Mocking

Introduction

Request Mocking is a feature that allows for stubbing/mocking the response for a given endpoint, keeping the complete request lifecycle and events.

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Initialization

You can mock the response via the request setMock method:

const mockedRequest = request.setMock({ data: { test: 1, array: [200, 300, 404] } });

This way, the mockedRequest will always return the data with value { test: 1, array: [200, 300, 404] } }.

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Config

setMock method accepts also the config object, that allows for tweaking our response.

    const request = client
      .createRequest()({ endpoint: "shared-base-endpoint" })
      .setMock({
        data: {mocking: 'is fun'},
        config: {
          responseDelay: 1500,
          status: 200
        },
      });

• status - setting the response status - it may be number or string - default: 200
• success - informs whether the request should be as successful or not - default: true
• responseDelay - number of milliseconds the response should be delayed for.
• requestSentDuration and responseReceivedDuration - two variables that indicate how long request/response phase should take (in milliseconds). If combined take longer than provided timeout, each values will be automatically adjusted to last half the timeout time.

Usage and use cases

Mocker can be used in a few ways.

1. It can accept an object (as presented above):

const mockedRequest = request.setMock({ data: { test: 1, array: [200, 300, 404] } });  // Always returns data: { test: 1, array: [200, 300, 404]

2. It can accept an array of values. In this case - values will be iterated over cyclically and applied each time a request is executed.

  request.setMock([
    { data: { data: [1, 2, 3] }, config: { status: 400, success: false } },
    { data: { data: [1, 2, 3] }, config: { status: 200 } },
  ]);

await request.send() // returns  { data: { data: [1, 2, 3] }, config: { status: 400, success: false } }
await request.send() // returns  { data: { data: [1, 2, 3] }, config: { status: 200 } }
await request.send() // returns  { data: { data: [1, 2, 3] }, config: { status: 400, success: false } }

3. It also accepts method that has access to the request itself. This allows for dynamic mocking, dependent on the passed arguments during execution.

    const mockedRequest = client
      .createRequest()({ endpoint: "/users/:id" })
      .setMock((r) => {
        const { params } = r;
        if (params.id === 11) {
          return { data: [1, 2, 3], config: { status: 222 } };
        }
        return { data: [4, 5, 6] };
      });

4. The passed method may be asynchronous:

    const mockedRequest = client
      .createRequest<Record<string, any>>()({ endpoint: "users/:id" })
      .setMock(async (r) => {
        if (r?.params?.id === 1) {
          return { data: [1, 2, 3], config: { status: 222 } };
        }
        return { data: [4, 5, 6] };
      });

It is also possible to pass a list of functions - the mocker will cycle over them and execute the correct one each time a request is executed.

Removal

If, for any reason, user needs to remove mocker from request, it is possible to be done via removeMock method.

mockedRequest.removeMock();