Dynamically Running Mocha Tests

I'm trying to run a series of tests dynamically. I have the following setup but it doesn't seem to run and I'm not getting any errors:

import Mocha from 'mocha';
const Test = Mocha.Test;
const Suite = Mocha.Suite;
const mocha = new Mocha();
for (let s in tests) {
  let suite = Suite.create(mocha.suite, s);
  tests[s].forEach((test) => {
    console.log('add test', test.name)
    suite.addTest(new Test(test.name), () => {
      expect(1+1).to.equal(2);
    });
  });
}
mocha.run();

The tests I'm running look like this:

{ todo: 
  [ { name: 'POST /todos',
      should: 'create a new todo',
      method: 'POST',
      endpoint: '/todos',
      body: [Object] } ] }

(though at this point my test is just trying to check a basic expect)

Based on the console.logs the iteration seems fine and it appears to be adding the tests, so I'm confident in the flow of operations, I just can't get any execution or errors.