Cucumber是平实语言版的unit test，可用于包层次的测试。优势在于它允许非程序员参与，需求更加明确。
测试方法：
https://www.cnblogs.com/TankXiao/archive/2012/02/20/2347016.html
BDD/Functional test framwork: Cucumber
TDD:
https://cucumber.io/
Gherkin
plain text语音来描述unit test中的arrange(mock), act, assert。
例子
Scenario: Breaker guesses a word
Given the Maker has chosen a word
When the Breaker makes a guess
Then the Maker is asked to score
