generated from bep/golibtemplate
-
-
Notifications
You must be signed in to change notification settings - Fork 3
/
simplecobra.go
256 lines (213 loc) · 5.85 KB
/
simplecobra.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
package simplecobra
import (
"context"
"errors"
"fmt"
"strings"
"github.com/spf13/cobra"
)
// Commander is the interface that must be implemented by all commands.
type Commander interface {
// The name of the command.
Name() string
// Init is called when the cobra command is created.
// This is where the flags, short and long description etc. can be added.
Init(*Commandeer) error
// PreRun called on all ancestors and the executing command itself, before execution, starting from the root.
// This is the place to evaluate flags and set up the this Commandeer.
// The runner Commandeer holds the currently running command, which will be PreRun last.
PreRun(this, runner *Commandeer) error
// The command execution.
Run(ctx context.Context, cd *Commandeer, args []string) error
// Commands returns the sub commands, if any.
Commands() []Commander
}
// New creates a new Executer from the command tree in Commander.
func New(rootCmd Commander) (*Exec, error) {
rootCd := &Commandeer{
Command: rootCmd,
}
rootCd.Root = rootCd
// Add all commands recursively.
var addCommands func(cd *Commandeer, cmd Commander)
addCommands = func(cd *Commandeer, cmd Commander) {
cd2 := &Commandeer{
Root: rootCd,
Parent: cd,
Command: cmd,
}
cd.commandeers = append(cd.commandeers, cd2)
for _, c := range cmd.Commands() {
addCommands(cd2, c)
}
}
for _, cmd := range rootCmd.Commands() {
addCommands(rootCd, cmd)
}
if err := rootCd.compile(); err != nil {
return nil, err
}
return &Exec{c: rootCd}, nil
}
// Commandeer holds the state of a command and its subcommands.
type Commandeer struct {
Command Commander
CobraCommand *cobra.Command
Root *Commandeer
Parent *Commandeer
commandeers []*Commandeer
}
func (c *Commandeer) init() error {
// Collect all ancestors including self.
var ancestors []*Commandeer
{
cd := c
for cd != nil {
ancestors = append(ancestors, cd)
cd = cd.Parent
}
}
// Init all of them starting from the root.
for i := len(ancestors) - 1; i >= 0; i-- {
cd := ancestors[i]
if err := cd.Command.PreRun(cd, c); err != nil {
return err
}
}
return nil
}
type runErr struct {
error
}
func (c *Commandeer) compile() error {
useCommandFlagsArgs := "[command] [flags]"
if len(c.commandeers) == 0 {
useCommandFlagsArgs = "[flags] [args]"
}
c.CobraCommand = &cobra.Command{
Use: fmt.Sprintf("%s %s", c.Command.Name(), useCommandFlagsArgs),
RunE: func(cmd *cobra.Command, args []string) error {
if err := c.Command.Run(cmd.Context(), c, args); err != nil {
return &runErr{error: err}
}
return nil
},
PreRunE: func(cmd *cobra.Command, args []string) error {
return c.init()
},
SilenceErrors: true,
SilenceUsage: true,
SuggestionsMinimumDistance: 2,
}
// This is where the flags, short and long description etc. are added
if err := c.Command.Init(c); err != nil {
return err
}
// Add commands recursively.
for _, cc := range c.commandeers {
if err := cc.compile(); err != nil {
return err
}
c.CobraCommand.AddCommand(cc.CobraCommand)
}
return nil
}
// Exec provides methods to execute the command tree.
type Exec struct {
c *Commandeer
}
// Execute executes the command tree starting from the root command.
// The args are usually filled with os.Args[1:].
func (r *Exec) Execute(ctx context.Context, args []string) (*Commandeer, error) {
if args == nil {
// Cobra falls back to os.Args[1:] if args is nil.
args = []string{}
}
r.c.CobraCommand.SetArgs(args)
cobraCommand, err := r.c.CobraCommand.ExecuteContextC(ctx)
var cd *Commandeer
if cobraCommand != nil {
if err == nil {
err = checkArgs(cobraCommand, args)
}
// Find the commandeer that was executed.
var find func(*cobra.Command, *Commandeer) *Commandeer
find = func(what *cobra.Command, in *Commandeer) *Commandeer {
if in.CobraCommand == what {
return in
}
for _, in2 := range in.commandeers {
if found := find(what, in2); found != nil {
return found
}
}
return nil
}
cd = find(cobraCommand, r.c)
}
return cd, wrapErr(err)
}
// CommandError is returned when a command fails because of a user error (unknown command, invalid flag etc.).
// All other errors comes from the execution of the command.
type CommandError struct {
Err error
}
// Error implements error.
func (e *CommandError) Error() string {
return fmt.Sprintf("command error: %v", e.Err)
}
// Is reports whether e is of type *CommandError.
func (*CommandError) Is(e error) bool {
_, ok := e.(*CommandError)
return ok
}
// IsCommandError reports whether any error in err's tree matches CommandError.
func IsCommandError(err error) bool {
return errors.Is(err, &CommandError{})
}
func wrapErr(err error) error {
if err == nil {
return nil
}
if rerr, ok := err.(*runErr); ok {
return rerr.error
}
// All other errors are coming from Cobra.
return &CommandError{Err: err}
}
// Cobra only does suggestions for the root command.
// See https://github.com/spf13/cobra/pull/1500
func checkArgs(cmd *cobra.Command, args []string) error {
// no subcommand, always take args.
if !cmd.HasSubCommands() {
return nil
}
var commandName string
for _, arg := range args {
if strings.HasPrefix(arg, "-") {
break
}
commandName = arg
}
if commandName == "" || cmd.Name() == commandName {
return nil
}
// Also check the aliases.
if cmd.HasAlias(commandName) {
return nil
}
return fmt.Errorf("unknown command %q for %q%s", args[1], cmd.CommandPath(), findSuggestions(cmd, commandName))
}
func findSuggestions(cmd *cobra.Command, arg string) string {
if cmd.DisableSuggestions {
return ""
}
suggestionsString := ""
if suggestions := cmd.SuggestionsFor(arg); len(suggestions) > 0 {
suggestionsString += "\n\nDid you mean this?\n"
for _, s := range suggestions {
suggestionsString += fmt.Sprintf("\t%v\n", s)
}
}
return suggestionsString
}