CODEWITHSUNDEEP
unit-testingjestjsnestjshttpexception
Johnny
Johnny

Reputation: 291

Jest "Matcher error: expected value must be a function"

I'm using NestJS with Jest and I get this error:

Matcher error: expected value must be a function

... when run following unit test.

I have set invalid email in mockBody. Did I missed anything here?

app.service.ts

@Injectable()
export class UserService {
  constructor(private emailService: EmailService) {}

  async registerUserInquiry(user: UserDto): Promise<{ email: string }> {
    try {
      await sendEmail(user);
    } catch (error) {
      throw new HttpException('Something went wrong!', HttpStatus.BAD_REQUEST);
    }
    return {
      email: user.email,
    };
  }
}

app.service.spec.ts

describe("registerUser()", () => {
  it("Should throw bad request error when passing invalid data", async () => {
    const mockBody: UserDto = {
      name: "John Doe",
      message: "Example inquiry message",
      email: "@example",
      mobile: "+60121234567",
    };

    expect(async () => await service.registerUserInquiry(mockBody)).toThrow(
      new HttpException("Something went wrong!", HttpStatus.BAD_REQUEST)
    );
  });
});

email.config.ts

export const sendEmail = async (user: User) => {
  const transporter = nodemailer.createTransport({
    ... // service & auth
  });

  const options = {
   ... // email info
  };

  await transporter.sendMail(options, function (error, info) {
    try {
      console.info(error);
      return info;
    } catch (error) {
      console.error(error);
      throw error;
    }
  });
};

Error:

enter image description here

Upvotes: 1

Views: 3053

Answers (2)

Artem Aleksieiev
Artem Aleksieiev

Reputation: 31

try {
    await service.registerUserInquiry(mockBody)
} catch(err) {
expect(err).toBeInstanceOf(BAD_REQUEST);
expect(err.message).toEqual{'Something went wrong!'}
}

Upvotes: 0

n1md7
n1md7

Reputation: 3451

Instead of this

expect(async () => await service.registerUserInquiry(mockBody)).toThrow(
  new HttpException("Something went wrong!", HttpStatus.BAD_REQUEST)
);

Try this one

await expect(service.registerUserInquiry(mockBody)).rejects.toThrowError(...)

Your function is a promise which means it is not throwing an error but instead it rejects.

Upvotes: 3

Related Questions