pkg/earlydata: address comments

middleware/earlydata/config.go

@@ -4,8 +4,18 @@ import (
 	"github.com/gofiber/fiber/v3"
 )
 
+const (
+	DefaultHeaderName      = "Early-Data"
+	DefaultHeaderTrueValue = "1"
+)
+
 // Config defines the config for middleware.
 type Config struct {
+	// Next defines a function to skip this middleware when returned true.
+	//
+	// Optional. Default: nil
+	Next func(c fiber.Ctx) bool
+
 	// IsEarlyData returns whether the request is an early-data request.
 	//
 	// Optional. Default: a function which checks if the "Early-Data" request header equals "1".
@@ -25,7 +35,7 @@ type Config struct {
 // ConfigDefault is the default config
 var ConfigDefault = Config{
 	IsEarlyData: func(c fiber.Ctx) bool {
-		return c.Get("Early-Data") == "1"
+		return c.Get(DefaultHeaderName) == DefaultHeaderTrueValue
 	},
 
 	AllowEarlyData: func(c fiber.Ctx) bool {

middleware/earlydata/earlydata.go

@@ -20,6 +20,11 @@ func New(config ...Config) fiber.Handler {
 
 	// Return new handler
 	return func(c fiber.Ctx) error {
+		// Don't execute middleware if Next returns true
+		if cfg.Next != nil && cfg.Next(c) {
+			return c.Next()
+		}
+
 		// Abort if we can't trust the early-data header
 		if !c.IsProxyTrusted() {
 			return cfg.Error