control/controlclient: unexport Status.state, add test-only accessor

Updates #cleanup
Updates #1909

Change-Id: I38dcde6fa0de0f58ede4529992cee2e36de33dd6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

control/controlclient/auto.go

@@ -666,8 +666,8 @@ func (c *Auto) sendStatus(who string, err error, url string, nm *netmap.NetworkM
 		URL:            url,
 		Persist:        p,
 		NetMap:         nm,
-		State:          state,
 		Err:            err,
+		state:          state,
 	}
 	c.observer.SetControlClientStatus(new)
 

control/controlclient/controlclient_test.go

@@ -21,7 +21,7 @@ func fieldsOf(t reflect.Type) (fields []string) {
 
 func TestStatusEqual(t *testing.T) {
 	// Verify that the Equal method stays in sync with reality
-	equalHandles := []string{"LoginFinished", "LogoutFinished", "Err", "URL", "NetMap", "State", "Persist"}
+	equalHandles := []string{"LoginFinished", "LogoutFinished", "Err", "URL", "NetMap", "Persist", "state"}
 	if have := fieldsOf(reflect.TypeOf(Status{})); !reflect.DeepEqual(have, equalHandles) {
 		t.Errorf("Status.Equal check might be out of sync\nfields: %q\nhandled: %q\n",
 			have, equalHandles)
@@ -52,13 +52,13 @@ func TestStatusEqual(t *testing.T) {
 			true,
 		},
 		{
-			&Status{State: StateNew},
-			&Status{State: StateNew},
+			&Status{state: StateNew},
+			&Status{state: StateNew},
 			true,
 		},
 		{
-			&Status{State: StateNew},
-			&Status{State: StateAuthenticated},
+			&Status{state: StateNew},
+			&Status{state: StateAuthenticated},
 			false,
 		},
 		{

control/controlclient/status.go

@@ -69,14 +69,18 @@ type Status struct {
 	URL            string             // interactive URL to visit to finish logging in
 	NetMap         *netmap.NetworkMap // server-pushed configuration
 
-	// The internal state should not be exposed outside this
+	Persist *persist.PersistView // locally persisted configuration
+
+	// state is the internal state. It should not be exposed outside this
 	// package, but we have some automated tests elsewhere that need to
-	// use them. Please don't use these fields.
+	// use it via the StateForTest accessor.
 	// TODO(apenwarr): Unexport or remove these.
-	State   State
-	Persist *persist.PersistView // locally persisted configuration
+	state State
 }
 
+// StateForTest returns the internal state of s for tests only.
+func (s *Status) StateForTest() State { return s.state }
+
 // Equal reports whether s and s2 are equal.
 func (s *Status) Equal(s2 *Status) bool {
 	if s == nil && s2 == nil {
@@ -89,7 +93,7 @@ func (s *Status) Equal(s2 *Status) bool {
 		s.URL == s2.URL &&
 		reflect.DeepEqual(s.Persist, s2.Persist) &&
 		reflect.DeepEqual(s.NetMap, s2.NetMap) &&
-		s.State == s2.State
+		s.state == s2.state
 }
 
 func (s Status) String() string {
@@ -97,5 +101,5 @@ func (s Status) String() string {
 	if err != nil {
 		panic(err)
 	}
-	return s.State.String() + " " + string(b)
+	return s.state.String() + " " + string(b)
 }