slight refactor of delete-by-id implementation

pages/chat/facts.ts

@@ -25,12 +25,11 @@ export const facts = router({
         },
     )
     .mutation(async ({ input: { factId } }) => {
-      const deletedFact = db.data.facts.find((fact) => fact.id === factId);
-      if (!deletedFact) throw new Error("Fact not found");
-      db.data.facts.splice(
-        db.data.facts.findIndex((fact) => fact.id === factId),
-        1,
+      const deletedFactId = db.data.facts.findIndex(
+        (fact) => fact.id === factId,
       );
+      if (deletedFactId === -1) throw new Error("Fact not found");
+      db.data.facts.splice(deletedFactId, 1);
       db.write();
       return { ok: true };
     }),