feat(ci): enable unlighthouse performance audits for vercel (#2882)

* feat(ci): enable unlighthouse performance audits for vercel

Re-enable the performance category in Unlighthouse with mitigations for
hardware throttling: maxConcurrency=1 and samples=5 (median smoothing
absorbs cold start outliers across all discovered pages without needing
an explicit warm-up step). Rename artifacts with a "vercel" label for
future cross-platform comparison.

CATALYST-1768

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

* chore: revert samples to 3

* chore: add concurrency to speed tests

* fix: target specific PLP and PDP pages to prevent wasted runtime

* fix: change PLP category to bath

* fix: expand report

* chore: test concurrency and all routes

* fix: fixed paths, multiple samples, with concurrency

* fix: run all pages, concurrency enabled, 1 sample size

* fix: add sample size of 3

* feat: add dynamic sampling

* fix: split brands and categories

* fix: update excluded routes

* fix: excluded paths

* fix: exclude other sites

* fix: disable throttling

* chore: update dynamic sampling

* fix: remove brands from custom sampling since it should be picked up automatically

* chore: limit concurrency

* chore: remove concurrency limit, no visible change

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: jorgemoya

.github/workflows/regression-tests.yml

@@ -38,6 +38,6 @@ jobs:
         if: failure() || success()
         uses: actions/upload-artifact@v4
         with:
-          name: unlighthouse-${{ matrix.device }}-report
+          name: unlighthouse-vercel-${{ matrix.device }}-report
           path: './.unlighthouse/'
           include-hidden-files: 'true'

unlighthouse.config.ts

@@ -1,27 +1,51 @@
-
-import type { UserConfig } from 'unlighthouse';
+import type { UserConfig } from "unlighthouse";
 
 export default {
   ci: {
     buildStatic: true,
-    // Disabling the budget so we can audit and fix the issues first
+    reporter: "jsonExpanded",
     budget: {
       // "best-practices": 100,
       // "accessibility": 100,
       // "seo": 100,
+      // performance: 80,
+    },
+  },
+  scanner: {
+    // Run each page multiple times and use the median to absorb cold start
+    // outliers across all discovered pages.
+    samples: 3,
+    dynamicSampling: 5,
+    exclude: [
+      "/bundleb2b/",
+      "/invoices/",
+      "/bath/*/*",
+      "/garden/*/*",
+      "/kitchen/*/*",
+      "/publications/*/*",
+      "/early-access/*/*",
+      "/digital-test-product/",
+      "/blog/\\?tag=*",
+    ],
+    customSampling: {
+      "/smith-journal-13/|/dustpan-brush/|/utility-caddy/|/canvas-laundry-cart/|/laundry-detergent/|/tiered-wire-basket/|/oak-cheese-grater/|/1-l-le-parfait-jar/|/chemex-coffeemaker-3-cup/|/sample-able-brewing-system/|/orbit-terrarium-small/|/orbit-terrarium-large/|/fog-linen-chambray-towel-beige-stripe/|/zz-plant/":
+        { name: "PDP" },
+      "/shop-all/|/bath/|/garden/|/kitchen/|/publications/|/early-access/": {
+        name: "PLP",
+      },
     },
-  }, 
+    // Disable throttling to avoid issues with cold start and cold cache.
+    throttle: false,
+  },
   lighthouseOptions: {
-    // Disabling performance tests because lighthouse utilizes hardware throttling. This affects concurrently running tests which might lead to false positives.
-    // The best way to truly measure performance is to use real user metrics – Vercel's Speed Insights is a great tool for that.
-    onlyCategories: ['best-practices', 'accessibility', 'seo'],
+    onlyCategories: ["best-practices", "accessibility", "seo", "performance"],
     skipAudits: [
       // Disabling `is-crawlable` as it's more relevant for production sites.
-      'is-crawlable',
+      "is-crawlable",
       // Disabling third-party cookies because the only third-party cookies we have is provided through Cloudflare for our CDN, which is not relevant for our audits.
-      'third-party-cookies',
+      "third-party-cookies",
       // Disabling inspector issues as it's only providing third-party cookie issues, which are not relevant for our audits.
-      'inspector-issues',
-    ]
-  }
+      "inspector-issues",
+    ],
+  },
 } satisfies UserConfig;