如何在块生效之前在mocha中获取断言？

Question

How to get asserts in mocha before blocks to work? If I am not suppose to do this let me know. Currently, using promises, if I get an error using an catch block, I'll add an assert to fail the before block. WHat I want is it to fail the describe block, but instead I get two possible outcomes. 1. My test suite completely crashes, 2. I have to wait for each timeout to hit for each test because the before block failed.

before(function (done) {
    promise()
        .then(function () {
            done();
        })
        .catch(function (error) {
            assert(!error);
            done();
        });
});

I even tried this, thinking, maybe the done was never called.

before(function (done) {
    promise()
        .then(function () {
            //no done here
        })
        .catch(function (error) {
            assert(!error);
        });
        .finally(function () {
            done();
        });
});

So far to avoid crashing and waiting, and to make it work, I have done this:

var beforeError;
before(function (done) {
    promise()
        .then(function () {
            done();
        })
        .catch(function (error) {
            beforeError = error;
            done();
        });
});

it('test something', function () {
    assert(beforeError, 'Before block failed with error.');
});

I am really curious if there is a better way to go about this so that if my before/beforeEach/after/afterEach blocks fail, it doesn't cause me to wait ages or my suite to crash! Thanks S/O community! :)

Answer 1

I can't speak to your use of the done callback, but mocha 3.0 supports promises in before hooks now. Were I to write this, I would let the returned promise throw its own error, which will fail the before hook without breaking the suite.

before(function () {
    return promise(<async behavior here>);
});