• Unit tests: Unit tests are atomic. They are within the scope of one component or action or reducer or saga and do not go beyond the scope of this atomic component.

  • Example: Unit tests do not involve reducer && saga being tested together or component && action && reducer && saga being tested together.

• Integration tests: Integration tests are an extension of unit tests and involve integrating multiple components.

  • Example: component click on button -> throws an action -> watched by the saga -> calls an api endpoint (mocked) -> modify reducers state -> changes something on the same or another component.
• End to end tests: We use Cypress for end to end testing where we test the end results like how an external user with interact with our system / UI.

Resources

• 🤔 Question for tech folks 🤔
  
  "How do you differentiate between integration tests and end-to-end tests? They're very similar and I cannot for the life of me define a concrete line where one ends and the other begins."
  
  Anyone have thoughts or resources on this?

  — Carolyn Stransky (@carolstran) November 13, 2019

• https://kentcdodds.com/blog/unit-vs-integration-vs-e2e-tests