[JEST] Jest Functions with AWS

JEST TESTING

• mockdata
  • Use Mockdata files to store fake data values for the testing
• jest.mock
  • take away the functionality of it
  • do nothing (we don't have to run everything)
  • I don't want to send a notification of sns so did a mock
• Set a global variable of response
• jest.requireActual
  • it uses all thd data
  • uses actual function
  • using only one function there to require it
  • most of the times we do only mock whole file but it uses some
• jest.fn
  • jest mock function (How many times it was called)
  • wrapping our function and add extra unique functions there
  • After wrapping this function, we can use them. 
• beforeEach
  • jest.clearAllMocks() 
    • This helps with fresh start
• jest.toHaveBeenCalled()
• toMatchSnapShot()
  • If you know what output to be >> check it
  • When it's dynamic we use toEqual.
• it
  • testing function
  • 1st: Title
  • 2nd: Function
• describe
  • Grouping stuff
  • Suggestions: Reading Describe Blocks in JEST library
• expect
  • rejects.toThrow(Error)
    • Error >> Jest knows
• mockImplementation
  • Implement the function if it's used after the function
  • ex: daos.content.getContent[content name].mockImplementation([OWN FUNCTION])
• arrow function(extra)
  • () => ({})
    • returns data
• not.toHaveBeenCalled()
  
  • wants not to be called.
• Data Type
  • Date data
    • ISO Date
      • toIsoDate([date])
  • You can find parameter types in AWS Step Functions >> State Machine
• guid()
  • Format of the ID (ID is following this pattern)
• property
  • constants
• Array
  • toContain ([Value])