The most Rspec-like mocha test I've managed to write so far

rspec-like-test.js

// The single letter variables are designed to be invisible
// Yes, there are a few global variables: t, s and expect
// The system under test has no globals, so I can't conflict!

var h = require('../spec-helper.js');

var command = require('../../lib/command-round-init.js');

describe('Command: round-init', function() {
  beforeEach(function() {
    t.calcLog = h.stubCalculationLog();
    t.round = 22;
  })
  function runCommand(done) {
    t.callback = s.spy(function() { done() })
    command({db: t.db, log: t.log}, t.timer, t.round, t.callback);
  }

  function shouldBehaveLikeCommand() {
    it('should start calculation log with info', function() {
      expect(t.calcLog.wrap).to.be.calledOnce
      expect(t.calcLog.wrap).to.be.calledWith(
        t.db, t.log, 'round-init', 22)
      expect(t.calcLog.wrap).to.be.calledBefore(t.db.query)
    })
    it('should run SQL with round id', function() {
      expect(t.db.query).to.be.calledOnce
      expect(t.db.query).to.be.calledWithMatch("INSERT IGNORE", [22])
    })
    it('should log SQL and params', function() {
      expect(t.log.info).to.be.calledWithMatch(
        "SQL:", [t.db.query.firstCall.args[0], 22])
    })
    it('should end calculation log after query', function() {
      expect(t.calcLog.callback).to.be.calledOnce
      expect(t.calcLog.callback).to.be.calledAfter(t.db.query)
    })
  }

  context('successful query', function() {
    beforeEach(function() { t.db.query.yieldsAsync() })
    beforeEach(runCommand)

    shouldBehaveLikeCommand()

    it('should callback once complete', function() {
      expect(t.callback).to.be.calledOnce
    })
  })

  context('failed query', function() {
    beforeEach(function() { t.db.query.yieldsAsync(new Error('failed')) })
    beforeEach(runCommand)

    shouldBehaveLikeCommand()

    it('should callback with error', function() {
      expect(t.callback).to.be.calledOnce
      expect(t.callback).to.be.calledWith(s.match(Error))
    })
  })

})

spec-helper.js

// tel, chai, sinon and sinon-chai all stock installs from npm

var Tel = require('tel');

var chai = require('chai');
global.expect = chai.expect;

var sinon = require('sinon');
chai.use(require('sinon-chai'));

beforeEach(function() {
    global.s = sinon.sandbox.create();
    s.match = sinon.match;
    global.t = Tel();
    t.db = {
        query: s.stub()
    };
    t.log = {
        debug: s.stub(),
        info: s.stub(),
        notice: s.stub(),
        warn: s.stub(),
        error: s.stub()
    };
    t.callback = s.spy();
});
afterEach(function() {
    s.restore();
})

// You'll have to take my word for it that this does something vaguely sensible.
var calcLog = require('../lib/calculation-log');
exports.stubCalculationLog = function stubCalculationLog() {
    var stubbedCalcLog = {};

    s.stub(calcLog, 'wrap', fakeCalcWrap);
    function fakeCalcWrap(/*..., callback, body*/) {
        var args = arguments.length;
        stubbedCalcLog.callback = s.spy(arguments[args - 2]);
        arguments[args - 1](stubbedCalcLog.callback);
    }
    stubbedCalcLog.wrap = calcLog.wrap;

    return stubbedCalcLog;
}