improve tripperware request id (#17)

tripperware/request_id.go

@@ -19,9 +19,10 @@ func RequestId(config *request_id.Config) httpware.Tripperware {
 			}
 			if id == "" {
 				id = config.IdGenerator(req)
+				// add requestId header to current request
+				req.Header.Add(config.HeaderName, id)
 			}
 			r := req.WithContext(context.WithValue(req.Context(), config.HeaderName, id))
-			r.Header.Add(config.HeaderName, id)
 			return next.RoundTrip(r)
 		})
 	}

tripperware/request_id_test.go

@@ -2,8 +2,10 @@ package tripperware_test
 
 import (
 	"fmt"
+	"math/rand"
 	"net/http"
 	"net/http/httptest"
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -15,6 +17,14 @@ import (
 	"github.com/gol4ng/httpware/tripperware"
 )
 
+func TestMain(m *testing.M){
+	request_id.DefaultIdGenerator = request_id.NewRandomIdGenerator(
+		rand.New(request_id.NewLockedSource(rand.NewSource(1))),
+		10,
+	)
+	os.Exit(m.Run())
+}
+
 func TestRequestId(t *testing.T) {
 	roundTripperMock := &mocks.RoundTripper{}
 	req := httptest.NewRequest(http.MethodGet, "http://fake-addr", nil)
@@ -27,11 +37,13 @@ func TestRequestId(t *testing.T) {
 	roundTripperMock.On("RoundTrip", mock.AnythingOfType("*http.Request")).Return(resp, nil).Run(func(args mock.Arguments) {
 		innerReq := args.Get(0).(*http.Request)
 		assert.True(t, len(innerReq.Header.Get(request_id.HeaderName)) == 10)
+		assert.Equal(t, req.Header.Get(request_id.HeaderName), innerReq.Header.Get(request_id.HeaderName))
 	})
 
 	resp2, err := tripperware.RequestId(request_id.NewConfig())(roundTripperMock).RoundTrip(req)
 	assert.Nil(t, err)
 	assert.Equal(t, resp, resp2)
+	assert.Equal(t, "p1LGIehp1s", req.Header.Get(request_id.HeaderName))
 }
 
 func TestRequestIdCustom(t *testing.T) {
@@ -95,7 +107,7 @@ func ExampleRequestId() {
 		}
 	}()
 
-	_, _ = client.Get("http://localhost"+port+"/")
+	_, _ = client.Get("http://localhost" + port + "/")
 
 	// Output: server receive request with request id: my-generated-id
 }