✅ Mock options in test

[orimdominic]

Hello @RobinTail,

I must say that I am impressed by the developer experience that this library provides. Oh! I wish that this was Express itself.
I have also gone through pull requests and issues and oh my! Your work rate on this is amazing. I appreciate that!

I would like to know if we can create a mock for the options object that is passed to a request handler in tests, the same way we can for request and logger using requestProps and loggerProps respectively.

A use case will be for a handler that attaches a method to options that sends emails, but during tests, we want this method to be mocked to avoid making requests to the mailing server. Let me show you what I mean in code:

We have this endpoint:

export const sendEmailEndpoint = defaultEndpointsFactory
  .addOptions({
    sendMail: (email: string, content: string) =>
      console.info(`sending ${content} to ${email}`),
  })
  .build({
    method: "post",
    input: z.object({
      email: z.string(),
    }),
    output: z.object({
      message: z.string(),
    }),
    handler: async ({ input, options, logger }) => {
      options.sendMail(input.email, "Lorem ipsum");
      return { message: `Email sent successfully` };
    },
  });

We test it

describe("sendEmailEndpoint", () => {
  it("should respond successfully", async () => {
    const testEmail = "[email protected]"
    const { responseMock, optionsMock } = await testEndpoint({
      endpoint: sendEmailEndpoint,,
      optionsProps: {
        sendEmail: jest.fn()
      },
      requestProps: {
        method: "POST",
        body: {
          email: testEmail
        },
      },
    });
    expect(optionsMock.sendMail).toBeCalledWith(testEmail, "Lorem ipsum");
    expect(responseMock.status).toBeCalledWith(200);
    expect(responseMock.json).toBeCalledWith({
      status: "success",
      data: { message: `Email sent successfully` },
    });
  });
});

We can also mock options.sendMail to reject or throw in separate test and then test that an error message and an error status code were returned.

Is there any way we can make this work? I am willing to collaborate to see it come to life.

[RobinTail]

Hello @orimdominic ,

thank you for appreciating the efforts of me and contributors.

In order to achieve your desire of mocking the email sending function,
You need to keep that function in a separate module (another file).

In your test, before importing the endpoint, you should mock the module containing that function.

Please refer to Jest documentation on own modules mocking:

https://jestjs.io/docs/manual-mocks#mocking-user-modules

And StackOverflow.

Use the jest.mock() method.

Without __mocks__ dir it should be similar to following:

const sendMail = jest.fn();
jest.mock('./mailUtil', () => ({ sendMail }));

import { myEndpoint } from './endpoint';

// in test:

expect(sendMail).toHaveBeenCalledWith();

Something like that.
I hope this information will help you.

[orimdominic]

Yes it does.
Thank you.

[RobinTail]

🚀 The whole thing about testEndpoint was simplified in the recently released v20, @orimdominic
No mocking required anymore.

[orimdominic]

Thanks for this. I'll look into it 💪

[RobinTail]

@orimdominic , there is now testMiddleware available for convenience