Use testify, write a couple more tests, and start a major refactor.

internal/mappingrules/rule_target_base.go

@@ -0,0 +1,35 @@
+package mappingrules
+
+import "github.com/holoplot/go-evdev"
+
+type RuleTargetBase struct {
+	DeviceName string
+	Device     *evdev.InputDevice
+	Code       evdev.EvCode
+	Inverted   bool
+}
+
+func NewRuleTargetBase(device_name string,
+	device *evdev.InputDevice,
+	code evdev.EvCode,
+	inverted bool) RuleTargetBase {
+
+	return RuleTargetBase{
+		DeviceName: device_name,
+		Device:     device,
+		Code:       code,
+		Inverted:   inverted,
+	}
+}
+
+func (target *RuleTargetBase) GetCode() evdev.EvCode {
+	return target.Code
+}
+
+func (target *RuleTargetBase) GetDeviceName() string {
+	return target.DeviceName
+}
+
+func (target *RuleTargetBase) GetDevice() *evdev.InputDevice {
+	return target.Device
+}