From 8eff962cab608341a6f2fedc640a0e32d96f26e2 Mon Sep 17 00:00:00 2001 From: altaf-creator Date: Sun, 9 Nov 2025 11:15:19 +0800 Subject: pain --- frontend-old/node_modules/web-vitals/src/onFCP.ts | 95 +++++++++++++++++++++++ 1 file changed, 95 insertions(+) create mode 100644 frontend-old/node_modules/web-vitals/src/onFCP.ts (limited to 'frontend-old/node_modules/web-vitals/src/onFCP.ts') diff --git a/frontend-old/node_modules/web-vitals/src/onFCP.ts b/frontend-old/node_modules/web-vitals/src/onFCP.ts new file mode 100644 index 0000000..f2a3625 --- /dev/null +++ b/frontend-old/node_modules/web-vitals/src/onFCP.ts @@ -0,0 +1,95 @@ +/* + * Copyright 2020 Google LLC + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * https://www.apache.org/licenses/LICENSE-2.0 + * + * 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. + */ + +import {onBFCacheRestore} from './lib/bfcache.js'; +import {bindReporter} from './lib/bindReporter.js'; +import {doubleRAF} from './lib/doubleRAF.js'; +import {getActivationStart} from './lib/getActivationStart.js'; +import {getVisibilityWatcher} from './lib/getVisibilityWatcher.js'; +import {initMetric} from './lib/initMetric.js'; +import {observe} from './lib/observe.js'; +import {whenActivated} from './lib/whenActivated.js'; +import {FCPMetric, MetricRatingThresholds, ReportOpts} from './types.js'; + +/** Thresholds for FCP. See https://web.dev/articles/fcp#what_is_a_good_fcp_score */ +export const FCPThresholds: MetricRatingThresholds = [1800, 3000]; + +/** + * Calculates the [FCP](https://web.dev/articles/fcp) value for the current page and + * calls the `callback` function once the value is ready, along with the + * relevant `paint` performance entry used to determine the value. The reported + * value is a `DOMHighResTimeStamp`. + */ +export const onFCP = ( + onReport: (metric: FCPMetric) => void, + opts?: ReportOpts, +) => { + // Set defaults + opts = opts || {}; + + whenActivated(() => { + const visibilityWatcher = getVisibilityWatcher(); + let metric = initMetric('FCP'); + let report: ReturnType; + + const handleEntries = (entries: FCPMetric['entries']) => { + entries.forEach((entry) => { + if (entry.name === 'first-contentful-paint') { + po!.disconnect(); + + // Only report if the page wasn't hidden prior to the first paint. + if (entry.startTime < visibilityWatcher.firstHiddenTime) { + // The activationStart reference is used because FCP should be + // relative to page activation rather than navigation start if the + // page was prerendered. But in cases where `activationStart` occurs + // after the FCP, this time should be clamped at 0. + metric.value = Math.max(entry.startTime - getActivationStart(), 0); + metric.entries.push(entry); + report(true); + } + } + }); + }; + + const po = observe('paint', handleEntries); + + if (po) { + report = bindReporter( + onReport, + metric, + FCPThresholds, + opts!.reportAllChanges, + ); + + // Only report after a bfcache restore if the `PerformanceObserver` + // successfully registered or the `paint` entry exists. + onBFCacheRestore((event) => { + metric = initMetric('FCP'); + report = bindReporter( + onReport, + metric, + FCPThresholds, + opts!.reportAllChanges, + ); + + doubleRAF(() => { + metric.value = performance.now() - event.timeStamp; + report(true); + }); + }); + } + }); +}; -- cgit v1.2.3