Add ability to register commands

command/command_test.go

@@ -1,6 +1,9 @@
 package command
 
-import "testing"
+import (
+	"fmt"
+	"testing"
+)
 
 func TestCommandDefault(t *testing.T) {
 	var (
@@ -17,3 +20,20 @@ func TestCommandDefault(t *testing.T) {
 		t.Fatal("wrong command output")
 	}
 }
+
+func TestCommandRegister(t *testing.T) {
+	cmds := Commands{make(map[string]cmdfunc)}
+
+	cmds.Register("foo", func() error { return fmt.Errorf("registered command") })
+
+	cmd := cmds.Find("foo")
+
+	err := cmd()
+	if err == nil {
+		t.Fatal("cmd was not found")
+	}
+
+	if err.Error() != "registered command" {
+		t.Fatal("wrong command output")
+	}
+}