Update app and tooling

node_modules/web-vitals/src/getFID.ts

@@ -0,0 +1,88 @@
+/*
+ * 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 {bindReporter} from './lib/bindReporter.js';
+import {getFirstHidden} from './lib/getFirstHidden.js';
+import {initMetric} from './lib/initMetric.js';
+import {observe, PerformanceEntryHandler} from './lib/observe.js';
+import {onHidden} from './lib/onHidden.js';
+import {ReportHandler} from './types.js';
+
+
+interface FIDPolyfillCallback {
+  (value: number, event: Event): void;
+}
+
+interface FIDPolyfill {
+  onFirstInputDelay: (onReport: FIDPolyfillCallback) => void;
+}
+
+declare global {
+  interface Window {
+    perfMetrics: FIDPolyfill;
+  }
+}
+
+// https://wicg.github.io/event-timing/#sec-performance-event-timing
+interface PerformanceEventTiming extends PerformanceEntry {
+  processingStart: DOMHighResTimeStamp;
+  cancelable?: boolean;
+  target?: Element;
+}
+
+export const getFID = (onReport: ReportHandler) => {
+  const metric = initMetric('FID');
+  const firstHidden = getFirstHidden();
+
+  const entryHandler = (entry: PerformanceEventTiming) => {
+    // Only report if the page wasn't hidden prior to the first input.
+    if (entry.startTime < firstHidden.timeStamp) {
+      metric.value = entry.processingStart - entry.startTime;
+      metric.entries.push(entry);
+      metric.isFinal = true;
+      report();
+    }
+  };
+
+  const po = observe('first-input', entryHandler as PerformanceEntryHandler);
+  const report = bindReporter(onReport, metric, po);
+
+  if (po) {
+    onHidden(() => {
+      po.takeRecords().map(entryHandler as PerformanceEntryHandler);
+      po.disconnect();
+    }, true);
+  } else {
+    if (window.perfMetrics && window.perfMetrics.onFirstInputDelay) {
+      window.perfMetrics.onFirstInputDelay((value: number, event: Event) => {
+        // Only report if the page wasn't hidden prior to the first input.
+        if (event.timeStamp < firstHidden.timeStamp) {
+          metric.value = value;
+          metric.isFinal = true;
+          metric.entries = [{
+            entryType: 'first-input',
+            name: event.type,
+            target: event.target,
+            cancelable: event.cancelable,
+            startTime: event.timeStamp,
+            processingStart: event.timeStamp + value,
+          } as PerformanceEventTiming];
+          report();
+        }
+      });
+    }
+  }
+};