UPDATE: This question was closed with a link to this question, but note that the linked page has no accepted answers.
I have the following mocha test:
import 'mocha';
import { expect } from 'chai';
describe('simple test', () => {
const functionWithError = async () => {
throw new Error('abc');
};
it('should work in a regular function', () => {
const execute = () => functionWithError();
expect(execute).to.throw(Error, 'abc');
});
it('might work in an async function?', () => {
const execute = async () => await functionWithError();
expect(execute).to.throw(Error, 'abc');
});
});
When I run this, I expect everything to pass, but I get instead:
% npm run test
> functions@ test /home/me/repos/exception-tests
> mocha -r ts-node/register test/**/*.spec.ts
simple test
1) should work in a regular function
(node:2997) UnhandledPromiseRejectionWarning: Error: abc
at functionWithError (/home/me/repos/exception-tests/test/confused.spec.ts:6:11)
at execute (/home/me/repos/exception-tests/test/confused.spec.ts:10:27)
at Proxy.assertThrows (/home/me/repos/exception-tests/node_modules/chai/lib/chai/core/assertions.js:2630:7)
at Proxy.methodWrapper (/home/me/repos/exception-tests/node_modules/chai/lib/chai/utils/addMethod.js:57:25)
at Context.it (/home/me/repos/exception-tests/test/confused.spec.ts:11:29)
at callFn (/home/me/repos/exception-tests/node_modules/mocha/lib/runnable.js:358:21)
at Test.Runnable.run (/home/me/repos/exception-tests/node_modules/mocha/lib/runnable.js:346:5)
at Runner.runTest (/home/me/repos/exception-tests/node_modules/mocha/lib/runner.js:621:10)
at /home/me/repos/exception-tests/node_modules/mocha/lib/runner.js:745:12
at next (/home/me/repos/exception-tests/node_modules/mocha/lib/runner.js:538:14)
at /home/me/repos/exception-tests/node_modules/mocha/lib/runner.js:548:7
at next (/home/me/repos/exception-tests/node_modules/mocha/lib/runner.js:430:14)
at Immediate.<anonymous> (/home/me/repos/exception-tests/node_modules/mocha/lib/runner.js:516:5)
at runCallback (timers.js:705:18)
at tryOnImmediate (timers.js:676:5)
at processImmediate (timers.js:658:5)
(node:2997) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)
(node:2997) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.
2) might work in an async function?
(node:2997) UnhandledPromiseRejectionWarning: Error: abc
at functionWithError (/home/me/repos/exception-tests/test/confused.spec.ts:6:11)
at execute (/home/me/repos/exception-tests/test/confused.spec.ts:15:39)
at Proxy.assertThrows (/home/me/repos/exception-tests/node_modules/chai/lib/chai/core/assertions.js:2630:7)
at Proxy.methodWrapper (/home/me/repos/exception-tests/node_modules/chai/lib/chai/utils/addMethod.js:57:25)
at Context.it (/home/me/repos/exception-tests/test/confused.spec.ts:16:29)
at callFn (/home/me/repos/exception-tests/node_modules/mocha/lib/runnable.js:358:21)
at Test.Runnable.run (/home/me/repos/exception-tests/node_modules/mocha/lib/runnable.js:346:5)
at Runner.runTest (/home/me/repos/exception-tests/node_modules/mocha/lib/runner.js:621:10)
at /home/me/repos/exception-tests/node_modules/mocha/lib/runner.js:745:12
at next (/home/me/repos/exception-tests/node_modules/mocha/lib/runner.js:538:14)
at /home/me/repos/exception-tests/node_modules/mocha/lib/runner.js:548:7
at next (/home/me/repos/exception-tests/node_modules/mocha/lib/runner.js:430:14)
at Immediate.<anonymous> (/home/me/repos/exception-tests/node_modules/mocha/lib/runner.js:516:5)
at runCallback (timers.js:705:18)
at tryOnImmediate (timers.js:676:5)
at processImmediate (timers.js:658:5)
(node:2997) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 3)
0 passing (15ms)
2 failing
1) simple test
should work in a regular function:
AssertionError: expected [Function: execute] to throw Error
at Context.it (test/confused.spec.ts:11:29)
2) simple test
might work in an async function?:
AssertionError: expected [Function: execute] to throw Error
at Context.it (test/confused.spec.ts:16:29)
npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! functions@ test: `mocha -r ts-node/register test/**/*.spec.ts`
npm ERR! Exit status 2
npm ERR!
npm ERR! Failed at the functions@ test script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /home/me/.npm/_logs/2020-11-19T02_45_43_745Z-debug.log
The differences between async and regular functions in JavaScript confuses me somewhat... What do I change in this file to get a passing test when the called async function (functionWithError()) throws.
