This Go module contains cmder library package
which is a useful command builder for
spf13/cobra.
It helps you to easily build a cobra.Command hierarchy in the non-invasive and test-friendly way without any global variables or init().
Define each command's sturct that implements Cmder interface:
type App struct {
Bool bool // storage for flag -b
}
type AppAlpha struct {
*App // storage for parent Cmder (embedded)
String string // storage for flag -s
}
type AppAlphaOne struct {
*AppAlpha // storage for parent Cmder (embedded)
Int int // storage for flag -i
}Define each Comder's Cmd() method that returns *cobra.Command:
func (app *App) Cmd() *cobra.Command {
cmd := &cobra.Command{
Use: "app",
}
cmd.PersistentFlags().BoolVarP(&app.Bool, "bool", "b", false, "Bool flag")
return cmd
}
func (app *AppAlpha) Cmd() *cobra.Command {
cmd := &cobra.Command{
Use: "alpha",
}
cmd.PersistentFlags().StringVarP(&app.String, "string", "s", "", "String flag")
return cmd
}
func (app *AppAlphaOne) Cmd() *cobra.Command {
cmd := &cobra.Command{
Use: "one",
Run: app.Run,
}
cmd.Flags().IntVarP(&app.Int, "int", "i", 0, "Int flag")
return cmd
}
func (app *AppAlphaOne) Run(cmd *cobra.Command, args []string) {
fmt.Println(app.Bool, app.String, app.Int)
}Associate Cmders each other by defining a method that returns a child Cmder:
func (app *App) AppAlphaCmder() cmder.Cmder { return &AppAlpha{App: app} }
func (app *AppAlpha) AppAlphaOneCmder() cmder.Cmder { return &AppAlphaOne{AppAlpha: app} }Call cmder.Cmd() to collect and associate all cobra.Command instances:
func main() {
app := &App{}
cmd := cmder.Cmd(app)
err := cmd.Execute()
if err != nil {
os.Exit(1)
}
}Visit https://play.golang.org/p/zw4arxJfUkt to see and test the complete source code.
You can easily perform the Go standard unit tests on CLI apps with cobra-cmder.
See https://play.golang.org/p/tijvjDzmwqW for another example.
See the sample CLI app in cmd/sample for more comprehensive example.
Usage in real applications: