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mocha/chai: assert thrown error

You want to test a function which trhwos an error. But you can not catch that function inside the chai assertions.

One way to fix this is to wrap your function inside an anonymous function.

---

class SystemUnderTest {

    run() {
        throw new Error('I always puke!');
    }
}

module.exports = SystemUnderTest;

---

const SUT = require('../../utils/test.js');

...

it('catching thrown errors', () => {
    let sut = new SUT();

    // expect(sut.run()).to.throw(); // FAILS

    expect(() => sut.run()).to.throw(); // PASS
});

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