⚡ Bolt: Optimize voter diffing with O(1) Set lookups

.jules/bolt.md

@@ -9,3 +9,8 @@
 
 **Learning:** Using `on:keyup` for search input debouncing triggers unnecessary API calls on navigation keys (arrows, home, end) and misses changes from paste/cut. Svelte's reactive statements `$: debounce(value)` provide a robust, declarative way to trigger debouncing only when the value actually changes.
 **Action:** Replace `on:keyup` handlers with reactive statements for input debouncing to improve performance and correctness.
+
+## 2024-10-26 - O(N*M) Array Filtering Optimization
+
+**Learning:** Using `Array.prototype.includes()` inside an `Array.prototype.filter()` loop over large datasets creates an O(N*M) performance bottleneck. In this specific application, comparing large arrays of `owners` against `voters` synchronously blocks the main thread.
+**Action:** Always replace O(N) lookup operations like `.includes()` inside loops with an O(1) `Set.prototype.has()` check by precomputing a Set before the loop, reducing overall complexity to O(N + M).

.prettierignore

@@ -11,3 +11,6 @@ node_modules
 pnpm-lock.yaml
 package-lock.json
 yarn.lock
+.jules/
+static/
+test-results/

src/routes/api/proposals/voters/add/+server.ts

@@ -23,7 +23,9 @@ export async function GET() {
 			?.setValue()
 			.values.map((voter) => voter.addressValue().value.toString('hex')) ?? [];
 
-	const newVoters = owners.filter((owner) => !voters.includes(owner)).slice(0, 50);
+	// Optimize O(N) includes within the filter loop with an O(1) Set lookup
+	const votersSet = new Set(voters);
+	const newVoters = owners.filter((owner) => !votersSet.has(owner)).slice(0, 50);
 	if (newVoters.length === 0) return json({ newVoters }, { status: 200 });
 
 	const votingContract = await metaNamesSdk.contractRepository.getContract({

src/routes/api/proposals/voters/remove/+server.ts

@@ -25,7 +25,9 @@ export async function GET() {
 			?.setValue()
 			.values.map((voter) => voter.addressValue().value.toString('hex')) ?? [];
 
-	const votersToRemove = voters.filter((voter) => !owners.includes(voter)).slice(0, 50);
+	// Optimize O(N) includes within the filter loop with an O(1) Set lookup
+	const ownersSet = new Set(owners);
+	const votersToRemove = voters.filter((voter) => !ownersSet.has(voter)).slice(0, 50);
 	if (votersToRemove.length === 0) return json({ newVoters: votersToRemove }, { status: 200 });
 
 	const votingContract = await metaNamesSdk.contractRepository.getContract({