>>> My Info: Win7_64, Nightly 49, 32bit, ID 20160526082509 STR_1: (chrome://) 1. Open about:home or about:newtab 2. Open debugger 3. Prettify script "contentSearchUI.js" STR_2: (resource://) 1. Open about:debugging 2. Open debugger 3. Prettify script "react.js" STR_3: (scripts in extensions) 1. Open about:debugging 2. Enable "Enable add-on debugging", click "Debug" near Pocket extension 3. Prettify script "bootstrap.js" AR: No visible action ER: Either X or Y X) Said scripts should be prettified Y) UI should indicate that those scripts can't be prettified, e.g. don't display pretty-print buttons

User Agent Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:53.0) Gecko/20100101 Firefox/53.0 Build ID 20170115030210 I was able to reproduce STR_1 and STR_2 on Nightly 49.0a1, but not on the latest Nightly (53.0a1). As such I ran mozregression with --find-fix and it seems the two scenarios we're fixed by Bug 1313961. STR_3 however is still reproducible on the latest Nightly.

When I do this, indeed nothing happens. However, that seems correct to me, because the original sources are already "pretty". So I wouldn't expect anything to happen. I think disabling the prettify button in this case is most likely not done because it would be expensive to compute: about as expensive as prettifying in the first place. I'm somewhat inclined to wontfix this, but I'm leaving it open on the chance that I've misunderstood the STR.