fallback for the entire typescript interface?

Question

I know we can set optional property using ? in interface but how to make the entire interface fallback to null or emtpy object?

interface MyType {
   abc: string
   def?: number
}

I tried

interface MyType {
   abc: string
   def?: number
} | {}

but now luck.

Answer 1

I'd find the easiest way is to not pollute the type more than necessary and have a fallback as eg:

var MyObject: MyType | {} | undefined;

// Then it can take
MyObject = {};
MyObject = undefined;
MyObject = {abc:"abc"}
MyObject = {abc:"abc", def:1}

Answer 2

You can use the Partial type

https://www.typescriptlang.org/docs/handbook/utility-types.html#partialt

interface MyType {
 abc: string
 def?: number
}

const obj: Partial<MyType> = {}