Cobra command groups for semantic help; root only aggregates

byob-command-shape.3 command-shape

Problem: mytool --help that dumps 30 commands in alphabetical order is a readability failure. Users have to know which command they want before the help is useful.

Idea: define a small set of cobra.Group entries on the root command (core, query, admin, setup, info). Each feature sets cmd.GroupID. Help groups related commands visually. The root command does nothing but import feature packages and wire their constructors into groups.

Tradeoffs: adding a new group is a root-command edit; resist the urge to invent a group per command. Three to six groups is the sweet spot. Avoid nesting groups arbitrarily deep.

Design

root := &cobra.Command{Use: "mytool"}
root.AddGroup(
    &cobra.Group{ID: "core",  Title: "Core commands:"},
    &cobra.Group{ID: "admin", Title: "Admin commands:"},
    &cobra.Group{ID: "info",  Title: "Info commands:"},
)

addTo := func(c *cobra.Command, group string) {
    c.GroupID = group
    root.AddCommand(c)
}

addTo(create.NewCmdCreate(f, nil), "core")
addTo(list.NewCmdList(f, nil),     "core")
addTo(doctor.NewCmdDoctor(f, nil), "info")