The Complete React Developer Course (with Hooks and Redux) - Testing Filters Reducer

The video tutorial covers the process of testing Redux reducers in JavaScript. It begins with an introduction to reducers and the setup of test files. The tutorial then demonstrates how to test default values in the Redux store, followed by testing the 'sort by' functionality for both amount and date. Finally, it covers testing for text, start date, and end date filters, ensuring that the Redux store behaves as expected. The tutorial emphasizes the importance of testing to allow for refactoring without breaking functionality.

What is the primary role of reducers in Redux?

• To fetch data from APIs

• To handle asynchronous operations

• To manage the UI components

• To update the state based on actions

Where should the test file for the filters reducer be created?

• In the tests reducers folder

• In the source components folder

• In the main application folder

• In the Redux store folder

What is the purpose of the first test case for the filters reducer?

• To check if the reducer can handle errors

• To ensure default values are set correctly

• To test the reducer's interaction with the UI

• To verify the reducer's performance

Which action type is used to test the default values in Redux?

• START

• RESET

• INIT

• SET_DEFAULTS

What should the 'sort by' value change to when the 'sort by amount' action is dispatched?

• Amount

• Default

• Text

• Date

Why is it important to pass a state to the reducer when testing 'sort by date'?

• To check if the reducer can handle multiple actions

• To test the reducer's performance

• To verify the reducer's ability to change from a non-default state

• To ensure the reducer can handle undefined states

What is the expected outcome when the 'set text filter' action is dispatched?

• The text filter should be updated with the provided value

• The text filter should be removed

• The text filter should be set to an empty string

• The text filter should remain unchanged

How should the start date be set in the test case for 'set start date filter'?

• As a string representing the date

• As an undefined value

• As a number representing the timestamp

• As a moment instance

What is the significance of using '2B' in the test assertions?

• It is used for comparing functions

• It is used for comparing primitive values

• It is used for comparing arrays

• It is used for comparing objects

What is the next focus area after completing the reducer tests?

• Adding more actions to the reducer

• Testing React components

• Improving the reducer's performance

• Refactoring the Redux store