newEndpoint no longer references *Device, but receives individual values

extracted from the device. Makes testing easier.

usb/device.go

@@ -141,7 +141,7 @@ func (d *Device) OpenEndpoint(cfgNum, ifNum, setNum, epNum uint8) (Endpoint, err
 		return nil, fmt.Errorf("usb: unknown endpoint %02x", epNum)
 	}
 
-	end := newEndpoint(d, *ifs, *ep)
+	end := newEndpoint(d.handle, *ifs, *ep, d.ReadTimeout, d.WriteTimeout)
 
 	// Set the configuration
 	activeConf, err := libusb.getConfig(d.handle)

usb/endpoint.go

@@ -78,12 +78,12 @@ func (e *endpoint) transfer(buf []byte, timeout time.Duration) (int, error) {
 	return n, nil
 }
 
-func newEndpoint(d *Device, s InterfaceSetup, e EndpointInfo) *endpoint {
+func newEndpoint(h *libusbDevHandle, s InterfaceSetup, e EndpointInfo, rt, wt time.Duration) *endpoint {
 	return &endpoint{
 		InterfaceSetup: s,
 		EndpointInfo:   e,
-		h:              d.handle,
-		readTimeout:    d.ReadTimeout,
-		writeTimeout:   d.WriteTimeout,
+		h:              h,
+		readTimeout:    rt,
+		writeTimeout:   wt,
 	}
 }

usb/endpoint_test.go

@@ -17,6 +17,7 @@ package usb
 import (
 	"reflect"
 	"testing"
+	"time"
 )
 
 func TestEndpoint(t *testing.T) {
@@ -61,10 +62,7 @@ func TestEndpoint(t *testing.T) {
 			} {
 				lib := newFakeLibusb()
 				libusb = lib
-				ep := &endpoint{
-					InterfaceSetup: epCfg.InterfaceSetup,
-					EndpointInfo:   epCfg.EndpointInfo,
-				}
+				ep := newEndpoint(nil, epCfg.InterfaceSetup, epCfg.EndpointInfo, time.Second, time.Second)
 				op, ok := reflect.TypeOf(ep).MethodByName(epCfg.method)
 				if !ok {
 					t.Fatalf("method %s not found in endpoint struct", epCfg.method)