Add comment on locker_test.go regarding testing the session KeepAlive

etcd3locker/locker.go

@@ -42,7 +42,7 @@ func NewWithPrefix(client *etcd3.Client, prefix string) (*etcd3Locker, error) {
 }
 
 // This method may be used if we want control over both prefix/session TTLs. This is used for testing in particular.
-func NewWithLockerOptions(client *etcd3.Client, opts *LockerOptions) (*etcd3Locker, error) {
+func NewWithLockerOptions(client *etcd3.Client, opts LockerOptions) (*etcd3Locker, error) {
 	locksMap := map[string]*etcd3Lock{}
 	return &etcd3Locker{Client: client, prefix: opts.Prefix(), sessionTimeout: opts.Timeout(), locks: locksMap, mutex: sync.Mutex{}}, nil
 }

etcd3locker/locker_options.go

@@ -14,15 +14,15 @@ type LockerOptions struct {
 	prefix         string
 }
 
-func DefaultLockerOptions() *LockerOptions {
-	return &LockerOptions{
+func DefaultLockerOptions() LockerOptions {
+	return LockerOptions{
 		timeoutSeconds: 60,
 		prefix:         "/tusd",
 	}
 }
 
-func NewLockerOptions(timeout int, prefix string) *LockerOptions {
-	return &LockerOptions{
+func NewLockerOptions(timeout int, prefix string) LockerOptions {
+	return LockerOptions{
 		timeoutSeconds: timeout,
 		prefix:         prefix,
 	}

etcd3locker/locker_test.go

@@ -43,6 +43,8 @@ func TestEtcd3Locker(t *testing.T) {
 	a.NoError(locker.LockUpload("one"))
 	a.Equal(tusd.ErrFileLocked, locker.LockUpload("one"))
 	time.Sleep(5 * time.Second)
+	// test that we can't take over the upload via a different etcd3 session
+	// while an upload is already taking place; testing etcd3 session KeepAlive
 	a.Equal(tusd.ErrFileLocked, locker.LockUpload("one"))
 	a.NoError(locker.UnlockUpload("one"))
 	a.Equal(ErrLockNotHeld, locker.UnlockUpload("one"))