fix(explorer): return empty array for empty results (sqlite indexer) (#3469)

Author: karooolis

.changeset/thin-pianos-repair.md

@@ -0,0 +1,5 @@
+---
+"@latticexyz/explorer": patch
+---
+
+The Explorer now returns an empty array for empty results, instead of throwing an error, when using the local indexer.

packages/explorer/src/app/(explorer)/api/sqlite-indexer/route.ts

@@ -19,8 +19,18 @@ export async function POST(request: Request) {
     const result = [];
     for (const { query } of queries) {
       const data = (await db?.prepare(query).all()) as SqliteTable;
-      if (!data || !data[0]) {
-        throw new Error("No data found");
+
+      if (!data || !Array.isArray(data)) {
+        throw new Error("Invalid query result");
+      }
+
+      if (data.length === 0) {
+        result.push([]);
+        continue;
+      }
+
+      if (!data[0]) {
+        throw new Error("Invalid row data");
       }
 
       const columns = Object.keys(data[0]).map((key) => key.replaceAll("_", "").toLowerCase());