Add unit test to make sure historical queries only serve from SS

sei-cosmos/storev2/rootmulti/store.go

@@ -242,7 +242,6 @@ func (rs *Store) CacheMultiStoreWithVersion(version int64) (types.CacheMultiStor
 			stores[k] = store
 		}
 	}
-	// TODO: May need to add historical SC store as well for nodes that doesn't enable ss but still need historical queries
 
 	// add SS stores for historical queries
 	if rs.ssStore != nil {

sei-cosmos/storev2/rootmulti/store_test.go

@@ -6,6 +6,7 @@ import (
 	"time"
 
 	"github.com/cosmos/cosmos-sdk/store/types"
+	"github.com/cosmos/cosmos-sdk/storev2/state"
 	"github.com/sei-protocol/sei-db/config"
 	"github.com/stretchr/testify/require"
 	abci "github.com/tendermint/tendermint/abci/types"
@@ -93,3 +94,102 @@ func TestSCSS_WriteAndHistoricalRead(t *testing.T) {
 	require.EqualValues(t, 0, resp.Code)
 	require.Equal(t, valV1, resp.Value)
 }
+
+// TestCacheMultiStoreWithVersion_OnlyUsesSSStores verifies that CacheMultiStoreWithVersion
+// never adds SC stores and only adds SS stores for historical queries, ensuring that
+// historical queries only serve from SS stores.
+func TestCacheMultiStoreWithVersion_OnlyUsesSSStores(t *testing.T) {
+	// Enable both SC and SS with default configs
+	home := t.TempDir()
+	scCfg := config.DefaultStateCommitConfig()
+	scCfg.Enable = true
+	ssCfg := config.DefaultStateStoreConfig()
+	ssCfg.Enable = true
+
+	store := NewStore(home, log.NewNopLogger(), scCfg, ssCfg, false)
+	defer func() { _ = store.Close() }()
+
+	// Mount IAVL stores and transient/mem stores
+	iavlKey1 := types.NewKVStoreKey("iavl_store1")
+	iavlKey2 := types.NewKVStoreKey("iavl_store2")
+	transientKey := types.NewTransientStoreKey("transient_store")
+	memKey := types.NewMemoryStoreKey("mem_store")
+
+	store.MountStoreWithDB(iavlKey1, types.StoreTypeIAVL, nil)
+	store.MountStoreWithDB(iavlKey2, types.StoreTypeIAVL, nil)
+	store.MountStoreWithDB(transientKey, types.StoreTypeTransient, nil)
+	store.MountStoreWithDB(memKey, types.StoreTypeMemory, nil)
+	require.NoError(t, store.LoadLatestVersion())
+
+	// Write data to IAVL stores and commit
+	iavl1KV := store.GetStoreByName("iavl_store1").(types.KVStore)
+	iavl2KV := store.GetStoreByName("iavl_store2").(types.KVStore)
+	iavl1KV.Set([]byte("k1"), []byte("v1"))
+	iavl2KV.Set([]byte("k2"), []byte("v2"))
+	c1 := store.Commit(true)
+	require.Equal(t, int64(1), c1.Version)
+
+	// Write more data and commit again
+	iavl1KV = store.GetStoreByName("iavl_store1").(types.KVStore)
+	iavl2KV = store.GetStoreByName("iavl_store2").(types.KVStore)
+	iavl1KV.Set([]byte("k1"), []byte("v1_updated"))
+	iavl2KV.Set([]byte("k2"), []byte("v2_updated"))
+	c2 := store.Commit(true)
+	require.Equal(t, int64(2), c2.Version)
+
+	// Wait for SS to asynchronously catch up to v2
+	waitUntilSSVersion(t, store, c2.Version)
+
+	// Test: Call CacheMultiStoreWithVersion for historical version v1
+	cmsV1, err := store.CacheMultiStoreWithVersion(c1.Version)
+	require.NoError(t, err)
+
+	// Verify IAVL stores are SS stores (StoreTypeSSStore), not SC stores (StoreTypeIAVL)
+	iavl1Store := cmsV1.GetKVStore(iavlKey1)
+	iavl2Store := cmsV1.GetKVStore(iavlKey2)
+	require.NotNil(t, iavl1Store)
+	require.NotNil(t, iavl2Store)
+
+	// The stores are wrapped in cachekv, but GetStoreType() delegates to the underlying store
+	require.Equal(t, types.StoreType(state.StoreTypeSSStore), iavl1Store.GetStoreType(),
+		"IAVL store should be SS store (StoreTypeSSStore), not SC store (StoreTypeIAVL)")
+	require.Equal(t, types.StoreType(state.StoreTypeSSStore), iavl2Store.GetStoreType(),
+		"IAVL store should be SS store (StoreTypeSSStore), not SC store (StoreTypeIAVL)")
+
+	// Verify transient and mem stores are still present with their original types
+	transientStore := cmsV1.GetKVStore(transientKey)
+	memStore := cmsV1.GetKVStore(memKey)
+	require.NotNil(t, transientStore)
+	require.NotNil(t, memStore)
+	require.Equal(t, types.StoreTypeTransient, transientStore.GetStoreType(),
+		"Transient store should maintain its type")
+	require.Equal(t, types.StoreTypeMemory, memStore.GetStoreType(),
+		"Memory store should maintain its type")
+
+	// Verify the stores serve historical data from SS (v1 values, not v2)
+	require.Equal(t, []byte("v1"), iavl1Store.Get([]byte("k1")),
+		"Should serve v1 data from SS store")
+	require.Equal(t, []byte("v2"), iavl2Store.Get([]byte("k2")),
+		"Should serve v1 data from SS store")
+
+	// Verify that SC stores (StoreTypeIAVL) are NOT present in the returned cache multi store
+	// by checking that all IAVL stores have StoreTypeSSStore, not StoreTypeIAVL
+	require.NotEqual(t, types.StoreTypeIAVL, iavl1Store.GetStoreType(),
+		"IAVL store should NOT be SC store (StoreTypeIAVL)")
+	require.NotEqual(t, types.StoreTypeIAVL, iavl2Store.GetStoreType(),
+		"IAVL store should NOT be SC store (StoreTypeIAVL)")
+
+	// Test with latest version as well - should still use SS stores if available
+	cmsV2, err := store.CacheMultiStoreWithVersion(c2.Version)
+	require.NoError(t, err)
+	iavl1StoreV2 := cmsV2.GetKVStore(iavlKey1)
+	iavl2StoreV2 := cmsV2.GetKVStore(iavlKey2)
+	require.Equal(t, types.StoreType(state.StoreTypeSSStore), iavl1StoreV2.GetStoreType(),
+		"Latest version IAVL store should also be SS store")
+	require.Equal(t, types.StoreType(state.StoreTypeSSStore), iavl2StoreV2.GetStoreType(),
+		"Latest version IAVL store should also be SS store")
+	require.Equal(t, []byte("v1_updated"), iavl1StoreV2.Get([]byte("k1")),
+		"Should serve v2 data from SS store")
+	require.Equal(t, []byte("v2_updated"), iavl2StoreV2.Get([]byte("k2")),
+		"Should serve v2 data from SS store")
+}