When we first created the release issue, the thinking was that we wanted to launch support for those two languages at the same time, and for that support to be compatible with each other. (So we could correctly follow e.g. a TS library referencing a definition in an upstream JS library.)
Unfortunately we never got JS support to the point where we could GA it. Largely for scaling reasons — there is a HUGE amount of JS on GitHub, and JS is a dynamic enough language that we have to do more per-file processing on it than for TS or Python. We decided not to wait for JS to be GA-ready before releasing TS, but then never corrected the release issue to account for that.
We had conflated JS and TS support into a single release issue. JS support never landed, but TS did: https://github.blog/changelog/2024-03-14-precise-code-naviga...
When we first created the release issue, the thinking was that we wanted to launch support for those two languages at the same time, and for that support to be compatible with each other. (So we could correctly follow e.g. a TS library referencing a definition in an upstream JS library.)
Unfortunately we never got JS support to the point where we could GA it. Largely for scaling reasons — there is a HUGE amount of JS on GitHub, and JS is a dynamic enough language that we have to do more per-file processing on it than for TS or Python. We decided not to wait for JS to be GA-ready before releasing TS, but then never corrected the release issue to account for that.