Develop a simulated version that does not include all the functionalities of the primary service

Question

Develop a simulated version that does not include all the functionalities of the primary service

Let's imagine a scenario where there is an OriginalService class with various methods

class OriginalService {

  method1() { }
  method2() { }
  method3() { }
.. 
}

Now, suppose we need to create a mock of OriginalService that will only be used with method1.

If we try the following approach, TypeScript will flag missing methods on mockService

let mockService: OriginalService;
mockService = {
  method1() {
  }

Is there a way to declare mockService as OriginalService without explicitly listing all of OriginalService's properties?

angular typescript

Answer 1

Answer №1

Extend the OriginalService class like this:

class CustomService extends OriginalService {
   method2() {
      // overriding this method!
  }
}

let customService = new CustomService();
this.customService.method2();

Refer to this handy documentation: https://www.typescriptlang.org/docs/handbook/classes.html

Wishing you the best of luck with your coding endeavors!

Answer 2

Extend the OriginalService class like this:

class CustomService extends OriginalService {
   method2() {
      // overriding this method!
  }
}

let customService = new CustomService();
this.customService.method2();

Refer to this handy documentation: https://www.typescriptlang.org/docs/handbook/classes.html

Wishing you the best of luck with your coding endeavors!

Answer 3

Answer №2

To create a more manageable way of mocking, consider defining an interface that only includes the methods you plan to mock.

interface Service {
    method1();
}

let realService: Service;
let mockService: Service;

realService = new RealService();
mockService = {
    method1() {
        ...
    }
}

By adhering to the interface, you only need to focus on the specific method being called.

function test(svc: Service) {
    svc.method1();
}

Additionally, you can define multiple interfaces for each mock scenario, while the real service can implement them all.

Answer 4

To create a more manageable way of mocking, consider defining an interface that only includes the methods you plan to mock.

interface Service {
    method1();
}

let realService: Service;
let mockService: Service;

realService = new RealService();
mockService = {
    method1() {
        ...
    }
}

By adhering to the interface, you only need to focus on the specific method being called.

function test(svc: Service) {
    svc.method1();
}

Additionally, you can define multiple interfaces for each mock scenario, while the real service can implement them all.

Develop a simulated version that does not include all the functionalities of the primary service

Answer №1

Answer №2

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