Why does the test expressed with eventually pass? I'm obviously missing something in the syntax or use case.
const chai = require('chai')
const chaiAsPromised = require("chai-as-promised");
chai.use(chaiAsPromised);
const {expect} = chai
function p() {
return new Promise( (resolve) => {
setTimeout( () => {
resolve(10);
},5000);
})
}
describe('Chai Eventually test', () => {
it('should fail!', () => {
expect(p()).to.eventually.equal(5)
});
it('should also fail!', async () => {
expect(await p()).to.equal(5)
});
})
running it with mocha I get:
Chai Eventually test
✔ should fail!
1) should also fail!
1 passing (2s)
1 failing
1) Chai Eventually test
should also fail!:
AssertionError: expected 10 to equal 5
+ expected - actual
-10
+5
at Context.<anonymous> (chaiError.js:19:26)
1 passing (4ms)
This happens immediately so it is not waiting for the promise to resolve.
You have a couple options here.
The simplest is to just return the expect:
it('should fail!', () => {
return expect(p()).to.eventually.equal(5); // <-- return this expectation
});
Alternatively, you can skip the return and use a done callback passed into chai's .notify method:
it('should fail using done!', (done) => { // <-- pass done into spec function
expect(p()).to.eventually.equal(5).notify(done); // <-- pass done to .notify()
});
And here's a StackBlitz showing it working correctly (i.e., failing) with those changes.