spf13--cobra/args.go
Daniel Nephin f20b4e9c32 Refactor TakesArgs to use an interface for arg validation.
Fix some typos in README and comments.
Move arg validation to after flag validation so that the help flag is run first.
Pass the same args to ValidateArgs as the Run methods receive.
Update README.

Signed-off-by: Daniel Nephin <dnephin@gmail.com>
2017-07-23 09:57:27 +02:00

99 lines
2.6 KiB
Go

package cobra
import (
"fmt"
)
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 fmt.Errorf("unknown command %q for %q", args[0], cmd.CommandPath())
}
return nil
}
// 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
}
func stringInSlice(a string, list []string) bool {
for _, b := range list {
if b == a {
return true
}
}
return false
}
// 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
}
}