fix(store): publish initial head via heightSub

Author: Wondertan

store/store.go

@@ -108,13 +108,17 @@ func newStore[H header.Header](ds datastore.Batching, opts ...Option) (*Store[H]
 }
 
 func (s *Store[H]) Init(ctx context.Context, initial H) error {
+	if s.heightSub.Height() != 0 {
+		return fmt.Errorf("store already initialized")
+	}
 	// trust the given header as the initial head
 	err := s.flush(ctx, initial)
 	if err != nil {
 		return err
 	}
 
 	log.Infow("initialized head", "height", initial.Height(), "hash", initial.Hash())
+	s.heightSub.Pub(initial)
 	return nil
 }
 

store/store_test.go

@@ -112,3 +112,25 @@ func TestStorePendingCacheMiss(t *testing.T) {
 	_, err = store.GetRangeByHeight(ctx, 101, 151)
 	require.NoError(t, err)
 }
+
+func TestBatch_GetByHeightBeforeInit(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
+	t.Cleanup(cancel)
+
+	suite := test.NewTestSuite(t)
+
+	ds := sync.MutexWrap(datastore.NewMapDatastore())
+	store, err := NewStore[*test.DummyHeader](ds)
+	require.NoError(t, err)
+
+	err = store.Start(ctx)
+	require.NoError(t, err)
+
+	go func() {
+		_ = store.Init(ctx, suite.Head())
+	}()
+
+	h, err := store.GetByHeight(ctx, 1)
+	require.NoError(t, err)
+	require.NotNil(t, h)
+}