A spiritual successor to komodo, Omo is a TypeScript type-checker. Omo is far from supporting all of TypeScript, but it supports a useful subset of it including custom type definitions, discriminated unions, and classes.
Run cargo run -- <file> to run Omo on a file. For example, the following will print out a type annotated version of the file test/test.ts:
$ cargo run -- test/test.ts