fix(go): protect kafka message processing during shutdown

go/vehicle-gateway/cmd/stat-writer/main_test.go

@@ -0,0 +1,70 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"testing"
+
+	"github.com/segmentio/kafka-go"
+
+	"lingniu-vehicle-ingest/go/vehicle-gateway/internal/envelope"
+)
+
+func TestProcessStatMessageUsesUncancelledContextForAppendAndCommit(t *testing.T) {
+	parent, cancel := context.WithCancel(context.Background())
+	cancel()
+
+	env := envelope.FrameEnvelope{
+		Protocol:     envelope.ProtocolJT808,
+		MessageID:    "0x0200",
+		Phone:        "13307795425",
+		EventTimeMS:  1782918600000,
+		ReceivedAtMS: 1782918600000,
+		ParseStatus:  envelope.ParseOK,
+	}
+	payload, err := json.Marshal(env)
+	if err != nil {
+		t.Fatal(err)
+	}
+	appender := &contextCheckingStatAppender{}
+	committer := &contextCheckingStatCommitter{}
+
+	processStatMessage(parent, discardStatLogger{}, appender, committer, kafka.Message{Value: payload})
+
+	if appender.ctxErr != nil {
+		t.Fatalf("appender saw cancelled context: %v", appender.ctxErr)
+	}
+	if committer.ctxErr != nil {
+		t.Fatalf("committer saw cancelled context: %v", committer.ctxErr)
+	}
+	if appender.count != 1 || committer.count != 1 {
+		t.Fatalf("appends=%d commits=%d", appender.count, committer.count)
+	}
+}
+
+type contextCheckingStatAppender struct {
+	ctxErr error
+	count  int
+}
+
+func (a *contextCheckingStatAppender) Append(ctx context.Context, _ envelope.FrameEnvelope) error {
+	a.ctxErr = ctx.Err()
+	a.count++
+	return a.ctxErr
+}
+
+type contextCheckingStatCommitter struct {
+	ctxErr error
+	count  int
+}
+
+func (c *contextCheckingStatCommitter) CommitMessages(ctx context.Context, _ ...kafka.Message) error {
+	c.ctxErr = ctx.Err()
+	c.count++
+	return c.ctxErr
+}
+
+type discardStatLogger struct{}
+
+func (discardStatLogger) Error(string, ...any) {}
+func (discardStatLogger) Warn(string, ...any)  {}