diff --git a/doc_test.go b/doc_test.go
new file mode 100644
index 0000000..b9a4486
--- /dev/null
+++ b/doc_test.go
@@ -0,0 +1,335 @@
+package pty
+
+import (
+	"bytes"
+	"io"
+	"testing"
+)
+
+// Will fill p from reader r
+func readBytes(r io.Reader, p []byte) error {
+	bytesRead := 0
+	for bytesRead < len(p) {
+		n, err := r.Read(p[bytesRead:])
+		if err != nil {
+			return err
+		}
+		bytesRead = bytesRead + n
+	}
+	return nil
+}
+
+func TestOpen(t *testing.T) {
+	t.Parallel()
+
+	pty, tty, err := Open()
+	if err != nil {
+		t.Errorf("Unexpected error from Open: %s", err)
+	}
+
+	err = tty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from tty Close: %s", err)
+	}
+
+	err = pty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from pty Close: %s", err)
+	}
+}
+
+func TestName(t *testing.T) {
+	t.Parallel()
+
+	pty, tty, err := Open()
+	if err != nil {
+		t.Errorf("Unexpected error from Open: %s", err)
+	}
+
+	// Check name isn't empty. There's variation on what exactly the OS calls these files.
+	if pty.Name() == "" {
+		t.Error("pty name was empty")
+	}
+	if tty.Name() == "" {
+		t.Error("tty name was empty")
+	}
+
+	err = tty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from tty Close: %s", err)
+	}
+
+	err = pty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from pty Close: %s", err)
+	}
+}
+
+func TestGetsize(t *testing.T) {
+	t.Parallel()
+
+	pty, tty, err := Open()
+	if err != nil {
+		t.Errorf("Unexpected error from Open: %s", err)
+	}
+
+	prows, pcols, err := Getsize(pty)
+	if err != nil {
+		t.Errorf("Unexpected error from Getsize: %s", err)
+	}
+
+	trows, tcols, err := Getsize(tty)
+	if err != nil {
+		t.Errorf("Unexpected error from Getsize: %s", err)
+	}
+
+	if prows != trows {
+		t.Errorf("pty rows != tty rows: %d != %d", prows, trows)
+	}
+	if prows != trows {
+		t.Errorf("pty cols != tty cols: %d != %d", pcols, tcols)
+	}
+
+	err = tty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from tty Close: %s", err)
+	}
+
+	err = pty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from pty Close: %s", err)
+	}
+}
+
+func TestGetsizefull(t *testing.T) {
+	t.Parallel()
+
+	pty, tty, err := Open()
+	if err != nil {
+		t.Errorf("Unexpected error from Open: %s", err)
+	}
+
+	psize, err := GetsizeFull(pty)
+	if err != nil {
+		t.Errorf("Unexpected error from GetsizeFull: %s", err)
+	}
+
+	tsize, err := GetsizeFull(tty)
+	if err != nil {
+		t.Errorf("Unexpected error from GetsizeFull: %s", err)
+	}
+
+	if psize.X != tsize.X {
+		t.Errorf("pty x != tty x: %d != %d", psize.X, tsize.X)
+	}
+	if psize.Y != tsize.Y {
+		t.Errorf("pty y != tty y: %d != %d", psize.Y, tsize.Y)
+	}
+	if psize.Rows != tsize.Rows {
+		t.Errorf("pty rows != tty rows: %d != %d", psize.Rows, tsize.Rows)
+	}
+	if psize.Cols != tsize.Cols {
+		t.Errorf("pty cols != tty cols: %d != %d", psize.Cols, tsize.Cols)
+	}
+
+	err = tty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from tty Close: %s", err)
+	}
+
+	err = pty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from pty Close: %s", err)
+	}
+}
+
+func TestSetsize(t *testing.T) {
+	t.Parallel()
+
+	pty, tty, err := Open()
+	if err != nil {
+		t.Errorf("Unexpected error from Open: %s", err)
+	}
+
+	psize, err := GetsizeFull(pty)
+	if err != nil {
+		t.Errorf("Unexpected error from GetsizeFull: %s", err)
+	}
+
+	psize.X = psize.X + 1
+	psize.Y = psize.Y + 1
+	psize.Rows = psize.Rows + 1
+	psize.Cols = psize.Cols + 1
+
+	err = Setsize(tty, psize)
+	if err != nil {
+		t.Errorf("Unexpected error from Setsize: %s", err)
+	}
+
+	tsize, err := GetsizeFull(tty)
+	if err != nil {
+		t.Errorf("Unexpected error from GetsizeFull: %s", err)
+	}
+
+	if psize.X != tsize.X {
+		t.Errorf("pty x != tty x: %d != %d", psize.X, tsize.X)
+	}
+	if psize.Y != tsize.Y {
+		t.Errorf("pty y != tty y: %d != %d", psize.Y, tsize.Y)
+	}
+	if psize.Rows != tsize.Rows {
+		t.Errorf("pty rows != tty rows: %d != %d", psize.Rows, tsize.Rows)
+	}
+	if psize.Cols != tsize.Cols {
+		t.Errorf("pty cols != tty cols: %d != %d", psize.Cols, tsize.Cols)
+	}
+
+	err = tty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from tty Close: %s", err)
+	}
+
+	err = pty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from pty Close: %s", err)
+	}
+}
+
+func TestReadWriteText(t *testing.T) {
+	t.Parallel()
+
+	pty, tty, err := Open()
+	if err != nil {
+		t.Errorf("Unexpected error from Open: %s", err)
+	}
+
+	// Write to tty, read from pty
+	text := []byte("ping")
+	n, err := tty.Write(text)
+	if err != nil {
+		t.Errorf("Unexpected error from Write: %s", err)
+	}
+	if n != len(text) {
+		t.Errorf("Unexpected count returned from Write, got %d expected %d", n, len(text))
+	}
+
+	buffer := make([]byte, 4)
+	err = readBytes(pty, buffer)
+	if err != nil {
+		t.Errorf("Unexpected error from readBytes: %s", err)
+	}
+	if !bytes.Equal(text, buffer) {
+		t.Errorf("Unexpected result returned from Read, got %v expected %v", buffer, text)
+	}
+
+	// Write to pty, read from tty.
+	// We need to send a \n otherwise this will block in the terminal driver.
+	text = []byte("pong\n")
+	n, err = pty.Write(text)
+	if err != nil {
+		t.Errorf("Unexpected error from Write: %s", err)
+	}
+	if n != len(text) {
+		t.Errorf("Unexpected count returned from Write, got %d expected %d", n, len(text))
+	}
+
+	buffer = make([]byte, 5)
+	err = readBytes(tty, buffer)
+	if err != nil {
+		t.Errorf("Unexpected error from readBytes: %s", err)
+	}
+	expect := []byte("pong\n")
+	if !bytes.Equal(expect, buffer) {
+		t.Errorf("Unexpected result returned from Read, got %v expected %v", buffer, expect)
+	}
+
+	// Read the echo back from pty
+	buffer = make([]byte, 5)
+	err = readBytes(pty, buffer)
+	if err != nil {
+		t.Errorf("Unexpected error from readBytes: %s", err)
+	}
+	expect = []byte("pong\r")
+	if !bytes.Equal(expect, buffer) {
+		t.Errorf("Unexpected result returned from Read, got %v expected %v", buffer, expect)
+	}
+
+	err = tty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from tty Close: %s", err)
+	}
+
+	err = pty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from pty Close: %s", err)
+	}
+}
+
+func TestReadWriteControls(t *testing.T) {
+	t.Parallel()
+
+	pty, tty, err := Open()
+	if err != nil {
+		t.Errorf("Unexpected error from Open: %s", err)
+	}
+
+	// Write the start of a line to pty
+	text := []byte("pind")
+	n, err := pty.Write(text)
+	if err != nil {
+		t.Errorf("Unexpected error from Write: %s", err)
+	}
+	if n != len(text) {
+		t.Errorf("Unexpected count returned from Write, got %d expected %d", n, len(text))
+	}
+
+	// Backspace that last char
+	n, err = pty.Write([]byte("\b"))
+	if err != nil {
+		t.Errorf("Unexpected error from Write: %s", err)
+	}
+	if n != 1 {
+		t.Errorf("Unexpected count returned from Write, got %d expected %d", n, 1)
+	}
+
+	// Write the correct char and a CR
+	n, err = pty.Write([]byte("g\n"))
+	if err != nil {
+		t.Errorf("Unexpected error from Write: %s", err)
+	}
+	if n != 2 {
+		t.Errorf("Unexpected count returned from Write, got %d expected %d", n, 2)
+	}
+
+	// Read the line
+	buffer := make([]byte, 7)
+	err = readBytes(tty, buffer)
+	if err != nil {
+		t.Errorf("Unexpected error from readBytes: %s", err)
+	}
+	expect := []byte("pind\bg\n")
+	if !bytes.Equal(expect, buffer) {
+		t.Errorf("Unexpected result returned from Read, got %v expected %v", buffer, expect)
+	}
+
+	// Read the echo back from pty
+	buffer = make([]byte, 7)
+	err = readBytes(pty, buffer)
+	if err != nil {
+		t.Errorf("Unexpected error from readBytes: %s", err)
+	}
+	expect = []byte("pind^Hg")
+	if !bytes.Equal(expect, buffer) {
+		t.Errorf("Unexpected result returned from Read, got %v expected %v", buffer, expect)
+	}
+
+	err = tty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from tty Close: %s", err)
+	}
+
+	err = pty.Close()
+	if err != nil {
+		t.Errorf("Unexpected error from pty Close: %s", err)
+	}
+}