core: update FCP score curve (#12556)

GoogleChrome · May 25, 2021 · 3b3df20 · 3b3df20
1 parent 73c7e85
commit 3b3df20
Show file tree

Hide file tree

Showing 6 changed files with 40 additions and 22 deletions.
diff --git a/lighthouse-core/audits/metrics/first-contentful-paint-3g.js b/lighthouse-core/audits/metrics/first-contentful-paint-3g.js
@@ -29,12 +29,11 @@ class FirstContentfulPaint3G extends Audit {
    */
   static get defaultOptions() {
     return {
-      // 25th and 5th percentiles HTTPArchive on Fast 3G -> multiply by 1.5 for RTT differential -> median and PODR
-      // p10 is then derived from them.
-      // https://bigquery.cloud.google.com/table/httparchive:lighthouse.2018_04_01_mobile?pli=1
-      // https://www.desmos.com/calculator/fflcrsn9sj
-      p10: 3504,
-      median: 6000,
+      // 25th and 8th percentiles HTTPArchive on Slow 4G -> multiply by 1.5 for RTT differential -> median and p10.
+      // https://bigquery.cloud.google.com/table/httparchive:lighthouse.2021_05_01_mobile
+      // https://www.desmos.com/calculator/xi5oympawp
+      p10: 2700,
+      median: 4500,
     };
   }
 

diff --git a/lighthouse-core/audits/metrics/first-contentful-paint.js b/lighthouse-core/audits/metrics/first-contentful-paint.js
@@ -37,16 +37,16 @@ class FirstContentfulPaint extends Audit {
   static get defaultOptions() {
     return {
       mobile: {
-        // 25th and 5th percentiles HTTPArchive -> median and PODR, then p10 is derived from them.
-        // https://bigquery.cloud.google.com/table/httparchive:lighthouse.2018_04_01_mobile?pli=1
-        // see https://www.desmos.com/calculator/oqlvmezbze
+        // 25th and 8th percentiles HTTPArchive -> median and p10.
+        // https://bigquery.cloud.google.com/table/httparchive:lighthouse.2021_05_01_mobile
+        // see https://www.desmos.com/calculator/6wi8rhipve
         scoring: {
-          p10: 2336,
-          median: 4000,
+          p10: 1800,
+          median: 3000,
         },
       },
       desktop: {
-        // SELECT QUANTILES(renderStart, 21) FROM [httparchive:summary_pages.2018_12_15_desktop] LIMIT 1000
+        // SELECT QUANTILES(renderStart, 21) FROM [httparchive:summary_pages.2020_07_01_desktop] LIMIT 1000
         scoring: {
           p10: 934,
           median: 1600,

diff --git a/lighthouse-core/test/audits/metrics/first-contentful-paint-3g-test.js b/lighthouse-core/test/audits/metrics/first-contentful-paint-3g-test.js
@@ -28,7 +28,7 @@ describe('Performance: first-contentful-paint-3g audit', () => {
     // Use InlineSnapshot here so changes to Lantern coefficients can be easily updated en masse
     expect({score: result.score, value: Math.round(result.numericValue)}).toMatchInlineSnapshot(`
 Object {
-  "score": 0.99,
+  "score": 0.97,
   "value": 2087,
 }
 `);

diff --git a/lighthouse-core/test/audits/metrics/first-contentful-paint-test.js b/lighthouse-core/test/audits/metrics/first-contentful-paint-test.js
@@ -4,14 +4,17 @@
  * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
  */
 'use strict';
-const Audit = require('../../../audits/metrics/first-contentful-paint.js');
+const FcpAudit = require('../../../audits/metrics/first-contentful-paint.js');
 const assert = require('assert').strict;
-const options = Audit.defaultOptions;
+const options = FcpAudit.defaultOptions;
 const constants = require('../../../config/constants.js');
 
 const pwaTrace = require('../../fixtures/traces/progressive-app-m60.json');
 const pwaDevtoolsLog = require('../../fixtures/traces/progressive-app-m60.devtools.log.json');
 
+const frameTrace = require('../../fixtures/traces/frame-metrics-m90.json');
+const frameDevtoolsLog = require('../../fixtures/traces/frame-metrics-m90.devtools.log.json');
+
 /**
  * @param {{
  * {LH.SharedFlagsSettings['formFactor']} formFactor
@@ -35,16 +38,32 @@ describe('Performance: first-contentful-paint audit', () => {
   it('evaluates valid input correctly', async () => {
     const artifacts = {
       traces: {
-        [Audit.DEFAULT_PASS]: pwaTrace,
+        [FcpAudit.DEFAULT_PASS]: pwaTrace,
       },
       devtoolsLogs: {
-        [Audit.DEFAULT_PASS]: pwaDevtoolsLog,
+        [FcpAudit.DEFAULT_PASS]: pwaDevtoolsLog,
       },
     };
 
     const context = getFakeContext({formFactor: 'mobile', throttlingMethod: 'provided'});
-    const result = await Audit.audit(artifacts, context);
+    const result = await FcpAudit.audit(artifacts, context);
     assert.equal(result.score, 1);
     assert.equal(result.numericValue, 498.87);
   });
+
+  it('evaluates a modern trace correctly', async () => {
+    const artifacts = {
+      traces: {
+        [FcpAudit.DEFAULT_PASS]: frameTrace,
+      },
+      devtoolsLogs: {
+        [FcpAudit.DEFAULT_PASS]: frameDevtoolsLog,
+      },
+    };
+
+    const context = getFakeContext({formFactor: 'mobile', throttlingMethod: 'provided'});
+    const result = await FcpAudit.audit(artifacts, context);
+    assert.equal(result.score, 0.06);
+    assert.equal(result.numericValue, 5668.275);
+  });
 });
diff --git a/lighthouse-core/test/report/report-generator-test.js b/lighthouse-core/test/report/report-generator-test.js
@@ -104,8 +104,8 @@ describe('ReportGenerator', () => {
       expect(lines.length).toBeGreaterThan(100);
       expect(lines.slice(0, 3).join('\n')).toMatchInlineSnapshot(`
         "requestedUrl,finalUrl,category,name,title,type,score
-        \\"http://localhost:10200/dobetterweb/dbw_tester.html\\",\\"http://localhost:10200/dobetterweb/dbw_tester.html\\",\\"Performance\\",\\"performance-score\\",\\"Overall Performance Category Score\\",\\"numeric\\",\\"0.64\\"
-        \\"http://localhost:10200/dobetterweb/dbw_tester.html\\",\\"http://localhost:10200/dobetterweb/dbw_tester.html\\",\\"Performance\\",\\"first-contentful-paint\\",\\"First Contentful Paint\\",\\"numeric\\",\\"0.51\\"
+        \\"http://localhost:10200/dobetterweb/dbw_tester.html\\",\\"http://localhost:10200/dobetterweb/dbw_tester.html\\",\\"Performance\\",\\"performance-score\\",\\"Overall Performance Category Score\\",\\"numeric\\",\\"0.6\\"
+        \\"http://localhost:10200/dobetterweb/dbw_tester.html\\",\\"http://localhost:10200/dobetterweb/dbw_tester.html\\",\\"Performance\\",\\"first-contentful-paint\\",\\"First Contentful Paint\\",\\"numeric\\",\\"0.24\\"
         "
       `);
 

diff --git a/lighthouse-core/test/results/sample_v2.json b/lighthouse-core/test/results/sample_v2.json
@@ -69,7 +69,7 @@
       "id": "first-contentful-paint",
       "title": "First Contentful Paint",
       "description": "First Contentful Paint marks the time at which the first text or image is painted. [Learn more](https://web.dev/first-contentful-paint/).",
-      "score": 0.51,
+      "score": 0.24,
       "scoreDisplayMode": "numeric",
       "numericValue": 3969.135,
       "numericUnit": "millisecond",
@@ -5277,7 +5277,7 @@
         }
       ],
       "id": "performance",
-      "score": 0.64
+      "score": 0.6
     },
     "accessibility": {
       "title": "Accessibility",