Axios mock adapter returns 404 on all reqeusts

Question

When trying to setup axios to mock requests to an incomplete api server I'm using to build a front end, I am getting 404 responses on all requests, even those that aren't mocked at all.

const api = axios.create({
  baseURL: "https://jsonplaceholder.typicode.com/"
});
const mock = new MockAdapter(api);

// setup the mock url
mock.onGet("/test", ({ url }) => {
  console.log(url);
  return import(`./mocks/${url}.json`);
});

async function testMock() {
  try {
    const shouldBeMocked = await api.get("/test");
    console.log(shouldBeMocked);
  } catch (err) {
    console.log("this should have been mocked");
    console.log(err);
  }
  try {
    const isRealURL = await api.get("/json/1");
    console.log(isRealURL);
  } catch (err) {
    console.log("this should have fetched from the api");
    console.log(err);
  }
  try {
    const isRealURLWithFetch = await fetch(
      "https://jsonplaceholder.typicode.com/json/1"
    );
    const data = await isRealURLWithFetch.text();
    console.log(data);
  } catch (err) {
    console.log("this won't be logged");
    console.log(err);
  }
}

Codesandbox Example

Answer 1

You didn't use axios-mock-adapter correctly, here is the signature of mock.onGet() method for "axios-mock-adapter": "^1.19.0".

type RequestMatcherFunc = (
  matcher?: string | RegExp,
  body?: string | AsymmetricRequestDataMatcher,
  headers?: AsymmetricHeadersMatcher
) => RequestHandler;

As you can see, the second parameter is NOT the "reply" function. You should pass the function to the reply method.

mock.onGet("/test").reply(async ({ url }) => {
  console.log(url);
  return [200, await import(`./mocks/${url}.json`)];
});