lobby tested and kinda ok

src/state/fsm/lobby/lobby_test.go

@@ -7,9 +7,41 @@ import (
 )
 
 func TestOpen(t *testing.T) {
-	l, err := lobby.Open(lib.NewTestCtx(t), "id")
+	ctx := lib.NewTestCtx(t)
+
+	l, err := lobby.Open(ctx, "id")
 	if err != nil {
 		t.Fatal(err)
 	}
 	t.Logf("%+v", l)
+
+	if len(l.Players) != 0 {
+		t.Errorf("new lobby has players: %+v", l.Players)
+	}
+
+	if err := l.Join(ctx, 1); err != nil {
+		t.Fatal("failed to join:", err)
+	} else if len(l.Players) != 1 {
+		t.Errorf("wrong number of players after first join: %+v", l.Players)
+	}
+
+	if err := l.Leave(ctx, 1); err != nil {
+		t.Fatal("failed to join:", err)
+	} else if len(l.Players) != 0 {
+		t.Errorf("wrong number of players after only leaves: %+v", l.Players)
+	}
+
+	if err := l.Join(ctx, 1); err != nil {
+		t.Fatal("failed to join:", err)
+	} else if err := l.Join(ctx, 1); err != nil {
+		t.Fatal("failed to join redundant:", err)
+	} else if len(l.Players) != 1 {
+		t.Errorf("redundant join yielded wrong players: %+v", l.Players)
+	}
+
+	if err := l.Join(ctx, 2); err != nil {
+		t.Fatal("failed to second join:", err)
+	} else if len(l.Players) != 2 {
+		t.Errorf("second join yielded wrong players: %+v", l.Players)
+	}
 }