Seeking Pattern Matching Solution for Union Type in TypeScript

type Foobar =
  | {
      foo: 'blah'
    }
  | {
      bar: 'bla blah'
    }
const thing: Foobar = generateThing()
Match.value(thing).pipe(
  Match.keyExists('foo'), () => doStuffs()),
  Match.exhaustive
)