Merge pull request #250 from axw/v2-url-leading-slash

model: add leading slash to URL path if missing

model/marshal.go

@@ -84,6 +84,9 @@ func (v *HTTPSpanContext) marshalURL(w *fastjson.Writer) bool {
 	if v.URL.Path == "" {
 		w.RawByte('/')
 	} else {
+		if v.URL.Path[0] != '/' {
+			w.RawByte('/')
+		}
 		w.StringContents(v.URL.Path)
 	}
 	if v.URL.RawQuery != "" {
@@ -122,14 +125,18 @@ func (v *URL) MarshalFastJSON(w *fastjson.Writer) {
 		w.String(v.Hostname)
 	}
 	if v.Path != "" {
-		const prefix = ",\"pathname\":"
+		const prefix = `,"pathname":"`
 		if first {
 			first = false
 			w.RawString(prefix[1:])
 		} else {
 			w.RawString(prefix)
 		}
-		w.String(v.Path)
+		if v.Path[0] != '/' {
+			w.RawByte('/')
+		}
+		w.StringContents(v.Path)
+		w.RawByte('"')
 	}
 	if v.Port != "" {
 		const prefix = ",\"port\":"
@@ -221,6 +228,9 @@ func (v *URL) marshalFullURL(w *fastjson.Writer, scheme []byte) bool {
 		w.RawByte(':')
 		w.StringContents(v.Port)
 	}
+	if !strings.HasPrefix(v.Path, "/") {
+		w.RawByte('/')
+	}
 	w.StringContents(v.Path)
 	if v.Search != "" {
 		w.RawByte('?')

model/marshal_test.go

@@ -427,6 +427,50 @@ func TestMarshalURL(t *testing.T) {
 	assert.Equal(t, in, out)
 }
 
+func TestMarshalURLPathLeadingSlashMissing(t *testing.T) {
+	in := model.URL{
+		Path:     "foo",
+		Search:   "abc=def",
+		Hostname: "testing.invalid",
+		Port:     "999",
+		Protocol: "http",
+	}
+
+	var w fastjson.Writer
+	in.MarshalFastJSON(&w)
+
+	var out model.URL
+	err := json.Unmarshal(w.Bytes(), &out)
+	require.NoError(t, err)
+
+	assert.Equal(t, "http://testing.invalid:999/foo?abc=def", out.Full)
+	out.Full = ""
+
+	// Leading slash should have been added during marshalling. We do it
+	// here rather than when building the model to avoid allocation.
+	in.Path = "/foo"
+
+	assert.Equal(t, in, out)
+}
+
+func TestMarshalHTTPSpanContextURLPathLeadingSlashMissing(t *testing.T) {
+	httpSpanContext := model.HTTPSpanContext{
+		URL: mustParseURL("http://testing.invalid:8000/path?query#fragment"),
+	}
+	httpSpanContext.URL.Path = "path"
+
+	var w fastjson.Writer
+	httpSpanContext.MarshalFastJSON(&w)
+
+	var out model.HTTPSpanContext
+	err := json.Unmarshal(w.Bytes(), &out)
+	require.NoError(t, err)
+
+	// Leading slash should have been added during marshalling.
+	httpSpanContext.URL.Path = "/path"
+	assert.Equal(t, httpSpanContext.URL, out.URL)
+}
+
 func TestTransactionUnmarshalJSON(t *testing.T) {
 	tx := fakeTransaction()
 	var w fastjson.Writer