args.go

  1// Copyright 2013-2023 The Cobra Authors
  2//
  3// Licensed under the Apache License, Version 2.0 (the "License");
  4// you may not use this file except in compliance with the License.
  5// You may obtain a copy of the License at
  6//
  7//      http://www.apache.org/licenses/LICENSE-2.0
  8//
  9// Unless required by applicable law or agreed to in writing, software
 10// distributed under the License is distributed on an "AS IS" BASIS,
 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 12// See the License for the specific language governing permissions and
 13// limitations under the License.
 14
 15package cobra
 16
 17import (
 18	"fmt"
 19	"strings"
 20)
 21
 22type PositionalArgs func(cmd *Command, args []string) error
 23
 24// legacyArgs validation has the following behaviour:
 25// - root commands with no subcommands can take arbitrary arguments
 26// - root commands with subcommands will do subcommand validity checking
 27// - subcommands will always accept arbitrary arguments
 28func legacyArgs(cmd *Command, args []string) error {
 29	// no subcommand, always take args
 30	if !cmd.HasSubCommands() {
 31		return nil
 32	}
 33
 34	// root command with subcommands, do subcommand checking.
 35	if !cmd.HasParent() && len(args) > 0 {
 36		return fmt.Errorf("unknown command %q for %q%s", args[0], cmd.CommandPath(), cmd.findSuggestions(args[0]))
 37	}
 38	return nil
 39}
 40
 41// NoArgs returns an error if any args are included.
 42func NoArgs(cmd *Command, args []string) error {
 43	if len(args) > 0 {
 44		return fmt.Errorf("unknown command %q for %q", args[0], cmd.CommandPath())
 45	}
 46	return nil
 47}
 48
 49// OnlyValidArgs returns an error if there are any positional args that are not in
 50// the `ValidArgs` field of `Command`
 51func OnlyValidArgs(cmd *Command, args []string) error {
 52	if len(cmd.ValidArgs) > 0 {
 53		// Remove any description that may be included in ValidArgs.
 54		// A description is following a tab character.
 55		validArgs := make([]string, 0, len(cmd.ValidArgs))
 56		for _, v := range cmd.ValidArgs {
 57			validArgs = append(validArgs, strings.SplitN(v, "\t", 2)[0])
 58		}
 59		for _, v := range args {
 60			if !stringInSlice(v, validArgs) {
 61				return fmt.Errorf("invalid argument %q for %q%s", v, cmd.CommandPath(), cmd.findSuggestions(args[0]))
 62			}
 63		}
 64	}
 65	return nil
 66}
 67
 68// ArbitraryArgs never returns an error.
 69func ArbitraryArgs(cmd *Command, args []string) error {
 70	return nil
 71}
 72
 73// MinimumNArgs returns an error if there is not at least N args.
 74func MinimumNArgs(n int) PositionalArgs {
 75	return func(cmd *Command, args []string) error {
 76		if len(args) < n {
 77			return fmt.Errorf("requires at least %d arg(s), only received %d", n, len(args))
 78		}
 79		return nil
 80	}
 81}
 82
 83// MaximumNArgs returns an error if there are more than N args.
 84func MaximumNArgs(n int) PositionalArgs {
 85	return func(cmd *Command, args []string) error {
 86		if len(args) > n {
 87			return fmt.Errorf("accepts at most %d arg(s), received %d", n, len(args))
 88		}
 89		return nil
 90	}
 91}
 92
 93// ExactArgs returns an error if there are not exactly n args.
 94func ExactArgs(n int) PositionalArgs {
 95	return func(cmd *Command, args []string) error {
 96		if len(args) != n {
 97			return fmt.Errorf("accepts %d arg(s), received %d", n, len(args))
 98		}
 99		return nil
100	}
101}
102
103// RangeArgs returns an error if the number of args is not within the expected range.
104func RangeArgs(min int, max int) PositionalArgs {
105	return func(cmd *Command, args []string) error {
106		if len(args) < min || len(args) > max {
107			return fmt.Errorf("accepts between %d and %d arg(s), received %d", min, max, len(args))
108		}
109		return nil
110	}
111}
112
113// MatchAll allows combining several PositionalArgs to work in concert.
114func MatchAll(pargs ...PositionalArgs) PositionalArgs {
115	return func(cmd *Command, args []string) error {
116		for _, parg := range pargs {
117			if err := parg(cmd, args); err != nil {
118				return err
119			}
120		}
121		return nil
122	}
123}
124
125// ExactValidArgs returns an error if there are not exactly N positional args OR
126// there are any positional args that are not in the `ValidArgs` field of `Command`
127//
128// Deprecated: use MatchAll(ExactArgs(n), OnlyValidArgs) instead
129func ExactValidArgs(n int) PositionalArgs {
130	return MatchAll(ExactArgs(n), OnlyValidArgs)
131}