Rename func type suffixes `Fn`->`Func` and add `OnUsageErrorFunc`

altsrc/flag.go

@@ -38,7 +38,7 @@ func ApplyInputSourceValues(context *cli.Context, inputSourceContext InputSource
 // InitInputSource is used to to setup an InputSourceContext on a cli.Command Before method. It will create a new
 // input source based on the func provided. If there is no error it will then apply the new input source to any flags
 // that are supported by the input source
-func InitInputSource(flags []cli.Flag, createInputSource func() (InputSourceContext, error)) cli.BeforeFn {
+func InitInputSource(flags []cli.Flag, createInputSource func() (InputSourceContext, error)) cli.BeforeFunc {
 	return func(context *cli.Context) (int, error) {
 		inputSource, err := createInputSource()
 		if err != nil {
@@ -52,7 +52,7 @@ func InitInputSource(flags []cli.Flag, createInputSource func() (InputSourceCont
 // InitInputSourceWithContext is used to to setup an InputSourceContext on a cli.Command Before method. It will create a new
 // input source based on the func provided with potentially using existing cli.Context values to initialize itself. If there is
 // no error it will then apply the new input source to any flags that are supported by the input source
-func InitInputSourceWithContext(flags []cli.Flag, createInputSource func(context *cli.Context) (InputSourceContext, error)) cli.BeforeFn {
+func InitInputSourceWithContext(flags []cli.Flag, createInputSource func(context *cli.Context) (InputSourceContext, error)) cli.BeforeFunc {
 	return func(context *cli.Context) (int, error) {
 		inputSource, err := createInputSource(context)
 		if err != nil {

app.go

@@ -47,21 +47,19 @@ type App struct {
 	// Populate on app startup, only gettable throught method Categories()
 	categories CommandCategories
 	// An action to execute when the bash-completion flag is set
-	BashComplete BashCompleteFn
+	BashComplete BashCompleteFunc
 	// An action to execute before any subcommands are run, but after the context is ready
 	// If a non-nil error is returned, no subcommands are run
-	Before BeforeFn
+	Before BeforeFunc
 	// An action to execute after any subcommands are run, but after the subcommand has finished
 	// It is run even if Action() panics
-	After AfterFn
+	After AfterFunc
 	// The action to execute when no subcommands are specified
-	Action ActionFn
+	Action ActionFunc
 	// Execute this function if the proper command cannot be found
-	CommandNotFound CommandNotFoundFn
-	// Execute this function, if an usage error occurs. This is useful for displaying customized usage error messages.
-	// This function is able to replace the original error messages.
-	// If this function is not set, the "Incorrect usage" is displayed and the execution is interrupted.
-	OnUsageError func(context *Context, err error, isSubcommand bool) error
+	CommandNotFound CommandNotFoundFunc
+	// Execute this function if an usage error occurs
+	OnUsageError OnUsageErrorFunc
 	// Compilation date
 	Compiled time.Time
 	// List of all authors who contributed

command.go

@@ -26,19 +26,17 @@ type Command struct {
 	// The category the command is part of
 	Category string
 	// The function to call when checking for bash command completions
-	BashComplete BashCompleteFn
+	BashComplete BashCompleteFunc
 	// An action to execute before any sub-subcommands are run, but after the context is ready
 	// If a non-nil error is returned, no sub-subcommands are run
-	Before BeforeFn
+	Before BeforeFunc
 	// An action to execute after any subcommands are run, but after the subcommand has finished
 	// It is run even if Action() panics
-	After AfterFn
+	After AfterFunc
 	// The function to call when this command is invoked
-	Action ActionFn
-	// Execute this function, if an usage error occurs. This is useful for displaying customized usage error messages.
-	// This function is able to replace the original error messages.
-	// If this function is not set, the "Incorrect usage" is displayed and the execution is interrupted.
-	OnUsageError func(context *Context, err error) error
+	Action ActionFunc
+	// Execute this function if a usage error occurs.
+	OnUsageError OnUsageErrorFunc
 	// List of child commands
 	Subcommands Commands
 	// List of flags to parse
@@ -125,7 +123,7 @@ func (c Command) Run(ctx *Context) (ec int, err error) {
 
 	if err != nil {
 		if c.OnUsageError != nil {
-			err := c.OnUsageError(ctx, err)
+			err := c.OnUsageError(ctx, err, false)
 			if err != nil {
 				return DefaultErrorExitCode, err
 			}

command_test.go

@@ -81,7 +81,7 @@ func TestCommand_OnUsageError_WithWrongFlagValue(t *testing.T) {
 			Flags: []Flag{
 				IntFlag{Name: "flag"},
 			},
-			OnUsageError: func(c *Context, err error) error {
+			OnUsageError: func(c *Context, err error, _ bool) error {
 				if !strings.HasPrefix(err.Error(), "invalid value \"wrong\"") {
 					t.Errorf("Expect an invalid value error, but got \"%v\"", err)
 				}

funcs.go

@@ -1,18 +1,24 @@
 package cli
 
 // An action to execute when the bash-completion flag is set
-type BashCompleteFn func(*Context)
+type BashCompleteFunc func(*Context)
 
 // An action to execute before any subcommands are run, but after the context is ready
 // If a non-nil error is returned, no subcommands are run
-type BeforeFn func(*Context) (int, error)
+type BeforeFunc func(*Context) (int, error)
 
 // An action to execute after any subcommands are run, but after the subcommand has finished
 // It is run even if Action() panics
-type AfterFn func(*Context) (int, error)
+type AfterFunc func(*Context) (int, error)
 
 // The action to execute when no subcommands are specified
-type ActionFn func(*Context) int
+type ActionFunc func(*Context) int
 
 // Execute this function if the proper command cannot be found
-type CommandNotFoundFn func(*Context, string)
+type CommandNotFoundFunc func(*Context, string)
+
+// Execute this function if an usage error occurs. This is useful for displaying
+// customized usage error messages.  This function is able to replace the
+// original error messages.  If this function is not set, the "Incorrect usage"
+// is displayed and the execution is interrupted.
+type OnUsageErrorFunc func(context *Context, err error, isSubcommand bool) error