Mocha this

#### Resolves #1239

Moving from #1369

Continuing changes from #1344 in a series of quality updates to our test suite, this moves everything into `beforeEach` blocks and uses `this` instead of variables.

**Changes:**
- Fix whitespace
- Move all logic to `beforeEach` blocks
- Switch to using `this` instead of `var`s (thisify all the things)