report: workaround google3 fragment link bug

[connorjclark]

replacing #12995

basically option 3 from #12995 (comment) , but undoing the change such that ReportGenerator is not necessary.

I considered only having _fixFragmentLinks called when necessary, but it's nice to have this code exercised in all reports because it means we'll notice quicker if it ever breaks.

[paulirish]

2. click handler: wrapper.addEventListener('click', () => window.location.href = category.id). Downsides:

   • we should avoid overriding default behavior when possible (let a link be a link). Arguably setting fully qualified links (option 1) is the semantically correct thing to do when we can't rely on the <base> url rather than setting a relative fragment url and overriding the behavior on click anyways.

I think theres another alternative that I didnt see in that discussion. (very possible i didnt look far, tho).. cc @brendankenny since you were innit

we use preventDefault and scrollIntoView:

document.querySelectorAll('a.lh-gauge__wrapper[href^="#"]').forEach(elem => {
    elem.addEventListener('click', e => {
        e.preventDefault();
        const target = document.querySelector(elem.getAttribute('href')); // .href would be fully qualified...
        target.scrollIntoView();
          
    })
})

by default.. this wouldn't update the URL.. but we could still allow that (in certain scenarios if we we wanted) by adding this into the handler.

        const url = new URL(elem.getAttribute('href'), location.href)      
        history.pushState({}, '', url);

scrollIntoView is totes magic... that direction seems a lot more promising to me.