Reusable type annotation for function declaration in Typescript?

Issue

type Func = (foo:string) => void

// function expression
const myFunctionExpression:Func = function(foo) {
  console.log(foo)
}

In the Typescript snippet above, I am using type alias to annotate the variable in a function expression.

The type alias:

type Func = (foo:string) => void

is reusable in another function expression to reduce repetition.

My question is: Is there a way to reuse this type alias to annotate a function declaration ?

// function declaration
function myFunctionDeclaration(foo:string):void {
  console.log(foo)
}

After some search online, I cannot seem to find such syntax, what am I missing?

Thanks

update:

At the time of this writing there is a ticket on github requesting for this feature: Suggestion: Type annotations and interfaces for function declarations #22063 (thanks to comment from @jcalz)

Solution

At time of writing (TypeScript 3.4), there is not a way to apply a type to a function declaration.

Answered By - Ryan Cavanaugh