GetVideoFrame() nil frame buffer validation

frame.go

@@ -36,11 +36,11 @@ func GetVideoFrame(filename string, n int, frameBuffer []byte) error {
 	}
 
 	if frameBuffer == nil {
-		frameBuffer = make([]byte, frameBufferSize)
-	} else {
-		if len(frameBuffer) < frameBufferSize {
-			return errors.New("vidio: provided frame buffer size is smaller than the frame size")
-		}
+		return errors.New("vidio: provided frame buffer reference is nil")
+	}
+
+	if len(frameBuffer) < frameBufferSize {
+		return errors.New("vidio: provided frame buffer size is smaller than the frame size")
 	}
 
 	selectExpression, err := buildSelectExpression(n)

frame_test.go

@@ -30,6 +30,28 @@ func TestGetFrameShouldReturnErrorOnOutOfRangeFrame(t *testing.T) {
 	}
 }
 
+func TestGetFrameShouldReturnErrorOnNilFrameBuffer(t *testing.T) {
+	path := "test/koala.mp4"
+	var buffer []byte = nil
+
+	err := GetVideoFrame(path, 0, buffer)
+
+	if err == nil {
+		t.Error("Error was expected to not be nil")
+	}
+}
+
+func TestGetFrameShouldReturnErrorOnInvalidFrameBufferSize(t *testing.T) {
+	path := "test/koala.mp4"
+	img := image.NewRGBA(image.Rect(0, 0, 480/2, 270/2))
+
+	err := GetVideoFrame(path, 0, img.Pix)
+
+	if err == nil {
+		t.Error("Error was expected to not be nil")
+	}
+}
+
 func TestGetFrameShouldReturnCorrectFrame(t *testing.T) {
 	path := "test/koala.mp4"
 	img := image.NewRGBA(image.Rect(0, 0, 480, 270))