core: remove first-meaningful-paint metric (#16047)

cli/test/smokehouse/test-definitions/perf-preload.js

@@ -52,9 +52,6 @@ const expectations = {
       'speed-index': {
         score: '>=0.80', // primarily just making sure it didn't fail/go crazy, specific value isn't that important
       },
-      'first-meaningful-paint': {
-        score: '>=0.90', // primarily just making sure it didn't fail/go crazy, specific value isn't that important
-      },
       'interactive': {
         score: '>=0.90', // primarily just making sure it didn't fail/go crazy, specific value isn't that important
       },

core/audits/metrics/first-meaningful-paint.js

@@ -4,9 +4,10 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+// TODO(COMPAT): This is just a shell. Remove in future breaking release.
+
 import {Audit} from '../audit.js';
 import * as i18n from '../../lib/i18n/i18n.js';
-import {FirstMeaningfulPaint as ComputedFmp} from '../../computed/metrics/first-meaningful-paint.js';
 
 const UIStrings = {
   /** Description of the First Meaningful Paint (FMP) metric, which marks the time at which a majority of the content has been painted by the browser. This is displayed within a tooltip when the user hovers on the metric name to see more. No character length limits. The last sentence starting with 'Learn' becomes link text to additional documentation. */
@@ -32,55 +33,12 @@ class FirstMeaningfulPaint extends Audit {
   }
 
   /**
-   * @return {{mobile: {scoring: LH.Audit.ScoreOptions}, desktop: {scoring: LH.Audit.ScoreOptions}}}
-   */
-  static get defaultOptions() {
-    return {
-      mobile: {
-        // 25th and 5th percentiles HTTPArchive -> median and PODR, then p10 derived from them.
-        // https://bigquery.cloud.google.com/table/httparchive:lighthouse.2018_04_01_mobile?pli=1
-        // see https://www.desmos.com/calculator/i4znkdccut
-        scoring: {
-          p10: 2336,
-          median: 4000,
-        },
-      },
-      desktop: {
-        // SELECT QUANTILES(renderStart, 21) FROM [httparchive:summary_pages.2018_12_15_desktop] LIMIT 1000
-        scoring: {
-          p10: 934,
-          median: 1600,
-        },
-      },
-    };
-  }
-
-  /**
-   * Audits the page to give a score for First Meaningful Paint.
-   * @see https://github.com/GoogleChrome/lighthouse/issues/26
-   * @see https://docs.google.com/document/d/1BR94tJdZLsin5poeet0XoTW60M0SjvOJQttKT-JK8HI/view
-   * @param {LH.Artifacts} artifacts The artifacts from the gather phase.
-   * @param {LH.Audit.Context} context
    * @return {Promise<LH.Audit.Product>}
    */
-  static async audit(artifacts, context) {
-    const trace = artifacts.traces[Audit.DEFAULT_PASS];
-    const devtoolsLog = artifacts.devtoolsLogs[Audit.DEFAULT_PASS];
-    const gatherContext = artifacts.GatherContext;
-    const metricComputationData = {trace, devtoolsLog, gatherContext,
-      settings: context.settings, URL: artifacts.URL};
-    const metricResult = await ComputedFmp.request(metricComputationData, context);
-    const options = context.options[context.settings.formFactor];
-
-
+  static async audit() {
     return {
-      score: Audit.computeLogNormalScore(
-        options.scoring,
-        metricResult.timing
-      ),
-      numericValue: metricResult.timing,
-      numericUnit: 'millisecond',
-      displayValue: str_(i18n.UIStrings.seconds, {timeInMs: metricResult.timing}),
+      score: null,
+      notApplicable: true,
     };
   }
 }

core/audits/predictive-perf.js

@@ -7,7 +7,6 @@
 import {Audit} from './audit.js';
 import * as i18n from '../lib/i18n/i18n.js';
 import {LanternFirstContentfulPaint} from '../computed/metrics/lantern-first-contentful-paint.js';
-import {LanternFirstMeaningfulPaint} from '../computed/metrics/lantern-first-meaningful-paint.js';
 import {LanternInteractive} from '../computed/metrics/lantern-interactive.js';
 import {LanternSpeedIndex} from '../computed/metrics/lantern-speed-index.js';
 import {LanternLargestContentfulPaint} from '../computed/metrics/lantern-largest-contentful-paint.js';
@@ -52,7 +51,6 @@ class PredictivePerf extends Audit {
     const settings = JSON.parse(JSON.stringify(defaultSettings)); // Use default settings.
     const computationData = {trace, devtoolsLog, gatherContext, settings, URL};
     const fcp = await LanternFirstContentfulPaint.request(computationData, context);
-    const fmp = await LanternFirstMeaningfulPaint.request(computationData, context);
     const tti = await LanternInteractive.request(computationData, context);
     const si = await LanternSpeedIndex.request(computationData, context);
     const lcp = await LanternLargestContentfulPaint.request(computationData, context);
@@ -64,10 +62,6 @@ class PredictivePerf extends Audit {
       optimisticFCP: fcp.optimisticEstimate.timeInMs,
       pessimisticFCP: fcp.pessimisticEstimate.timeInMs,
 
-      roughEstimateOfFMP: fmp.timing,
-      optimisticFMP: fmp.optimisticEstimate.timeInMs,
-      pessimisticFMP: fmp.pessimisticEstimate.timeInMs,
-
       roughEstimateOfTTI: tti.timing,
       optimisticTTI: tti.optimisticEstimate.timeInMs,
       pessimisticTTI: tti.pessimisticEstimate.timeInMs,

core/computed/metrics/timing-summary.js

@@ -9,7 +9,6 @@ import {ProcessedNavigation} from '../processed-navigation.js';
 import {Speedline} from '../speedline.js';
 import {FirstContentfulPaint} from './first-contentful-paint.js';
 import {FirstContentfulPaintAllFrames} from './first-contentful-paint-all-frames.js';
-import {FirstMeaningfulPaint} from './first-meaningful-paint.js';
 import {LargestContentfulPaint} from './largest-contentful-paint.js';
 import {LargestContentfulPaintAllFrames} from './largest-contentful-paint-all-frames.js';
 import {Interactive} from './interactive.js';
@@ -51,7 +50,6 @@ class TimingSummary {
     const speedline = await Speedline.request(trace, context);
     const firstContentfulPaint = await requestOrUndefined(FirstContentfulPaint, metricComputationData);
     const firstContentfulPaintAllFrames = await requestOrUndefined(FirstContentfulPaintAllFrames, metricComputationData);
-    const firstMeaningfulPaint = await requestOrUndefined(FirstMeaningfulPaint, metricComputationData);
     const largestContentfulPaint = await requestOrUndefined(LargestContentfulPaint, metricComputationData);
     const largestContentfulPaintAllFrames = await requestOrUndefined(LargestContentfulPaintAllFrames, metricComputationData);
     const interactive = await requestOrUndefined(Interactive, metricComputationData);
@@ -74,8 +72,6 @@ class TimingSummary {
       firstContentfulPaintTs: firstContentfulPaint?.timestamp,
       firstContentfulPaintAllFrames: firstContentfulPaintAllFrames?.timing,
       firstContentfulPaintAllFramesTs: firstContentfulPaintAllFrames?.timestamp,
-      firstMeaningfulPaint: firstMeaningfulPaint?.timing,
-      firstMeaningfulPaintTs: firstMeaningfulPaint?.timestamp,
       largestContentfulPaint: largestContentfulPaint?.timing,
       largestContentfulPaintTs: largestContentfulPaint?.timestamp,
       largestContentfulPaintAllFrames: largestContentfulPaintAllFrames?.timing,
@@ -107,8 +103,6 @@ class TimingSummary {
       observedFirstContentfulPaintTs: processedNavigation?.timestamps.firstContentfulPaint,
       observedFirstContentfulPaintAllFrames: processedNavigation?.timings.firstContentfulPaintAllFrames,
       observedFirstContentfulPaintAllFramesTs: processedNavigation?.timestamps.firstContentfulPaintAllFrames,
-      observedFirstMeaningfulPaint: processedNavigation?.timings.firstMeaningfulPaint,
-      observedFirstMeaningfulPaintTs: processedNavigation?.timestamps.firstMeaningfulPaint,
       observedLargestContentfulPaint: processedNavigation?.timings.largestContentfulPaint,
       observedLargestContentfulPaintTs: processedNavigation?.timestamps.largestContentfulPaint,
       observedLargestContentfulPaintAllFrames: processedNavigation?.timings.largestContentfulPaintAllFrames,

core/lib/tracehouse/trace-processor.js

@@ -9,7 +9,7 @@
  * various tools. This artifact will take a trace and then:
  *
  * 1. Find the TracingStartedInPage and navigationStart events of our intended tab & frame.
- * 2. Find the firstContentfulPaint and marked firstMeaningfulPaint events
+ * 2. Find the firstContentfulPaint and marked largestContentfulPaint events
  * 3. Isolate only the trace events from the tab's process (including all threads like compositor)
  *      * Sort those trace events in chronological order (as order isn't guaranteed)
  * 4. Return all those items in one handy bundle.
@@ -835,7 +835,6 @@ class TraceProcessor {
         firstPaint: frameTimings.timings.firstPaint,
         firstContentfulPaint: frameTimings.timings.firstContentfulPaint,
         firstContentfulPaintAllFrames: getTiming(fcpAllFramesEvt.ts),
-        firstMeaningfulPaint: frameTimings.timings.firstMeaningfulPaint,
         largestContentfulPaint: frameTimings.timings.largestContentfulPaint,
         largestContentfulPaintAllFrames: maybeGetTiming(lcpAllFramesEvt?.ts),
         load: frameTimings.timings.load,
@@ -847,7 +846,6 @@ class TraceProcessor {
         firstPaint: frameTimings.timestamps.firstPaint,
         firstContentfulPaint: frameTimings.timestamps.firstContentfulPaint,
         firstContentfulPaintAllFrames: fcpAllFramesEvt.ts,
-        firstMeaningfulPaint: frameTimings.timestamps.firstMeaningfulPaint,
         largestContentfulPaint: frameTimings.timestamps.largestContentfulPaint,
         largestContentfulPaintAllFrames: lcpAllFramesEvt?.ts,
         load: frameTimings.timestamps.load,
@@ -857,12 +855,10 @@ class TraceProcessor {
       firstPaintEvt: frameTimings.firstPaintEvt,
       firstContentfulPaintEvt: frameTimings.firstContentfulPaintEvt,
       firstContentfulPaintAllFramesEvt: fcpAllFramesEvt,
-      firstMeaningfulPaintEvt: frameTimings.firstMeaningfulPaintEvt,
       largestContentfulPaintEvt: frameTimings.largestContentfulPaintEvt,
       largestContentfulPaintAllFramesEvt: lcpAllFramesEvt,
       loadEvt: frameTimings.loadEvt,
       domContentLoadedEvt: frameTimings.domContentLoadedEvt,
-      fmpFellBack: frameTimings.fmpFellBack,
       lcpInvalidated: frameTimings.lcpInvalidated,
     };
   }
@@ -970,28 +966,6 @@ class TraceProcessor {
       throw this.createNoFirstContentfulPaintError();
     }
 
-    // fMP will follow at/after the FP
-    let firstMeaningfulPaint = frameEvents.find(
-      e => e.name === 'firstMeaningfulPaint' && e.ts > timeOriginEvt.ts
-    );
-    let fmpFellBack = false;
-
-    // If there was no firstMeaningfulPaint event found in the trace, the network idle detection
-    // may have not been triggered before Lighthouse finished tracing.
-    // In this case, we'll use the last firstMeaningfulPaintCandidate we can find.
-    // However, if no candidates were found (a bogus trace, likely), we fail.
-    if (!firstMeaningfulPaint) {
-      const fmpCand = 'firstMeaningfulPaintCandidate';
-      fmpFellBack = true;
-      log.verbose('TraceProcessor',
-        `No firstMeaningfulPaint found, falling back to last ${fmpCand}`);
-      const lastCandidate = frameEvents.filter(e => e.name === fmpCand).pop();
-      if (!lastCandidate) {
-        log.verbose('TraceProcessor', 'No `firstMeaningfulPaintCandidate` events found in trace');
-      }
-      firstMeaningfulPaint = lastCandidate;
-    }
-
     // This function accepts events spanning multiple frames, but this usage will only provide events from the main frame.
     const lcpResult = this.computeValidLCPAllFrames(frameEvents, timeOriginEvt);
 
@@ -1007,7 +981,6 @@ class TraceProcessor {
       timeOrigin: timeOriginEvt.ts,
       firstPaint: getTimestamp(firstPaint),
       firstContentfulPaint: firstContentfulPaint.ts,
-      firstMeaningfulPaint: getTimestamp(firstMeaningfulPaint),
       largestContentfulPaint: getTimestamp(lcpResult.lcp),
       load: getTimestamp(load),
       domContentLoaded: getTimestamp(domContentLoaded),
@@ -1022,7 +995,6 @@ class TraceProcessor {
       timeOrigin: 0,
       firstPaint: maybeGetTiming(timestamps.firstPaint),
       firstContentfulPaint: getTiming(timestamps.firstContentfulPaint),
-      firstMeaningfulPaint: maybeGetTiming(timestamps.firstMeaningfulPaint),
       largestContentfulPaint: maybeGetTiming(timestamps.largestContentfulPaint),
       load: maybeGetTiming(timestamps.load),
       domContentLoaded: maybeGetTiming(timestamps.domContentLoaded),
@@ -1034,11 +1006,9 @@ class TraceProcessor {
       timeOriginEvt: timeOriginEvt,
       firstPaintEvt: firstPaint,
       firstContentfulPaintEvt: firstContentfulPaint,
-      firstMeaningfulPaintEvt: firstMeaningfulPaint,
       largestContentfulPaintEvt: lcpResult.lcp,
       loadEvt: load,
       domContentLoadedEvt: domContentLoaded,
-      fmpFellBack,
       lcpInvalidated: lcpResult.invalidated,
     };
   }