microbit: refactoring and increase test coverage for IOPinDriver

Signed-off-by: deadprogram <ron@hybridgroup.com>

platforms/microbit/io_pin_driver.go

@@ -3,6 +3,7 @@ package microbit
 import (
 	"bytes"
 	"encoding/binary"
+	"errors"
 	"strconv"
 
 	"gobot.io/x/gobot"
@@ -154,7 +155,7 @@ func (b *IOPinDriver) Finalize() (err error) {
 
 // DigitalRead reads from a pin
 func (b *IOPinDriver) DigitalRead(pin string) (val int, err error) {
-	p, err := strconv.Atoi(pin)
+	p, err := validatedPin(pin)
 	if err != nil {
 		return
 	}
@@ -168,7 +169,7 @@ func (b *IOPinDriver) DigitalRead(pin string) (val int, err error) {
 
 // DigitalWrite writes to a pin
 func (b *IOPinDriver) DigitalWrite(pin string, level byte) (err error) {
-	p, err := strconv.Atoi(pin)
+	p, err := validatedPin(pin)
 	if err != nil {
 		return
 	}
@@ -181,7 +182,7 @@ func (b *IOPinDriver) DigitalWrite(pin string, level byte) (err error) {
 
 // AnalogRead reads from a pin
 func (b *IOPinDriver) AnalogRead(pin string) (val int, err error) {
-	p, err := strconv.Atoi(pin)
+	p, err := validatedPin(pin)
 	if err != nil {
 		return
 	}
@@ -217,6 +218,19 @@ func (b *IOPinDriver) ensureOutput(pin int) {
 	}
 }
 
+func validatedPin(pin string) (int, error) {
+	i, err := strconv.Atoi(pin)
+	if err != nil {
+		return 0, err
+	}
+
+	if i < 0 || i > 2 {
+		return 0, errors.New("Invalid pin.")
+	}
+
+	return i, nil
+}
+
 // via http://stackoverflow.com/questions/23192262/how-would-you-set-and-clear-a-single-bit-in-go
 
 // Sets the bit at pos in the integer n.

platforms/microbit/io_pin_driver_test.go

@@ -1,6 +1,7 @@
 package microbit
 
 import (
+	"errors"
 	"strings"
 	"testing"
 
@@ -53,6 +54,17 @@ func TestIOPinDriverDigitalRead(t *testing.T) {
 	gobottest.Assert(t, val, 0)
 }
 
+func TestIOPinDriverDigitalReadInvalidPin(t *testing.T) {
+	a := NewBleTestAdaptor()
+	d := NewIOPinDriver(a)
+
+	_, err := d.DigitalRead("A3")
+	gobottest.Refute(t, err, nil)
+
+	_, err = d.DigitalRead("6")
+	gobottest.Assert(t, err, errors.New("Invalid pin."))
+}
+
 func TestIOPinDriverDigitalWrite(t *testing.T) {
 	a := NewBleTestAdaptor()
 	d := NewIOPinDriver(a)
@@ -61,6 +73,14 @@ func TestIOPinDriverDigitalWrite(t *testing.T) {
 	gobottest.Assert(t, d.DigitalWrite("0", 1), nil)
 }
 
+func TestIOPinDriverDigitalWriteInvalidPin(t *testing.T) {
+	a := NewBleTestAdaptor()
+	d := NewIOPinDriver(a)
+
+	gobottest.Refute(t, d.DigitalWrite("A3", 1), nil)
+	gobottest.Assert(t, d.DigitalWrite("6", 1), errors.New("Invalid pin."))
+}
+
 func TestIOPinDriverAnalogRead(t *testing.T) {
 	a := NewBleTestAdaptor()
 	d := NewIOPinDriver(a)
@@ -75,6 +95,17 @@ func TestIOPinDriverAnalogRead(t *testing.T) {
 	gobottest.Assert(t, val, 128)
 }
 
+func TestIOPinDriverAnalogReadInvalidPin(t *testing.T) {
+	a := NewBleTestAdaptor()
+	d := NewIOPinDriver(a)
+
+	_, err := d.AnalogRead("A3")
+	gobottest.Refute(t, err, nil)
+
+	_, err = d.AnalogRead("6")
+	gobottest.Assert(t, err, errors.New("Invalid pin."))
+}
+
 func TestIOPinDriverDigitalAnalogRead(t *testing.T) {
 	a := NewBleTestAdaptor()
 	d := NewIOPinDriver(a)
@@ -101,3 +132,16 @@ func TestIOPinDriverDigitalWriteAnalogRead(t *testing.T) {
 	val, _ := d.AnalogRead("1")
 	gobottest.Assert(t, val, 128)
 }
+
+func TestIOPinDriverAnalogReadDigitalWrite(t *testing.T) {
+	a := NewBleTestAdaptor()
+	d := NewIOPinDriver(a)
+	a.TestReadCharacteristic(func(cUUID string) ([]byte, error) {
+		return []byte{0, 0, 1, 128, 2, 1}, nil
+	})
+
+	val, _ := d.AnalogRead("1")
+	gobottest.Assert(t, val, 128)
+
+	gobottest.Assert(t, d.DigitalWrite("1", 0), nil)
+}