How can I get mocha to fail on exceptions?

test-with-error.js

describe('this should cause tests to fail', function(){
    // this will cause an exception
    // causing mocha to ignore this whole file
    var hello = JSON.parse('{"hello":}');
    
    it('should something', function(){
        // magic
        assert.equal(true, true);
    })
});

With vanilla Mocha, this works as expected. With mocha + karma + karma-webpack + webpack, it doesn't.