refactor(netxlite/mocks): group tests, fix naming inconsistencies (#485)

Part of https://github.com/ooni/probe/issues/1591

internal/netxlite/mocks/dialer.go

@@ -3,6 +3,7 @@ package mocks
 import (
 	"context"
 	"net"
+	"time"
 )
 
 // Dialer is a mockable Dialer.
@@ -20,3 +21,57 @@ func (d *Dialer) DialContext(ctx context.Context, network, address string) (net.
 func (d *Dialer) CloseIdleConnections() {
 	d.MockCloseIdleConnections()
 }
+
+// Conn is a mockable net.Conn.
+type Conn struct {
+	MockRead             func(b []byte) (int, error)
+	MockWrite            func(b []byte) (int, error)
+	MockClose            func() error
+	MockLocalAddr        func() net.Addr
+	MockRemoteAddr       func() net.Addr
+	MockSetDeadline      func(t time.Time) error
+	MockSetReadDeadline  func(t time.Time) error
+	MockSetWriteDeadline func(t time.Time) error
+}
+
+// Read calls MockRead.
+func (c *Conn) Read(b []byte) (int, error) {
+	return c.MockRead(b)
+}
+
+// Write calls MockWrite.
+func (c *Conn) Write(b []byte) (int, error) {
+	return c.MockWrite(b)
+}
+
+// Close calls MockClose.
+func (c *Conn) Close() error {
+	return c.MockClose()
+}
+
+// LocalAddr calls MockLocalAddr.
+func (c *Conn) LocalAddr() net.Addr {
+	return c.MockLocalAddr()
+}
+
+// RemoteAddr calls MockRemoteAddr.
+func (c *Conn) RemoteAddr() net.Addr {
+	return c.MockRemoteAddr()
+}
+
+// SetDeadline calls MockSetDeadline.
+func (c *Conn) SetDeadline(t time.Time) error {
+	return c.MockSetDeadline(t)
+}
+
+// SetReadDeadline calls MockSetReadDeadline.
+func (c *Conn) SetReadDeadline(t time.Time) error {
+	return c.MockSetReadDeadline(t)
+}
+
+// SetWriteDeadline calls MockSetWriteDeadline.
+func (c *Conn) SetWriteDeadline(t time.Time) error {
+	return c.MockSetWriteDeadline(t)
+}
+
+var _ net.Conn = &Conn{}