Repository: ionic-team/ionic-framework
File: core/src/components/datetime/datetime.tsx (TypeScript)

Code before:
      this.initializeListeners();

      /**
       * TODO FW-2793: Datetime needs a frame to ensure that it
       * can properly scroll contents into view. As a result
       * we hide the scrollable content until after that frame
       * so users do not see the content quickly shifting. The downside
       * is that the content will pop into view a frame after. Maybe there
       * is a better way to handle this?
       */
      writeTask(() => {
        this.el.classList.add('datetime-ready');
      });
    };
    const visibleIO = new IntersectionObserver(visibleCallback, { threshold: 0.01, root: el });

    /**
     * Use raf to avoid a race condition between the component loading and
     * its display animation starting (such as when shown in a modal). This
     * could cause the datetime to start at a visibility of 0, erroneously
     * triggering the `hiddenIO` observer below.
     */
    raf(() => visibleIO?.observe(intersectionTrackerRef!));

    /**
     * Fallback: If IntersectionObserver never reports that the
     * datetime is visible but the host clearly has layout, ensure
     * we still initialize listeners and mark the component as ready.
     *
     * We schedule this after everything has had a chance to run.
     */
    setTimeout(() => {
      this.ensureReadyIfVisible();
    }, 100);

    /**
     * We need to clean up listeners when the datetime is hidden
     * in a popover/modal so that we can properly scroll containers
     * back into view if they are re-presented. When the datetime is hidden
     * the scroll areas have scroll widths/heights of 0px, so any snapping
     * we did originally has been lost.
     */
    const hiddenCallback = (entries: IntersectionObserverEntry[]) => {
      const ev = entries[0];
      if (ev.isIntersecting) {
        return;
      }

      this.destroyInteractionListeners();

      /**

Review comment (refactor):
```suggestion
   * TODO(FW-6931): Remove this fallback upon solving the root cause
   * Fallback: If IntersectionObserver never reports that the
```

Let's link to the follow-up JIRA ticket.

Code after:

      this.initializeListeners();

      /**
       * TODO FW-2793: Datetime needs a frame to ensure that it
       * can properly scroll contents into view. As a result
       * we hide the scrollable content until after that frame
       * so users do not see the content quickly shifting. The downside
       * is that the content will pop into view a frame after. Maybe there
       * is a better way to handle this?
       */
      writeTask(() => {
        this.el.classList.add('datetime-ready');
      });
    };
    const visibleIO = new IntersectionObserver(visibleCallback, { threshold: 0.01, root: el });

    /**
     * Use raf to avoid a race condition between the component loading and
     * its display animation starting (such as when shown in a modal). This
     * could cause the datetime to start at a visibility of 0, erroneously
     * triggering the `hiddenIO` observer below.
     */
    raf(() => visibleIO?.observe(intersectionTrackerRef!));

    /**
     * TODO(FW-6931): Remove this fallback upon solving the root cause
     * Fallback: If IntersectionObserver never reports that the
     * datetime is visible but the host clearly has layout, ensure
     * we still initialize listeners and mark the component as ready.
     *
     * We schedule this after everything has had a chance to run.
     */
    setTimeout(() => {
      this.ensureReadyIfVisible();
    }, 100);

    /**
     * We need to clean up listeners when the datetime is hidden
     * in a popover/modal so that we can properly scroll containers
     * back into view if they are re-presented. When the datetime is hidden
     * the scroll areas have scroll widths/heights of 0px, so any snapping
     * we did originally has been lost.
     */
    const hiddenCallback = (entries: IntersectionObserverEntry[]) => {
      const ev = entries[0];
      if (ev.isIntersecting) {
        return;
      }

      this.destroyInteractionListeners();