Add test for demotion in request vote.

server_test.go

@@ -26,13 +26,14 @@ func TestServerRequestVote(t *testing.T) {
 // Ensure that a vote request is denied if it comes from an old term.
 func TestServerRequestVoteDeniedForStaleTerm(t *testing.T) {
 	server := newTestServer("1")
+	server.state = Leader
 	server.currentTerm = 2
 	resp := server.RequestVote(NewRequestVoteRequest(1, "foo", 0, 0))
 	if !(resp.Term == 2 && !resp.VoteGranted) {
 		t.Fatalf("Invalid request vote response: %v/%v", resp.Term, resp.VoteGranted)
 	}
-	if server.currentTerm != 2 {
-		t.Fatalf("Server did not update term: %v", server.currentTerm)
+	if server.currentTerm != 2 && server.state != Follower {
+		t.Fatalf("Server did not update term and demote: %v / %v", server.currentTerm, server.state)
 	}
 }