}
+}
+
+func TestCustomFlagsUsed(t *testing.T) {
+	app := NewApp()
+	app.Flags = []Flag{&customBoolFlag{"custom"}}
+
+	err := app.Run([]string{"foo", "--custom=bar"})
+	if err != nil {
+		t.Errorf("Run returned unexpected error: %v", err)
+	}
+}
+
+func TestCustomHelpVersionFlags(t *testing.T) {
+	app := NewApp()
+
+	// Be sure to reset the global flags
+	defer func(helpFlag Flag, versionFlag Flag) {
+		HelpFlag = helpFlag
+		VersionFlag = versionFlag
+	}(HelpFlag, VersionFlag)
+
+	HelpFlag = &customBoolFlag{"help-custom"}
+	VersionFlag = &customBoolFlag{"version-custom"}
+
+	err := app.Run([]string{"foo", "--help-custom=bar"})
+	if err != nil {
+		t.Errorf("Run returned unexpected error: %v", err)
+	}
+}
+
 func TestHandleAction_WithNonFuncAction(t *testing.T) {
 	app := NewApp()
 	app.Action = 42
@@ -1642,7 +1699,7 @@ func TestShellCompletionForIncompleteFlags(t *testing.T) {
 
 		for _, flag := range ctx.App.Flags {
 			for _, name := range strings.Split(flag.GetName(), ",") {
-				if name == BashCompletionFlag.Name {
+				if name == BashCompletionFlag.GetName() {
 					continue
 				}
 
@@ -1659,7 +1716,7 @@ func TestShellCompletionForIncompleteFlags(t *testing.T) {
 	app.Action = func(ctx *Context) error {
 		return fmt.Errorf("should not get here")
 	}
-	err := app.Run([]string{"", "--test-completion", "--" + BashCompletionFlag.Name})
+	err := app.Run([]string{"", "--test-completion", "--" + BashCompletionFlag.GetName()})
 	if err != nil {
 		t.Errorf("app should not return an error: %s", err)
 	}

flag.go

@@ -14,13 +14,13 @@ import (
 const defaultPlaceholder = "value"
 
 // BashCompletionFlag enables bash-completion for all commands and subcommands
-var BashCompletionFlag = BoolFlag{
+var BashCompletionFlag Flag = BoolFlag{
 	Name:   "generate-bash-completion",
 	Hidden: true,
 }
 
 // VersionFlag prints the version for the application
-var VersionFlag = BoolFlag{
+var VersionFlag Flag = BoolFlag{
 	Name:  "version, v",
 	Usage: "print the version",
 }
@@ -28,7 +28,7 @@ var VersionFlag = BoolFlag{
 // HelpFlag prints the help for all commands and subcommands
 // Set to the zero value (BoolFlag{}) to disable flag -- keeps subcommand
 // unless HideHelp is set to true)
-var HelpFlag = BoolFlag{
+var HelpFlag Flag = BoolFlag{
 	Name:  "help, h",
 	Usage: "show help",
 }
@@ -630,7 +630,8 @@ func (f Float64Flag) ApplyWithError(set *flag.FlagSet) error {
 func visibleFlags(fl []Flag) []Flag {
 	visible := []Flag{}
 	for _, flag := range fl {
-		if !flagValue(flag).FieldByName("Hidden").Bool() {
+		field := flagValue(flag).FieldByName("Hidden")
+		if !field.IsValid() || !field.Bool() {
 			visible = append(visible, flag)
 		}
 	}
@@ -723,9 +724,8 @@ func stringifyFlag(f Flag) string {
 
 	needsPlaceholder := false
 	defaultValueString := ""
-	val := fv.FieldByName("Value")
 
-	if val.IsValid() {
+	if val := fv.FieldByName("Value"); val.IsValid() {
 		needsPlaceholder = true
 		defaultValueString = fmt.Sprintf(" (default: %v)", val.Interface())
 

help.go

@@ -212,8 +212,8 @@ func printHelp(out io.Writer, templ string, data interface{}) {
 
 func checkVersion(c *Context) bool {
 	found := false
-	if VersionFlag.Name != "" {
-		eachName(VersionFlag.Name, func(name string) {
+	if VersionFlag.GetName() != "" {
+		eachName(VersionFlag.GetName(), func(name string) {
 			if c.GlobalBool(name) || c.Bool(name) {
 				found = true
 			}
@@ -224,8 +224,8 @@ func checkVersion(c *Context) bool {
 
 func checkHelp(c *Context) bool {
 	found := false
-	if HelpFlag.Name != "" {
-		eachName(HelpFlag.Name, func(name string) {
+	if HelpFlag.GetName() != "" {
+		eachName(HelpFlag.GetName(), func(name string) {
 			if c.GlobalBool(name) || c.Bool(name) {
 				found = true
 			}
@@ -260,7 +260,7 @@ func checkShellCompleteFlag(a *App, arguments []string) (bool, []string) {
 	pos := len(arguments) - 1
 	lastArg := arguments[pos]
 
-	if lastArg != "--"+BashCompletionFlag.Name {
+	if lastArg != "--"+BashCompletionFlag.GetName() {
 		return false, arguments
 	}