Convert frontend code to typescript (#31559)

None of the frontend js/ts files was touched besides these two commands
(edit: no longer true, I touched one file in
61105d0618
because of a deprecation that was not showing before the rename).

`tsc` currently reports 778 errors, so I have disabled it in CI as
planned.

Everything appears to work fine.

web_src/js/features/stopwatch.ts

@@ -0,0 +1,166 @@
+import {createTippy} from '../modules/tippy.ts';
+import {GET} from '../modules/fetch.ts';
+import {hideElem, showElem} from '../utils/dom.ts';
+import {logoutFromWorker} from '../modules/worker.ts';
+
+const {appSubUrl, notificationSettings, enableTimeTracking, assetVersionEncoded} = window.config;
+
+export function initStopwatch() {
+  if (!enableTimeTracking) {
+    return;
+  }
+
+  const stopwatchEls = document.querySelectorAll('.active-stopwatch');
+  const stopwatchPopup = document.querySelector('.active-stopwatch-popup');
+
+  if (!stopwatchEls.length || !stopwatchPopup) {
+    return;
+  }
+
+  // global stop watch (in the head_navbar), it should always work in any case either the EventSource or the PeriodicPoller is used.
+  const seconds = stopwatchEls[0]?.getAttribute('data-seconds');
+  if (seconds) {
+    updateStopwatchTime(parseInt(seconds));
+  }
+
+  for (const stopwatchEl of stopwatchEls) {
+    stopwatchEl.removeAttribute('href'); // intended for noscript mode only
+
+    createTippy(stopwatchEl, {
+      content: stopwatchPopup.cloneNode(true),
+      placement: 'bottom-end',
+      trigger: 'click',
+      maxWidth: 'none',
+      interactive: true,
+      hideOnClick: true,
+      theme: 'default',
+    });
+  }
+
+  let usingPeriodicPoller = false;
+  const startPeriodicPoller = (timeout) => {
+    if (timeout <= 0 || !Number.isFinite(timeout)) return;
+    usingPeriodicPoller = true;
+    setTimeout(() => updateStopwatchWithCallback(startPeriodicPoller, timeout), timeout);
+  };
+
+  // if the browser supports EventSource and SharedWorker, use it instead of the periodic poller
+  if (notificationSettings.EventSourceUpdateTime > 0 && window.EventSource && window.SharedWorker) {
+    // Try to connect to the event source via the shared worker first
+    const worker = new SharedWorker(`${__webpack_public_path__}js/eventsource.sharedworker.js?v=${assetVersionEncoded}`, 'notification-worker');
+    worker.addEventListener('error', (event) => {
+      console.error('worker error', event);
+    });
+    worker.port.addEventListener('messageerror', () => {
+      console.error('unable to deserialize message');
+    });
+    worker.port.postMessage({
+      type: 'start',
+      url: `${window.location.origin}${appSubUrl}/user/events`,
+    });
+    worker.port.addEventListener('message', (event) => {
+      if (!event.data || !event.data.type) {
+        console.error('unknown worker message event', event);
+        return;
+      }
+      if (event.data.type === 'stopwatches') {
+        updateStopwatchData(JSON.parse(event.data.data));
+      } else if (event.data.type === 'no-event-source') {
+        // browser doesn't support EventSource, falling back to periodic poller
+        if (!usingPeriodicPoller) startPeriodicPoller(notificationSettings.MinTimeout);
+      } else if (event.data.type === 'error') {
+        console.error('worker port event error', event.data);
+      } else if (event.data.type === 'logout') {
+        if (event.data.data !== 'here') {
+          return;
+        }
+        worker.port.postMessage({
+          type: 'close',
+        });
+        worker.port.close();
+        logoutFromWorker();
+      } else if (event.data.type === 'close') {
+        worker.port.postMessage({
+          type: 'close',
+        });
+        worker.port.close();
+      }
+    });
+    worker.port.addEventListener('error', (e) => {
+      console.error('worker port error', e);
+    });
+    worker.port.start();
+    window.addEventListener('beforeunload', () => {
+      worker.port.postMessage({
+        type: 'close',
+      });
+      worker.port.close();
+    });
+
+    return;
+  }
+
+  startPeriodicPoller(notificationSettings.MinTimeout);
+}
+
+async function updateStopwatchWithCallback(callback, timeout) {
+  const isSet = await updateStopwatch();
+
+  if (!isSet) {
+    timeout = notificationSettings.MinTimeout;
+  } else if (timeout < notificationSettings.MaxTimeout) {
+    timeout += notificationSettings.TimeoutStep;
+  }
+
+  callback(timeout);
+}
+
+async function updateStopwatch() {
+  const response = await GET(`${appSubUrl}/user/stopwatches`);
+  if (!response.ok) {
+    console.error('Failed to fetch stopwatch data');
+    return false;
+  }
+  const data = await response.json();
+  return updateStopwatchData(data);
+}
+
+function updateStopwatchData(data) {
+  const watch = data[0];
+  const btnEls = document.querySelectorAll('.active-stopwatch');
+  if (!watch) {
+    hideElem(btnEls);
+  } else {
+    const {repo_owner_name, repo_name, issue_index, seconds} = watch;
+    const issueUrl = `${appSubUrl}/${repo_owner_name}/${repo_name}/issues/${issue_index}`;
+    document.querySelector('.stopwatch-link')?.setAttribute('href', issueUrl);
+    document.querySelector('.stopwatch-commit')?.setAttribute('action', `${issueUrl}/times/stopwatch/toggle`);
+    document.querySelector('.stopwatch-cancel')?.setAttribute('action', `${issueUrl}/times/stopwatch/cancel`);
+    const stopwatchIssue = document.querySelector('.stopwatch-issue');
+    if (stopwatchIssue) stopwatchIssue.textContent = `${repo_owner_name}/${repo_name}#${issue_index}`;
+    updateStopwatchTime(seconds);
+    showElem(btnEls);
+  }
+  return Boolean(data.length);
+}
+
+// TODO: This flickers on page load, we could avoid this by making a custom
+// element to render time periods. Feeding a datetime in backend does not work
+// when time zone between server and client differs.
+function updateStopwatchTime(seconds) {
+  if (!Number.isFinite(seconds)) return;
+  const datetime = (new Date(Date.now() - seconds * 1000)).toISOString();
+  for (const parent of document.querySelectorAll('.header-stopwatch-dot')) {
+    const existing = parent.querySelector(':scope > relative-time');
+    if (existing) {
+      existing.setAttribute('datetime', datetime);
+    } else {
+      const el = document.createElement('relative-time');
+      el.setAttribute('format', 'micro');
+      el.setAttribute('datetime', datetime);
+      el.setAttribute('lang', 'en-US');
+      el.setAttribute('title', ''); // make <relative-time> show no title and therefor no tooltip
+      parent.append(el);
+    }
+  }
+}