Naive implementation that always return min value

part/part.go

@@ -0,0 +1,54 @@
+package part
+
+import (
+	"github.com/cyrilix/robocar-base/mqttdevice"
+	mqtt "github.com/eclipse/paho.mqtt.golang"
+	"time"
+)
+
+type CommandValue struct {
+	Value      float64
+	Confidence float64
+}
+type Steering CommandValue
+type Throttle CommandValue
+
+func NewPart(pub mqttdevice.Publisher, throttleTopic string, minValue, maxValue float64) *ThrottlePart {
+	return &ThrottlePart{
+		pub:           pub,
+		throttleTopic: throttleTopic,
+		minThrottle:   minValue,
+		maxThrottle:   maxValue,
+	}
+
+}
+
+type ThrottlePart struct {
+	client                   mqtt.Client
+	pub                      mqttdevice.Publisher
+	throttleTopic            string
+	minThrottle, maxThrottle float64
+	cancel                   chan interface{}
+}
+
+func (p *ThrottlePart) Start() error {
+	p.cancel = make(chan interface{})
+	ticker := time.NewTicker(500 * time.Millisecond)
+	for {
+
+		p.pub.Publish(p.throttleTopic, mqttdevice.NewMqttValue(Throttle{
+			Value:      p.minThrottle,
+			Confidence: 1.0,
+		}))
+
+		select {
+		case <-ticker.C:
+		case <-p.cancel:
+			break
+		}
+	}
+}
+
+func (p *ThrottlePart) Stop() {
+	close(p.cancel)
+}

part/part_test.go

@@ -0,0 +1,36 @@
+package part
+
+import (
+	"encoding/json"
+	"github.com/cyrilix/robocar-base/testtools"
+	"testing"
+	"time"
+)
+
+func TestDefaultThrottle(t *testing.T){
+	throttleTopic := "topic/throttle"
+	minValue := 0.56
+
+	pub := testtools.NewFakePublisher()
+	p := NewPart(pub, throttleTopic, minValue, 1.)
+
+	go p.Start()
+	defer p.Stop()
+
+	time.Sleep(1 * time.Millisecond)
+
+	mqttValue := pub.PublishedEvent(throttleTopic)
+	var throttle Throttle
+	err := json.Unmarshal(mqttValue, &throttle)
+	if err != nil {
+		t.Errorf("unable to unmarshall response: %v", err)
+		t.Fail()
+	}
+
+	if throttle.Value != minValue {
+		t.Errorf("bad throttle value: %v, wants %v", throttle.Value, minValue)
+	}
+	if throttle.Confidence != 1. {
+		t.Errorf("bad throtlle confidence: %v, wants %v", throttle.Confidence, 1.)
+	}
+}