Szybki TS - ćwiczenie 2

Proste ćwiczenie z mapped types i capitalize. Kontynuacja lekcji poprzednich. Do dzieła.

Ok, przypomnijmy sobie ten interfejs:

interface Employee2 {
    id: number;
    name: string;
    age: number;
    salary: number;
}

A teraz te typy, ja już nie podpowiadam co one robią:

type CapitalizeKeys<T> = {
    [P in keyof T as `${Capitalize<string & P>}`]: T[P];
  };

type Getter<T> = {
    [P in keyof T as `get${Capitalize<string & P>}`]: () => T[P]
  };

type Setter<T> = {
    [P in keyof T as `set${Capitalize<string & P>}`]: (newVal: T[P]) => boolean
  };

type WithGetters<T> = {
    [P in keyof T]: T[P];
} & {
    [P in keyof T as `get${Capitalize<string & P>}`]: () => T[P]
  };

type WithGetterSetters<T> = {
    [P in keyof T]: T[P];
} & {
    [P in keyof T as `get${Capitalize<string & P>}`]: () => T[P]
  } & {
    [P in keyof T as `set${Capitalize<string & P>}`]: (newVal: T[P]) => boolean
  };

Ok, to teraz taki typ:

type Listeners<T> = {
    [P in keyof T as `on${Capitalize<string & P>}Change`]: (newValue: T[P]) => void; 
}

type EmpListeners = Listeners<Employee2>

Mam nadzieję, że dobrze zgadliśmy:

type Listeners<T> = {
    [P in keyof T as `on${Capitalize<string & P>}Change`]: (newValue: T[P]) => void; 
}

type EmpListeners = Listeners<Employee2>

// type EmpListeners = {
//     onIdChange: (newValue: number) => void;
//     onNameChange: (newValue: string) => void;
//     onAgeChange: (newValue: number) => void;
//     onSalaryChange: (newValue: number) => void;
// }

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Szybki TS – ćwiczenie 2