Need inputs on mocking "useDefaultApiClient" in jest test cases for React

[himan085]

Hi, the generated code by PDK provides a method useDefaultApiClient for making authenticated calls using SigV4. I need some inputs on understanding how to mock this method for my test cases using Jest in React.
There are 2 versions of mocking that I have experimented with:

Version 1:

const mockCreateApi = jest.fn();

jest.mock("../../../../hooks/use-default-api-client", () => ({
  useDefaultApiClient: () => {
    return {
      create: mockCreateApi,
    };
  },
}));

it("successfully renders", () => {
  mockCreateApi.mockResolvedValue("success"); // resolving value inside test case
  ...
});

---

Version 2:

const mockClient = {
  create: () => {
    return Promise.resolve("success");
  },
};

jest.mock("../../../../hooks/use-default-api-client", () => ({
  useDefaultApiClient: () => mockClient,
}));

it("successfully renders", () => {
  // test cases always resolve to "success" as specified by the mockClient
  ...
});

I'm mostly using version 1 across my code base. For one my specific source codes, the jest test cases are getting stuck with no termination. I tried to wait around 10mins but the tests were simply stuck, not even timing out. However when I changed the mock to use version 2 the test cases worked as expected. The source code in the browser is also working as expected.

Note: I verified there aren't any infinite loops by logging in both test cases and in the browser console.

I need some inputs on what might be going wrong here ? Any help is appreciated, thanks!
Let me know if more inputs or the source code is also required.

[cogwirrel]

Hi Himanshu, thanks for reaching out!

I'm afraid I'm not sure why you'd be experiencing tests hanging with version 1 and not version 2 - it's hard to tell without the full codebase (and I am certainly not a jest expert!). Both of the methods look ok to me!

One possibility is that the hook is being invoked outside of your test somehow, so you need to provide a mock resolved value to begin with? You could try adding mockCreateApi.mockResolvedValue("success"); to just after where mockCreateApi is declared?

Sorry to not be of more help!

Thanks,
Jack