SebastianVerified account

When using Flow, be careful with empty objects. They are "unsealed" which means that all properties are effectively optional at the original call site. Meaning, this does NOT error: const obj: {foo: string} = {}; This behaviour is specific to an empty object.

So this will pass flow check but throw at runtime? type Foo = { baz: () => void } function callBaz(foo: Foo) { // baz exists because types return foo.baz() } const foo: Foo = {} callBaz(foo) > UNDEFINED IS NOT A FUNCTION

to answer your question tho:

I don’t think that should error. Will check.