为什么 Typescript 要求分配 Getter？

Question

Typescript prompts: 'is missing the following properties from type Test: testGetter'.

export interface ITest {
  id?: string | number;
  property: string;
}

export class Test implements ITest {
  id?: string | number;
  property: string;

  constructor(test?: Test) {
    Object.assign(this, test);
  }

  get testGetter() {
    return 1;
  }
}

Answer 1

Your interface declares the property as a string. However, you don't initialize it in the class so it's real type is string|undefined

Might be you misspelled the interface?

Initialize it and code should works

export interface ITest {
  id?: string | number;
  property: string;
}

export class Test implements ITest {
  id?: string | number;
  property: string = '';

  constructor(test?: ITest) {
    Object.assign(this, test);
  }

  get testGetter() {
    return 1;
  }
}

new Test(new Test()) //compiles
new Test({ id: '1', property: '2' }) //compiles