I did find this one: https://github.com/tenta-browser/tenta-dns/blob/master/src/t...
That's an internal test, meaning it has access to the package internals. A better test would test from outside the boundaries of the package to only interact with exposed symbols.
I would just caution people against doing direct comparisons of unit test suites between Ruby/Python and Go projects, because a lot of Ruby/Python testing really just mitigates deficiencies in those languages, and those deficiencies have created a sort of culture of exuberant, creative testing that isn't present in other languages.
Tests are good! Everything should have tests.
It looks to me more like compile-to-JS languages are winning this race. Which is good, as it enables sthings like ClojureScript and Elm. Also many of us think the lack of static types is the least of the problems in JS.
edit: Seems the TS tools also have JS linting functionality, where you put JSDoc annotations in comments and use the new --checkJs options, I guess you may have meant this too.