Function setup

test/engine-operator.test.js:33–45

(conditions = baseConditions)

  }
  let eventSpy
  function setup (conditions = baseConditions) {
    eventSpy = sandbox.spy()
    const engine = engineFactory()
    const rule = factories.rule({ conditions, event })
    engine.addRule(rule)
    engine.addOperator('startsWithLetter', (factValue, jsonValue) => {
      if (!factValue.length) return false
      return factValue[0].toLowerCase() === jsonValue.toLowerCase()
    })
    engine.addFact('dictionary', dictionary)
    engine.on('success', eventSpy)
    return engine
  }

  describe('evaluation', () => {
    it('emits when the condition is met', async () => {