Function hover

src/cdk/menu/menu.spec.ts:191–216

* Fakes mouse hover events from some source point to some target point. Along the way, emits * mouse move events and mouse enter events when the element under the mouse changes. * * It assumes that moves will occur left to right and down. * @param from the starting point

(from: Point, to: Point, inMenu: HTMLElement, duration: number)

       * @return the number of elements the mouse entered into.
       */
      async function hover(from: Point, to: Point, inMenu: HTMLElement, duration: number) {
        const getNextPoint = getNextPointIterator(from, to);

        let currentPoint: Point | null = from;
        let currElement = getElementAt(currentPoint);

        const timeout = duration / Math.abs(to.x - from.x);

        let numEnters = 0;
        while (currentPoint) {
          mousemove(inMenu, currentPoint);
          const nextElement = getElementAt(currentPoint);
          if (nextElement !== currElement && nextElement instanceof HTMLButtonElement) {
            numEnters++;
            mouseout(currElement);
            mouseenter(nextElement, currentPoint);
            currElement = nextElement;
            fixture.detectChanges();
          }
          currentPoint = getNextPoint();
          if (timeout > 0) {
            await wait(timeout);
          }
        }
        return numEnters;
      }

      /**
       * Get a function which determines the next point to generate when moving from one point to