Using Partial to make all properties of an object type optional

You need a version of your object type where all the properties are optional but don’t want to write a duplicate type and maintain both copies

• Use the Partial<Type> utility type
• TS docs: “Constructs a type with all properties of Type set to optional. This utility will return a type that represents all subsets of a given type.”

Create a new type that’s defined as your original type wrapped in Partial<>:

type Original = {
  foo: string
}
 
type Optional = Partial<Original>

That’s it. 🙂

Now, when you use the Optional type, you’ll see that property foo is now string | undefined instead of string:

// add usage example

• Partial<Type> | TypeScript docs
• Make all properties optional in TypeScript | Borislav Hadzhiev
• Make all properties within a Typescript interface optional | StackOverflow
• Optional Properties | TypeScript docs

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