The names of tests don't need to be prefixed with "test": it's redundant. It's also a good habit to prefix functions on modules with `.` in the test name. In addition, this test and the next could be grouped together for clarity in the test output:

```js
'.indexOf': {
    'no index': function () {
        /* contents of 'testIndexOf' here */
    },
    'index': function () {
        /* contents of 'testIndexOfFromIndex' here */
    }
}