From 4ce741a8712b80567246b1678d252a1608f5e677 Mon Sep 17 00:00:00 2001
From: Adriana Ixba <ixbaadriana@gmail.com>
Date: Tue, 11 Jul 2023 15:16:12 -0700
Subject: [PATCH] core(render-blocking-resources): add FCP and LCP savings
 (#15238)

---
 core/audits/byte-efficiency/render-blocking-resources.js        | 1 +
 .../audits/byte-efficiency/render-blocking-resources-test.js    | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/core/audits/byte-efficiency/render-blocking-resources.js b/core/audits/byte-efficiency/render-blocking-resources.js
index f43a4a8d8622..3dd6060bcddc 100644
--- a/core/audits/byte-efficiency/render-blocking-resources.js
+++ b/core/audits/byte-efficiency/render-blocking-resources.js
@@ -299,6 +299,7 @@ class RenderBlockingResources extends Audit {
       numericValue: wastedMs,
       numericUnit: 'millisecond',
       details,
+      metricSavings: {FCP: wastedMs, LCP: wastedMs},
     };
   }
 }
diff --git a/core/test/audits/byte-efficiency/render-blocking-resources-test.js b/core/test/audits/byte-efficiency/render-blocking-resources-test.js
index 1ea43804c454..d86cc5713f82 100644
--- a/core/test/audits/byte-efficiency/render-blocking-resources-test.js
+++ b/core/test/audits/byte-efficiency/render-blocking-resources-test.js
@@ -41,6 +41,7 @@ describe('Render blocking resources audit', () => {
     const result = await RenderBlockingResourcesAudit.audit(artifacts, {settings, computedCache});
     assert.equal(result.score, 1);
     assert.equal(result.numericValue, 0);
+    assert.deepStrictEqual(result.metricSavings, {FCP: 0, LCP: 0});
   });
 
   it('evaluates amp page correctly', async () => {
@@ -87,6 +88,7 @@ describe('Render blocking resources audit', () => {
       // it look like Montserrat starts after Fira Sans finishes. It would be preferred
       // if eventual simulation improvements list Montserrat here as well.
     ]);
+    expect(result.metricSavings).toEqual({FCP: 450, LCP: 450});
   });
 
   describe('#estimateSavingsWithGraphs', () => {