feat: tests for the chain indexer (#12521)

* ddl tests

* tests for the chain indexer

* finish unit tests for chain indexer

* fix formatting

chain/index/api.go

@@ -223,7 +223,8 @@ func (si *SqliteIndexer) verifyIndexedData(ctx context.Context, ts *types.TipSet
 		return xerrors.Errorf("failed to get next tipset for height %d: %w", ts.Height(), err)
 	}
 
-	// if non-reverted events exist which means that tipset `ts` has been executed, there should be 0 reverted events in the DB
+	// given that `ts` is on the canonical chain and `executionTs` is the next tipset in the chain
+	// `ts` can not have reverted events
 	var hasRevertedEventsInTipset bool
 	err = si.stmts.hasRevertedEventsInTipsetStmt.QueryRowContext(ctx, tsKeyCid.Bytes()).Scan(&hasRevertedEventsInTipset)
 	if err != nil {
@@ -233,7 +234,7 @@ func (si *SqliteIndexer) verifyIndexedData(ctx context.Context, ts *types.TipSet
 		return xerrors.Errorf("index corruption: reverted events found for an executed tipset %s at height %d", tsKeyCid, ts.Height())
 	}
 
-	executedMsgs, err := si.loadExecutedMessages(ctx, ts, executionTs)
+	executedMsgs, err := si.eventLoaderFunc(ctx, si.cs, ts, executionTs)
 	if err != nil {
 		return xerrors.Errorf("failed to load executed messages for height %d: %w", ts.Height(), err)
 	}