satisfies.ts

const foo = {
    a: 255,
    b: 255,
    c: 255,
    // ❌ We get the error Type 'string' is not assignable to type 'number'
    d: 'bar'
} satisfies Record<string, number>;

// ✅ We are not loosing any type inferance information
// typeof foo is 
// const foo: {
//    a: number;
//    b: number;
//    c: number;
//    d: string;
// }