Added test to detect correct behaviour in Close and Read ops

serial_linux_test.go

@@ -0,0 +1,41 @@
+//
+// Copyright 2014-2020 Cristian Maglie. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+//
+// Testing code idea and fix thanks to @angri
+// https://github.com/bugst/go-serial/pull/42
+//
+
+package serial
+
+import (
+	"context"
+	"os/exec"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSerialReadAndCloseConcurrency(t *testing.T) {
+
+	// Run this test with race detector to actually test that
+	// the correct multitasking behaviour is happening.
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	cmd := exec.CommandContext(ctx, "socat", "STDIO", "pty,link=/tmp/faketty")
+	require.NoError(t, cmd.Start())
+	go cmd.Wait()
+	// let our fake serial port node to appear
+	time.Sleep(time.Millisecond * 100)
+
+	port, err := Open("/tmp/faketty", &Mode{})
+	require.NoError(t, err)
+	buf := make([]byte, 100)
+	go port.Read(buf)
+	// let port.Read to start
+	time.Sleep(time.Millisecond * 1)
+	port.Close()
+}