Fix lint errors

wrappers/conn.go

@@ -9,6 +9,9 @@ import (
 	"github.com/9seconds/mtg/stats"
 )
 
+// ConnPurpose is intented to be identifier of connection purpose. We
+// sometimes want to treat client/telegram connection differently (for
+// logging for example).
 type ConnPurpose uint8
 
 func (c ConnPurpose) String() string {
@@ -22,6 +25,7 @@ func (c ConnPurpose) String() string {
 	return ""
 }
 
+// ConnPurpose* define different connection types.
 const (
 	ConnPurposeClient = iota
 	ConnPurposeTelegram
@@ -32,6 +36,8 @@ const (
 	connTimeoutWrite = 5 * time.Minute
 )
 
+// Conn is a basic wrapper for net.Conn providing the most low-level
+// logic and management as possible.
 type Conn struct {
 	connID string
 	conn   net.Conn
@@ -42,7 +48,7 @@ type Conn struct {
 }
 
 func (c *Conn) Write(p []byte) (int, error) {
-	c.conn.SetWriteDeadline(time.Now().Add(connTimeoutWrite))
+	c.conn.SetWriteDeadline(time.Now().Add(connTimeoutWrite)) // nolint: errcheck
 	n, err := c.conn.Write(p)
 
 	c.logger.Debugw("Write to stream", "bytes", n, "error", err)
@@ -52,7 +58,7 @@ func (c *Conn) Write(p []byte) (int, error) {
 }
 
 func (c *Conn) Read(p []byte) (int, error) {
-	c.conn.SetReadDeadline(time.Now().Add(connTimeoutRead))
+	c.conn.SetReadDeadline(time.Now().Add(connTimeoutRead)) // nolint: errcheck
 	n, err := c.conn.Read(p)
 
 	c.logger.Debugw("Read from stream", "bytes", n, "error", err)
@@ -61,11 +67,18 @@ func (c *Conn) Read(p []byte) (int, error) {
 	return n, err
 }
 
+// Close closes underlying net.Conn instance.
 func (c *Conn) Close() error {
-	defer c.logger.Debugw("Closed connection")
+	defer c.logger.Debugw("Close connection")
 	return c.conn.Close()
 }
 
+// Logger returns an instance of the logger for this wrapper.
+func (c *Conn) Logger() *zap.SugaredLogger {
+	return c.logger
+}
+
+// LocalAddr returns local address of the underlying net.Conn.
 func (c *Conn) LocalAddr() *net.TCPAddr {
 	addr := c.conn.LocalAddr().(*net.TCPAddr)
 	newAddr := *addr
@@ -81,14 +94,12 @@ func (c *Conn) LocalAddr() *net.TCPAddr {
 	return &newAddr
 }
 
+// RemoteAddr returns remote address of the underlying net.Conn.
 func (c *Conn) RemoteAddr() *net.TCPAddr {
 	return c.conn.RemoteAddr().(*net.TCPAddr)
 }
 
-func (c *Conn) Logger() *zap.SugaredLogger {
-	return c.logger
-}
-
+// NewConn initializes Conn wrapper for net.Conn.
 func NewConn(conn net.Conn, connID string, purpose ConnPurpose, publicIPv4, publicIPv6 net.IP) StreamReadWriteCloser {
 	logger := zap.S().With(
 		"connection_id", connID,