约束类型以具有特定类型的属性

Question

interface Person {id:number, name:string}


const someFunction(people: ???) => {...}

Question: Is it possible to typeguard people parameter to only accept an object with all properties as a Person. Such as:

people:{
   user1:{id:1,name:'user1'},
   user2:{id:1,name:'user2'},
   user3:{id:1,name:'user3'}
}

Answer 1

Record<Keys,Type>

You can leverage Record with string as key's type and Person as value's type.

interface Person {
  id: number,
  name: string,
}

const someFunction = (people: Record<string, Person>) => {
  // function logic here
};

someFunction({
  user1: { id: 1, name: 'user1' },
  user2: { id: 1, name: 'user2' },
  user3: { id: 1, name: 'user3' },
});

Answer 2

You can use index signatures :

interface Person {id:number, name:string}

const someFunction = (people: { [index:string]: Person }) => { /* ... */ }

someFunction({
   user1:{id:1,name:'user1'},
   user2:{id:1,name:'user2'},
   user3:{id:1,name:'user3'}
});

Answer 3

Based on the question a custom type with a dynamic key might be useful

interface Person {id:number, name:string}

type People = {
    [key:string]:Person;
}

const someFunction = (people:People ) => {...}

someFunction({"user1":{id:1,name:"name1"},"user2":{id:1,name:"name2"}})