New feature: Rule testing

When creating new rules or editing existing ones, it's now possible to test rules against existing items. Lighthouse lists existing items in your account, and shows which items the rule would've applied to.

This makes it much easier to verify that rules are doing what you want them to do.

When editing a rule, there's now an additional Test rule tab. In this case I created a rule that automatically dismisses all items tagged with news and have trump in the title.

When going to the new Test rule tab, the rule is tested against all items that were added in the past 10 weeks. Using such a large timeframe ensures that even rules that apply only to a few items are still adequately tested.

The next tab shows all matched items. By checking the list you can make sure that the rule only applies to items you want, and doesn't have unintended consequences.

In the Explore tab you can check the rule against all items in your account. Items that match the rule have a green background, the others a red one.

It's also possible to add filters in the Explore tab to only show a subset of items. In this case for example I filtered by the tag news, which makes it easier for me to find items the rule will apply to. And that helps a lot with creating rules that match the items the rule is intended to match.