Early Hints

earlyhints.go

	// Early Hints
	app.Use(func(c *fiber.Ctx) error {
		if c.Method() != fiber.MethodGet ||
			!strings.Contains(c.Get("Accept", ""), "text/html") {
			return c.Next()
		}
		for _, entry := range Manifest {
			switch ext := strings.ToLower(filepath.Ext(entry.File)); ext {
			case ".js":
				c.Append("Link", fmt.Sprintf("</%s>; rel=preload; as=script", entry.File))
			case ".css":
				c.Append("Link", fmt.Sprintf("</%s>; rel=preload; as=style", entry.File))
			}
			for _, css := range entry.Css {
				c.Append("Link", fmt.Sprintf("</%s>; rel=preload; as=style", css))
			}
		}

		reqCtx := c.Context()
		if err := reqCtx.EarlyHints(); err != nil {
			zap.L().Warn("Early Hints failed", zap.Error(err))
		}

		return c.Next()
	})