Path wrong when cached response

[Fesaa]

If a method is returned early(?) by a cache middleware, it'll be added by the complete path in the metric. Instead of with the generic path.

This code can reproduce it easily;

func TestFiberProm(t *testing.T) {

	app := fiber.New()
	prom := fiberprometheus.New("cache-path-test")
	prom.RegisterAt(app, "/metrics")
	app.Use(prom.Middleware)

	app.Use(cache.New())

	app.Get("/:name", func(c *fiber.Ctx) error {
		return c.SendString("Hello, World!")
	})

	req1 := httptest.NewRequest("GET", "/one", nil)
	resp, err := app.Test(req1, -1)
	if err != nil {
		t.Fatal(err)
	}
	if resp.StatusCode != 200 {
		t.FailNow()
	}

	resp, err = app.Test(req1, -1)
	if err != nil {
		t.Fatal(err)
	}
	if resp.StatusCode != 200 {
		t.FailNow()
	}

	req := httptest.NewRequest("GET", "/metrics", nil)
	resp, _ = app.Test(req, -1)
	defer resp.Body.Close()
	body, _ := io.ReadAll(resp.Body)
	got := string(body)

	want := "http_requests_total{method=\"GET\",path=\"/:name\",service=\"cache-path-test\",status_code=\"200\"} 2"
	if !strings.Contains(got, want) {
		t.Errorf("got %s; want %s", got, want)
	}

	dontWant := "http_requests_total{method=\"GET\",path=\"/one\",service=\"cache-path-test\",status_code=\"200\"} 1"
	if strings.Contains(got, dontWant) {
		t.Errorf("got included %s, while it shoudln't", dontWant)
	}
}

I understand this may not be trivial to solve, and I can image it not really be solvable at all. Sadly, I don't know the internal of fiber good enough to gauge at this or take a stab.