Internally TS is a two pass compilation. First type check, then transpile to ES5. The type check step should be available to run on its own. IMO they should no

Internally TS is a two pass compilation. First type check, then transpile to ES5. The type check step should be available to run on its own. IMO they should not even worry about transpiling, just be a type checking engine. The API for TS, last I used it, was extremely limited. It has always been viewed as a black box compiler by the authors- they need to expose more flexibility.