⚡ Optimize O(N^2) array traversal for variant updates in ProductStripeService

src/services/ProductStripeService.js

@@ -152,9 +152,13 @@ export class ProductStripeService {
     if (Array.isArray(updates.variants)) {
       const incomingVariants = updates.variants
       const existingVariants = Array.isArray(existingProduct.variants) ? existingProduct.variants : []
+      const existingVariantsMap = new Map()
+      for (const ev of existingVariants) {
+        if (ev.id) existingVariantsMap.set(ev.id, ev)
+      }
 
       const results = await Promise.all(incomingVariants.map(async (v) => {
-        const prior = v.id ? existingVariants.find(ev => ev.id === v.id) : undefined
+        const prior = v.id ? existingVariantsMap.get(v.id) : undefined
         const wantsCustom = !!v.hasCustomPrice && typeof v.price === 'number' && v.price > 0
 
         if (wantsCustom) {
@@ -200,9 +204,13 @@ export class ProductStripeService {
     if (Array.isArray(updates.variants2)) {
       const incomingVariants = updates.variants2
       const existingVariants = Array.isArray(existingProduct.variants2) ? existingProduct.variants2 : []
+      const existingVariantsMap = new Map()
+      for (const ev of existingVariants) {
+        if (ev.id) existingVariantsMap.set(ev.id, ev)
+      }
 
       const results = await Promise.all(incomingVariants.map(async (v) => {
-        const prior = v.id ? existingVariants.find(ev => ev.id === v.id) : undefined
+        const prior = v.id ? existingVariantsMap.get(v.id) : undefined
         const wantsCustom = !!v.hasCustomPrice && typeof v.price === 'number' && v.price > 0
 
         if (wantsCustom) {

tests/services/ProductStripeService.perf.test.js

@@ -0,0 +1,58 @@
+import { describe, it, expect } from 'vitest'
+import { ProductStripeService } from '../../src/services/ProductStripeService.js'
+
+describe('ProductStripeService Performance', () => {
+  it('measures updateProductVariants performance with many variants', async () => {
+    const mockStripeService = {
+      createPrice: async (data) => ({ id: `price_${Math.random()}` }),
+      archivePrice: async (id) => {}
+    }
+    const service = new ProductStripeService(mockStripeService)
+
+    // Generate large number of variants
+    const numVariants = 15000;
+    const existingVariants = []
+    const incomingVariants = []
+
+    for (let i = 0; i < numVariants; i++) {
+      existingVariants.push({
+        id: `var_${i}`,
+        name: `Variant ${i}`,
+        stripePriceId: `price_${i}`,
+        hasCustomPrice: true,
+        price: 10 + i
+      })
+
+      // Some with same price, some with different price
+      incomingVariants.push({
+        id: `var_${i}`,
+        name: `Variant ${i}`,
+        hasCustomPrice: true,
+        price: i % 2 === 0 ? 10 + i : 20 + i // half same, half different
+      })
+    }
+
+    const existingProduct = {
+      stripeProductId: 'prod_123',
+      stripePriceId: 'base_price',
+      currency: 'usd',
+      name: 'Test Product',
+      variants: existingVariants,
+      variants2: existingVariants // Duplicate for variants2 as well
+    }
+
+    const updates = {
+      variants: incomingVariants,
+      variants2: incomingVariants
+    }
+
+    const start = performance.now()
+    await service.updateProductVariants(existingProduct, updates, mockStripeService)
+    const end = performance.now()
+
+    const duration = end - start
+    console.log(`Update Product Variants (${numVariants} variants x 2 groups): ${duration.toFixed(2)}ms`)
+
+    expect(duration).toBeDefined()
+  })
+})