I&#39;m struggling to work out the best way to verify that a promise is rejected in a Mocha test while using async/await.

Here&#39;s an example that works, but I dislike that `should.be.rejectedWith` returns a promise that needs to be returned from the test function to be evaluated properly. Using async/await removes this requirement for testing values (as I do for the result of `wins()` below), and I feel that it is likely that I will forget the return statement at some point, in which case the test will always pass.

    // Always succeeds
    function wins() {
      return new Promise(function(resolve, reject) {
        resolve(&#39;Winner&#39;);
      });
    }
    
    // Always fails with an error
    function fails() {
      return new Promise(function(resolve, reject) {
        reject(&#39;Contrived Error&#39;);
      });
    }
    
    it(&#39;throws an error&#39;, async () =&gt; {
      let r = await wins();
      r.should.equal(&#39;Winner&#39;);
    
      return fails().should.be.rejectedWith(&#39;Contrived Error&#39;);
    });

It feels like it should be possible to use the fact that async/await translates rejections to exceptions and combine that with Chai&#39;s should.throw, but I haven&#39;t been able to determine the correct syntax.

Ideally this would work, but does not seem to:

    it(&#39;throws an error&#39;, async () =&gt; {
      let r = await wins();
      r.should.equal(&#39;Winner&#39;);
    
      (await fails()).should.throw(Error);
    });

All Chai as-Promised Solutions on Gang of Coders

Total of 1 Chai as-Promised Solutions

Verify that an exception is thrown using Mocha / Chai and async/await