Background
(Per a discussion yesterday with @Jdlrobson and @Groceryheist:)
The ReadingDepth schema should not send events for user actions that are not considered page views - in particular, edits and action pages like action=history URLs should be excluded.
Special pages (namespace -1) can be left as is. (There is some value in having data for them too, which outweighs consistency with the pageview definition in this case - the pageview definition FAQ about this is a bit ambiguous and not entirely correct anyway.)
Developer notes
Currently ReadingDepth does not check the value of wgAction meaning ReadingDepth events are sent on https://en.wikipedia.org/wiki/Spain?action=edit, https://en.wikipedia.org/wiki/Spain?action=history etc..
A conditional should be added to prohibit this.
QA steps
ReadingDepth is enabled for 100% of users on Reading web staging
- Verify no reading depth event is loaded on https://reading-web-staging.wmflabs.org/wiki/Main_Page?action=edit for both desktop and mobile
- Verify no reading depth event is loaded on https://reading-web-staging.wmflabs.org/wiki/Main_Page?action=history for both desktop and mobile
- Verify a reading depth event is sent on https://reading-web-staging.wmflabs.org/wiki/Main_Page for both desktop and mobile