I'm trying to spy on a function that come from uuidv4 package but I didn't figure out how to do that.
This is my User Class:
import { uuid } from 'uuidv4';
import { IUser } from '../interfaces/IUser';
export class User implements IUser {
constructor(
public name: string,
public email: string,
public password: string,
public id?: string,
) {
this.id = id ? id : uuid();
}
}
What I'm trying to do is spy on that uuid() method that is called on the constructor of the User.ts. I tried something like this:
import { User } from './User';
describe('User', () => {
it('should call uuid() when no id is provided', () => {
const sut = new User('Foo', '[email protected]', '12345');
const spy = jest.spyOn(sut, 'uuid');
expect(spy).toHaveBeenCalledTimes(1);
});
});
But it didn't work. Anyone knows how could I do this?
CodePudding user response:
You don't need to mock or install spy on the uuid
to test the implementation detail. You can test the with Using a regular expression to check user.id
is a UUID v4 or not.
Using a regular expression:
If you want to perform the verification on your own using a regular expression, use the regex property, and access its v4 or v5 property
index.ts
:
import { uuid } from 'uuidv4';
interface IUser {
id?: string;
}
export class User implements IUser {
constructor(public name: string, public email: string, public password: string, public id?: string) {
this.id = id ? id : uuid();
}
}
index.test.ts
:
import { User } from './';
import { regex } from 'uuidv4';
describe('User', () => {
it('should call uuid() when no id is provided', () => {
const user = new User('Foo', '[email protected]', '12345');
expect(regex.v4.test(user.id!)).toBeTruthy();
});
});
PASS stackoverflow/72130740/index.test.ts (13.885 s)
User
✓ should call uuid() when no id is provided (2 ms)
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 16.53 s
Also take a look at the uuid
test case