spf13--cobra/args.go
Brian Fitzgerald d8e244d161 Updates NoArgs to also report invalid argument
NoArgs currently reports "unknown command" in all cases, which
can be is a little misleading to the user if there are no
subcommands. Change it as follows

- if subcommands and one extra arg, say "unknown command"
- otherwise, say "invalid argument(s)" and show all extra args

This should produce more meaningful error messages to users, and
works for both the root and sub-commands.
2018-04-06 13:13:55 -07:00

98 lines
2.9 KiB
Go

package cobra
import (
"fmt"
"strings"
)
type PositionalArgs func(cmd *Command, args []string) error
// Legacy arg validation has the following behaviour:
// - root commands with no subcommands can take arbitrary arguments
// - root commands with subcommands will do subcommand validity checking
// - subcommands will always accept arbitrary arguments
func legacyArgs(cmd *Command, args []string) error {
// no subcommand, always take args
if !cmd.HasSubCommands() {
return nil
}
// root command with subcommands, do subcommand checking.
if !cmd.HasParent() && len(args) > 0 {
return fmt.Errorf("unknown command %q for %q%s", args[0], cmd.CommandPath(), cmd.findSuggestions(args[0]))
}
return nil
}
// NoArgs returns an error if any args are included.
func NoArgs(cmd *Command, args []string) error {
if len(args) == 0 {
return nil
}
// If we have exactly one argument and we have sub-commands, then assume the user
// made a typo on a subcommand, or typed the wrong subcommand
if len(args) == 1 && len(cmd.commands) > 0 {
return fmt.Errorf("unknown command %q for %q", args[0], cmd.CommandPath())
}
// Otherwise, assume that this is one or more invalid arguments
return fmt.Errorf("invalid argument(s) %q for %q", strings.Join(args, " "), cmd.CommandPath())
}
// OnlyValidArgs returns an error if any args are not in the list of ValidArgs.
func OnlyValidArgs(cmd *Command, args []string) error {
if len(cmd.ValidArgs) > 0 {
for _, v := range args {
if !stringInSlice(v, cmd.ValidArgs) {
return fmt.Errorf("invalid argument %q for %q%s", v, cmd.CommandPath(), cmd.findSuggestions(args[0]))
}
}
}
return nil
}
// ArbitraryArgs never returns an error.
func ArbitraryArgs(cmd *Command, args []string) error {
return nil
}
// MinimumNArgs returns an error if there is not at least N args.
func MinimumNArgs(n int) PositionalArgs {
return func(cmd *Command, args []string) error {
if len(args) < n {
return fmt.Errorf("requires at least %d arg(s), only received %d", n, len(args))
}
return nil
}
}
// MaximumNArgs returns an error if there are more than N args.
func MaximumNArgs(n int) PositionalArgs {
return func(cmd *Command, args []string) error {
if len(args) > n {
return fmt.Errorf("accepts at most %d arg(s), received %d", n, len(args))
}
return nil
}
}
// ExactArgs returns an error if there are not exactly n args.
func ExactArgs(n int) PositionalArgs {
return func(cmd *Command, args []string) error {
if len(args) != n {
return fmt.Errorf("accepts %d arg(s), received %d", n, len(args))
}
return nil
}
}
// RangeArgs returns an error if the number of args is not within the expected range.
func RangeArgs(min int, max int) PositionalArgs {
return func(cmd *Command, args []string) error {
if len(args) < min || len(args) > max {
return fmt.Errorf("accepts between %d and %d arg(s), received %d", min, max, len(args))
}
return nil
}
}