Incorrect custom async matcher error message

🐛 Bug Report

Custom async matchers are throwing with an error message prefixed with Error and not showing the source code of where the error originated from.

To Reproduce

Given the example in the docs, I get the following output:

expect.extend({
  async toBeDivisibleByExternalValue(received) {
    const externalValue = await Promise.resolve(1000);
    const pass = received % externalValue == 0;
    if (pass) {
      return {
        message: () =>
          `expected ${received} not to be divisible by ${externalValue}`,
        pass: true,
      };
    } else {
      return {
        message: () =>
          `expected ${received} to be divisible by ${externalValue}`,
        pass: false,
      };
    }
  },
});

test('is divisible by external value', async () => {
  await expect(100).toBeDivisibleByExternalValue();
  await expect(101).not.toBeDivisibleByExternalValue();
});

Expected behaviour

A pointer to the source and the message highlighted correctly.

[theotherdon]

@SimenB Yes, I was able to make it work. I just have a couple of failing snapshots to update. I’m hoping to have the PR today or tomorrow.

[theotherdon]

@SimenB Thanks for the recommendation! 🙂 I just opened PR #7652 and also kept the refactoring to a minimum. (I’ll open a separate PR for the refactor once we merge this one.) I left a question for you regarding removing a couple of lines from the stack trace.