no-return-from-async.md

Disallow returning from an async test or hook (mocha/no-return-from-async)

🚫 This rule is disabled in the ✅ recommended config.

Mocha's tests or hooks (like before) may be asynchronous by returning a Promise. When such a Promise-returning function is defined using an ES7 async function it can be confusing when combined with an explicit return of a Promise, as it's mixing the two styles.

Rule Details

This rule looks for every test and hook (before, after, beforeEach and afterEach) and reports when the function is async and returns a value. Returning a non-Promise value is fine from Mocha's perspective, though it is ignored, but helps the linter catch more error cases.

The following patterns are considered warnings:

describe('suite', function () {
    before('title', async function () {
        return foo;
    });

    it('title', async function () {
        return bar().then(function () {
            quux();
        });
    });
});

These patterns would not be considered warnings:

describe('suite', function () {
    before('title', async function () {
        await foo();
    });

    it('title', function () {
        if (bailEarly) {
            return;
        }
        await bar();
    });
});

When Not To Use It

• If you use another library which exposes a similar API as mocha (e.g. before, after), you should turn this rule off, because it would raise warnings.