refactor: fix lint errors; improve error handling

internal/net/gphttp/loadbalancer/round_robin.go

@@ -8,7 +8,7 @@ import (
 )
 
 type roundRobin struct {
-	index atomic.Uint32
+	index atomic.Uint64
 }
 
 var _ impl = (*roundRobin)(nil)
@@ -21,6 +21,6 @@ func (lb *roundRobin) ChooseServer(srvs types.LoadBalancerServers, r *http.Reque
 	if len(srvs) == 0 {
 		return nil
 	}
-	index := (lb.index.Add(1) - 1) % uint32(len(srvs))
+	index := (lb.index.Add(1) - 1) % uint64(len(srvs))
 	return srvs[index]
 }

internal/net/gphttp/middleware/captcha/hcaptcha.go

@@ -22,12 +22,14 @@ type HcaptchaProvider struct {
 	Secret  string `json:"secret" validate:"required"`
 }
 
-// https://docs.hcaptcha.com/#content-security-policy-settings
+// CSPDirectives returns the CSP directives for the Hcaptcha provider.
+// See: https://docs.hcaptcha.com/#content-security-policy-settings
 func (p *HcaptchaProvider) CSPDirectives() []string {
 	return []string{"script-src", "frame-src", "style-src", "connect-src"}
 }
 
-// https://docs.hcaptcha.com/#content-security-policy-settings
+// CSPSources returns the CSP sources for the Hcaptcha provider.
+// See: https://docs.hcaptcha.com/#content-security-policy-settings
 func (p *HcaptchaProvider) CSPSources() []string {
 	return []string{
 		"https://hcaptcha.com",

internal/net/gphttp/middleware/middleware.go

@@ -34,11 +34,11 @@ type (
 	}
 
 	Middleware struct {
+		commonOptions
+
 		name      string
 		construct ImplNewFunc
 		impl      any
-
-		commonOptions
 	}
 	ByPriority []*Middleware
 
@@ -196,7 +196,12 @@ func (m *Middleware) ServeHTTP(next http.HandlerFunc, w http.ResponseWriter, r *
 
 	if exec, ok := m.impl.(ResponseModifier); ok {
 		lrm := httputils.NewLazyResponseModifier(w, needsBuffering)
-		defer lrm.FlushRelease()
+		defer func() {
+			_, err := lrm.FlushRelease()
+			if err != nil {
+				m.LogError(r).Err(err).Msg("failed to flush response")
+			}
+		}()
 		next(lrm, r)
 
 		// Skip modification if response wasn't buffered (non-HTML content)
@@ -225,7 +230,9 @@ func (m *Middleware) ServeHTTP(next http.HandlerFunc, w http.ResponseWriter, r *
 
 		// override the content length and body if changed
 		if currentResp.Body != currentBody {
-			rm.SetBody(currentResp.Body)
+			if err := rm.SetBody(currentResp.Body); err != nil {
+				m.LogError(r).Err(err).Msg("failed to set response body")
+			}
 		}
 	} else {
 		next(w, r)
@@ -239,12 +246,14 @@ func needsBuffering(header http.Header) bool {
 }
 
 func (m *Middleware) LogWarn(req *http.Request) *zerolog.Event {
+	//nolint:zerologlint
 	return log.Warn().Str("middleware", m.name).
 		Str("host", req.Host).
 		Str("path", req.URL.Path)
 }
 
 func (m *Middleware) LogError(req *http.Request) *zerolog.Event {
+	//nolint:zerologlint
 	return log.Error().Str("middleware", m.name).
 		Str("host", req.Host).
 		Str("path", req.URL.Path)