How do I get Jest to catch the thrown error as expected?

Question

I am attempting to write some tests in Jest and keep getting the below result. How do I get Jest to catch the thrown error as expected? Code:

test("Test that TEXT_PROPERTIES can throw a typeError", () => {
  function testError() {
    try {
      throw new TypeError(`why doesn't this work`);
    } catch (e) {
      console.error(e);
    }
  }

  expect(() => {
    testError();
  }).toThrow();
});

Result:

  × Test that TEXT_PROPERTIES can throw a typeError (11 ms)

  ● Test that TEXT_PROPERTIES can throw a typeError

    expect(received).toThrow()

    Received function did not throw

      62 |   expect(() => {
      63 |     testError();
    > 64 |   }).toThrow();
         |      ^
      65 | });
      66 | 

      at Object.<anonymous> (tests/components/typography/typography.test.js:64:6)

  console.error
    TypeError: why doesn't this work

I have read a bunch of other "answers" to this question but none of them work.

Answer 1

testError does not throw an error to the outside world because of try-catch block. From the perspective of Jest's expect, testError returns undefined and not an exception (error). Here's a similar test:

 function testError() { try { throw new TypeError(`why doesn't this work`); } catch (e) { console.error(e); } } var result = testError(); console.log(result); // undefined console.log(result instanceof TypeError); // false

Change the function to this:

function testError() {
    throw new TypeError(`why doesn't this work`);
}

 function testError() { throw new TypeError(`why doesn't this work`); } // We want to use try-catch to encapsulate the error try { result(); } catch (e){ console.log(e); // undefined console.log(e instanceof TypeError); // false console.log(e instanceof TypeError); // false }