qmk-rgb/cmd/qmk-rgb-tool/arity_test.go

package main

import (
	"strings"
	"testing"

	"github.com/spf13/cobra"
)

// `list` takes nothing. Without a declared arity cobra applies arbitraryArgs, so
// a stray token yielded exit 0 and the command looked like it had done its work —
// a caller could believe a lighting change happened when the argument was silently
// dropped.
func TestZeroArgCommandsRejectStrayTokens(t *testing.T) {
	cmds := map[string]*cobra.Command{
		"list": NewProfileListCmd(),
	}

	for name, cmd := range cmds {
		t.Run(name, func(t *testing.T) {
			err := cmd.ValidateArgs([]string{"unexpected-arg"})
			if err == nil {
				t.Errorf("%s accepted an argument, want it rejected", name)
				return
			}
			if !strings.Contains(err.Error(), "unexpected-arg") {
				t.Errorf("%s error = %q, want it to name the offending argument", name, err)
			}
		})
	}
}

// Rejecting extras must not break the no-argument case.
func TestZeroArgCommandsAcceptNoArgs(t *testing.T) {
	cmds := map[string]*cobra.Command{
		"list": NewProfileListCmd(),
	}

	for name, cmd := range cmds {
		t.Run(name, func(t *testing.T) {
			if err := cmd.ValidateArgs(nil); err != nil {
				t.Errorf("%s rejected the empty argument list: %v", name, err)
			}
		})
	}
}

// A command whose arguments are a zone and a value takes exactly those two, and
// refuses a third: an extra token means the invocation is not the one the user
// meant, and carrying on with the first two is a guess.
func TestTwoArgCommandsKeepTheirArity(t *testing.T) {
	cmds := map[string]*cobra.Command{
		"brightness": NewBrightnessCmd(),
		"speed":      NewSpeedCmd(),
		"color":      NewColorCmd(),
	}

	for name, cmd := range cmds {
		t.Run(name, func(t *testing.T) {
			if err := cmd.ValidateArgs([]string{"logo", "160"}); err != nil {
				t.Errorf("%s rejected its arguments: %v", name, err)
			}
			if err := cmd.ValidateArgs([]string{"160"}); err == nil {
				t.Errorf("%s accepted one argument, want a zone and a value", name)
			}
			if err := cmd.ValidateArgs([]string{"logo", "160", "extra"}); err == nil {
				t.Errorf("%s accepted three arguments, want exactly two", name)
			}
		})
	}
}

// A zone is an argument and not a flag, so the count of a command that writes
// lighting is the thing that keeps it from writing every channel by accident.
func TestZoneCommandsRejectAMissingZone(t *testing.T) {
	cmds := map[string]*cobra.Command{
		"enable":  NewEnableCmd(),
		"disable": NewDisableCmd(),
	}

	for name, cmd := range cmds {
		t.Run(name, func(t *testing.T) {
			if err := cmd.ValidateArgs([]string{"logo"}); err != nil {
				t.Errorf("%s rejected a zone: %v", name, err)
			}
			err := cmd.ValidateArgs(nil)
			if err == nil {
				t.Fatalf("%s accepted no arguments, want the zone to be required", name)
			}
			if !strings.Contains(err.Error(), "zone") {
				t.Errorf("%s error = %q, want it to name the missing zone", name, err)
			}
		})
	}
}

// `effect` reads with one argument and writes with two, so the count is what tells
// the two apart, and either count alone has to be accepted.
func TestEffectTakesAZoneAndOptionallyAName(t *testing.T) {
	cmd := NewEffectCmd()

	if err := cmd.ValidateArgs([]string{"logo"}); err != nil {
		t.Errorf("effect rejected a zone on its own: %v", err)
	}
	if err := cmd.ValidateArgs([]string{"logo", "wave"}); err != nil {
		t.Errorf("effect rejected a zone and a name: %v", err)
	}
	if err := cmd.ValidateArgs(nil); err == nil {
		t.Error("effect accepted no arguments, want a zone to be required")
	}
	if err := cmd.ValidateArgs([]string{"logo", "wave", "extra"}); err == nil {
		t.Error("effect accepted three arguments, want at most two")
	}
}

// `info` reads every channel when it is given nothing and one zone when it is
// given one. Both are requests, so neither is a stray token.
func TestInfoTakesAtMostAZone(t *testing.T) {
	cmd := NewInfoCmd()

	if err := cmd.ValidateArgs(nil); err != nil {
		t.Errorf("info rejected no arguments: %v", err)
	}
	if err := cmd.ValidateArgs([]string{"logo"}); err != nil {
		t.Errorf("info rejected a zone: %v", err)
	}
	if err := cmd.ValidateArgs([]string{"logo", "side"}); err == nil {
		t.Error("info accepted two arguments, want one zone or none")
	}
}

// A list of zones is one argument, so `info logo,side` is one zone naming two
// channels and not two arguments.
func TestInfoTakesAZoneListAsOneArgument(t *testing.T) {
	cmd := NewInfoCmd()

	if err := cmd.ValidateArgs([]string{"logo,side"}); err != nil {
		t.Errorf("info rejected a comma separated zone list: %v", err)
	}
}