feat(go): add nats kafka ingest bridge

go/vehicle-gateway/cmd/nats-kafka-bridge/main_test.go

@@ -0,0 +1,75 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"testing"
+
+	"github.com/segmentio/kafka-go"
+
+	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/envelope"
+)
+
+func TestBridgeBatchWritesKafkaThenAcks(t *testing.T) {
+	env := envelope.FrameEnvelope{Protocol: envelope.ProtocolJT808, Phone: "13307795425", MessageID: "0x0200"}
+	payload, err := json.Marshal(env)
+	if err != nil {
+		t.Fatal(err)
+	}
+	writer := &recordingBridgeWriter{}
+	acked := 0
+
+	err = bridgeBatch(context.Background(), writer, []bridgeMessage{
+		{subject: "vehicle.raw.jt808.v1", data: payload, ack: func() error {
+			acked++
+			return nil
+		}},
+	}, map[string]string{"vehicle.raw.jt808.v1": "vehicle.raw.jt808.v1"})
+	if err != nil {
+		t.Fatalf("bridgeBatch() error = %v", err)
+	}
+	if len(writer.messages) != 1 {
+		t.Fatalf("kafka writes = %d, want 1", len(writer.messages))
+	}
+	if got, want := writer.messages[0].Topic, "vehicle.raw.jt808.v1"; got != want {
+		t.Fatalf("topic = %q, want %q", got, want)
+	}
+	if got, want := string(writer.messages[0].Key), "JT808:13307795425"; got != want {
+		t.Fatalf("key = %q, want %q", got, want)
+	}
+	if acked != 1 {
+		t.Fatalf("acks = %d, want 1", acked)
+	}
+}
+
+func TestBridgeBatchDoesNotAckWhenKafkaFails(t *testing.T) {
+	writer := &recordingBridgeWriter{err: errors.New("kafka unavailable")}
+	acked := 0
+
+	err := bridgeBatch(context.Background(), writer, []bridgeMessage{
+		{subject: "vehicle.event.unified.v1", data: []byte(`{"protocol":"JT808"}`), ack: func() error {
+			acked++
+			return nil
+		}},
+	}, map[string]string{"vehicle.event.unified.v1": "vehicle.event.unified.v1"})
+	if err == nil {
+		t.Fatal("bridgeBatch() error is nil, want kafka error")
+	}
+	if acked != 0 {
+		t.Fatalf("acks = %d, want 0", acked)
+	}
+}
+
+type recordingBridgeWriter struct {
+	messages []kafka.Message
+	err      error
+}
+
+func (w *recordingBridgeWriter) WriteMessages(_ context.Context, messages ...kafka.Message) error {
+	if w.err != nil {
+		return w.err
+	}
+	w.messages = append(w.messages, messages...)
+	return nil
+}