Add support for configurable target header for the request_id middleware

middleware/request_id_test.go

@@ -55,3 +55,34 @@ func TestRequestID_IDNotAltered(t *testing.T) {
 	_ = h(c)
 	assert.Equal(t, rec.Header().Get(echo.HeaderXRequestID), "<sample-request-id>")
 }
+
+func TestRequestIDConfigDifferentHeader(t *testing.T) {
+	e := echo.New()
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	rec := httptest.NewRecorder()
+	c := e.NewContext(req, rec)
+	handler := func(c echo.Context) error {
+		return c.String(http.StatusOK, "test")
+	}
+
+	rid := RequestIDWithConfig(RequestIDConfig{TargetHeader: echo.HeaderXCorrelationID})
+	h := rid(handler)
+	h(c)
+	assert.Len(t, rec.Header().Get(echo.HeaderXCorrelationID), 32)
+
+	// Custom generator and handler
+	customID := "customGenerator"
+	calledHandler := false
+	rid = RequestIDWithConfig(RequestIDConfig{
+		Generator:    func() string { return customID },
+		TargetHeader: echo.HeaderXCorrelationID,
+		RequestIDHandler: func(_ echo.Context, id string) {
+			calledHandler = true
+			assert.Equal(t, customID, id)
+		},
+	})
+	h = rid(handler)
+	h(c)
+	assert.Equal(t, rec.Header().Get(echo.HeaderXCorrelationID), "customGenerator")
+	assert.True(t, calledHandler)
+}