qlog: introduce a basic tracer for non-connection events

qlog/tracer_test.go

@@ -0,0 +1,59 @@
+package qlog
+
+import (
+	"bytes"
+	"encoding/json"
+	"time"
+
+	"github.com/quic-go/quic-go/logging"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Tracing", func() {
+	var (
+		tracer *logging.Tracer
+		buf    *bytes.Buffer
+	)
+
+	BeforeEach(func() {
+		buf = &bytes.Buffer{}
+		tracer = NewTracer(nopWriteCloser(buf))
+	})
+
+	It("exports a trace that has the right metadata", func() {
+		tracer.Close()
+
+		m := make(map[string]interface{})
+		Expect(json.Unmarshal(buf.Bytes(), &m)).To(Succeed())
+		Expect(m).To(HaveKeyWithValue("qlog_version", "draft-02"))
+		Expect(m).To(HaveKey("title"))
+		Expect(m).To(HaveKey("trace"))
+		trace := m["trace"].(map[string]interface{})
+		Expect(trace).To(HaveKey(("common_fields")))
+		commonFields := trace["common_fields"].(map[string]interface{})
+		Expect(commonFields).ToNot(HaveKey("ODCID"))
+		Expect(commonFields).ToNot(HaveKey("group_id"))
+		Expect(commonFields).To(HaveKey("reference_time"))
+		referenceTime := time.Unix(0, int64(commonFields["reference_time"].(float64)*1e6))
+		Expect(referenceTime).To(BeTemporally("~", time.Now(), scaleDuration(10*time.Millisecond)))
+		Expect(commonFields).To(HaveKeyWithValue("time_format", "relative"))
+		Expect(trace).To(HaveKey("vantage_point"))
+		vantagePoint := trace["vantage_point"].(map[string]interface{})
+		Expect(vantagePoint).To(HaveKeyWithValue("type", "transport"))
+	})
+
+	Context("Events", func() {
+		It("records a generic event", func() {
+			tracer.Debug("foo", "bar")
+			tracer.Close()
+			entry := exportAndParseSingle(buf)
+			Expect(entry.Time).To(BeTemporally("~", time.Now(), scaleDuration(10*time.Millisecond)))
+			Expect(entry.Name).To(Equal("transport:foo"))
+			ev := entry.Event
+			Expect(ev).To(HaveLen(1))
+			Expect(ev).To(HaveKeyWithValue("details", "bar"))
+		})
+	})
+})