I am writing a language plugin. Among the features I implemented are:
(1) A FindUsagesHandler.
(2) References, which are returned on usage points, and resolve to the definition.
With these, I get the following features:
(3) All definition and usages are highlighted when the cursor is either on a definition or a usage
(4) Ctrl-click on a usage goes to the definition.
Amazingly, it looks like I also got another feature for free without any extra effort:
(5) Ctrl-click on a definition goes to its usage (when unique), or shows a combo with a list of usages to chose from. All that even though I did NOT implement a FindUsageProvider, which is great!
However, I recently rewrote my implementation of (1) and (2), and I can see that (3) and (4) are still 100% working, but (5) stopped working (it always shows "No usage found in project file" while correctly highlighting those usages). As it was not documented, and I didn't do anything to make it work in the first place, I don't know what I broke. How is (5) working exactly when it's based on (1) and (2)? What should I look at to get it back?