1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
10. 10
11. 11
12. 12
13. 13
14. 14
15. 15
16. 16
17. 17
18. 18
19. 19
20. 20
21. 21
22. 22
23. 23
24. 24
25. 25
26. 26
27. 27
28. 28
29. 29
30. 30
31. 31
32. 32
33. 33
34. 34
35. 35
36. 36
37. 37
38. 38
39. 39
40. 40
41. 41
42. 42
43. 43
44. 44
45. 45
46. 46
47. 47
48. 48
49. 49
50. 50
51. 51
52. 52
53. 53
54. 54
55. 55
56. 56
57. 57
58. 58
59. 59
60. 60
61. 61
62. 62
63. 63
64. 64
65. 65
66. 66
67. 67
68. 68
69. 69
70. 70
71. 71
72. 72
73. 73
74. 74
75. 75
76. 76
77. 77
78. 78
79. 79
80. 80
81. 81
82. 82
83. 83
84. 84
85. 85
86. 86
87. 87
88. 88
89. 89
90. 90
91. 91
92. 92
93. 93
94. 94
95. 95
96. 96
97. 97
98. 98
99. 99
100. 100
101. 101
102. 102
103. 103
104. 104
105. 105
106. 106
107. 107
108. 108
109. 109
110. 110
111. 111
112. 112
113. 113
114. 114
115. 115

package cli

import (
	"fmt"
	"io"
	"os"
	"strings"
)

// OsExiter is the function used when the app exits. If not set defaults to os.Exit.
var OsExiter = os.Exit

// ErrWriter is used to write errors to the user. This can be anything
// implementing the io.Writer interface and defaults to os.Stderr.
var ErrWriter io.Writer = os.Stderr

// MultiError is an error that wraps multiple errors.
type MultiError struct {
	Errors []error
}

// NewMultiError creates a new MultiError. Pass in one or more errors.
func NewMultiError(err ...error) MultiError {
	return MultiError{Errors: err}
}

// Error implements the error interface.
func (m MultiError) Error() string {
	errs := make([]string, len(m.Errors))
	for i, err := range m.Errors {
		errs[i] = err.Error()
	}

	return strings.Join(errs, "\n")
}

type ErrorFormatter interface {
	Format(s fmt.State, verb rune)
}

// ExitCoder is the interface checked by `App` and `Command` for a custom exit
// code
type ExitCoder interface {
	error
	ExitCode() int
}

// ExitError fulfills both the builtin `error` interface and `ExitCoder`
type ExitError struct {
	exitCode int
	message  interface{}
}

// NewExitError makes a new *ExitError
func NewExitError(message interface{}, exitCode int) *ExitError {
	return &ExitError{
		exitCode: exitCode,
		message:  message,
	}
}

// Error returns the string message, fulfilling the interface required by
// `error`
func (ee *ExitError) Error() string {
	return fmt.Sprintf("%v", ee.message)
}

// ExitCode returns the exit code, fulfilling the interface required by
// `ExitCoder`
func (ee *ExitError) ExitCode() int {
	return ee.exitCode
}

// HandleExitCoder checks if the error fulfills the ExitCoder interface, and if
// so prints the error to stderr (if it is non-empty) and calls OsExiter with the
// given exit code.  If the given error is a MultiError, then this func is
// called on all members of the Errors slice and calls OsExiter with the last exit code.
func HandleExitCoder(err error) {
	if err == nil {
		return
	}

	if exitErr, ok := err.(ExitCoder); ok {
		if err.Error() != "" {
			if _, ok := exitErr.(ErrorFormatter); ok {
				fmt.Fprintf(ErrWriter, "%+v\n", err)
			} else {
				fmt.Fprintln(ErrWriter, err)
			}
		}
		OsExiter(exitErr.ExitCode())
		return
	}

	if multiErr, ok := err.(MultiError); ok {
		code := handleMultiError(multiErr)
		OsExiter(code)
		return
	}
}

func handleMultiError(multiErr MultiError) int {
	code := 1
	for _, merr := range multiErr.Errors {
		if multiErr2, ok := merr.(MultiError); ok {
			code = handleMultiError(multiErr2)
		} else {
			fmt.Fprintln(ErrWriter, merr)
			if exitErr, ok := merr.(ExitCoder); ok {
				code = exitErr.ExitCode()
			}
		}
	}
	return code
}