Some code improvements

* Rewrite empty string checks more idiomatically.
* Change strings.ToLower comparisons to strings.EqualFold.
* Rewrite switch statement with only one case as if.

transport/internet/domainsocket/config.go

@@ -12,7 +12,7 @@ const protocolName = "domainsocket"
 
 func (c *Config) GetUnixAddr() (*net.UnixAddr, error) {
 	path := c.Path
-	if len(path) == 0 {
+	if path == "" {
 		return nil, newError("empty domain socket path")
 	}
 	if c.Abstract && path[0] != '\x00' {

transport/internet/headers/http/config.go

@@ -57,7 +57,7 @@ func (v *RequestConfig) GetFullVersion() string {
 func (v *ResponseConfig) HasHeader(header string) bool {
 	cHeader := strings.ToLower(header)
 	for _, tHeader := range v.Header {
-		if strings.ToLower(tHeader.Name) == cHeader {
+		if strings.EqualFold(tHeader.Name, cHeader) {
 			return true
 		}
 	}

transport/internet/http/config.go

@@ -33,7 +33,7 @@ func (c *Config) getRandomHost() string {
 }
 
 func (c *Config) getNormalizedPath() string {
-	if len(c.Path) == 0 {
+	if c.Path == "" {
 		return "/"
 	}
 	if c.Path[0] != '/' {

transport/internet/tls/config.go

@@ -236,7 +236,7 @@ type Option func(*tls.Config)
 // WithDestination sets the server name in TLS config.
 func WithDestination(dest net.Destination) Option {
 	return func(config *tls.Config) {
-		if dest.Address.Family().IsDomain() && len(config.ServerName) == 0 {
+		if dest.Address.Family().IsDomain() && config.ServerName == "" {
 			config.ServerName = dest.Address.Domain()
 		}
 	}

transport/internet/tls/tls.go

@@ -33,7 +33,7 @@ func (c *conn) HandshakeAddress() net.Address {
 		return nil
 	}
 	state := c.Conn.ConnectionState()
-	if len(state.ServerName) == 0 {
+	if state.ServerName == "" {
 		return nil
 	}
 	return net.ParseAddress(state.ServerName)

transport/internet/websocket/config.go

@@ -13,7 +13,7 @@ const protocolName = "websocket"
 
 func (c *Config) GetNormalizedPath() string {
 	path := c.Path
-	if len(path) == 0 {
+	if path == "" {
 		return "/"
 	}
 	if path[0] != '/' {