Halloween's over - let's stamp out these ZOMBIE merchandising components

[jbreckmckye]

This is a fix to a slightly obscure spacefinder bug.

Sometimes, inline merchandising components are added in spaces they really don't belong:

What's happening here? Aren't these things supposed to give headings clearance, because they're left aligned?

The rules they use certainly say so...

lenientRules.selectors[' > h2'].minAbove = 20;

So is this just spacefinder on the fritz? Let's take a look at the comparison it does between the elements for the purposes of the inlineMercPromise...

Both isMinAbove and isMinBelow are false for this check. So spacefinder considers the paragraph in question ineligible for the inline merchandising component. Yet it displays there all the same. What gives?

A look at article-body-adverts.js gives the answer...

if (config.page.hasInlineMerchandise) {
    adNames.unshift(['im', 'im']);

    inlineMercPromise = spacefinder.getParaWithSpace(lenientRules).then(function (space) {
        return insertAdAtP(space);
    });
} else {
   inlineMercPromise = Promise.resolve(null);
}

We're adding the inline merchandising ad names - ['im', 'im'] - regardless of whether the spacefinder actually finds a space for the IM component. So the next time we do add an advert, it'll be an IM component instead, even though there's no space for such a thing. Thus I have termed it a zombie merchandising component.

Originally, this wouldn't have been a problem, because the IM element was added with lenientRules - how would we later find ad spaces with stricter rules? But the lenientRules have been subtly changed at some point - they now have a h2 clearance that wouldn't otherwise be in place on desktop - and are now not quite as lenient after all.

The fix is to -

• only add the 'im' adnames when we're actually able to inject an adslot, and
• rename lenientRules because their name is misleading

And now the zombie is gone, with the proper inline MPU in its place -

[paperboyo]

This is gonna be totally off-topic, but I just wanted to express sheer amazement at the way you thoroughly explain your PRs, @jbreckmckye! It's like having -verbose added to your username every time... One learns so much from you, thanks (or one could, would one understood a thing)!

[jbreckmckye]

@paperboyo - That is very kind of you to say! I'd always worried whether I was being a bit too verbose.

[uplne]

👍