The Complete React Developer Course (with Hooks and Redux) - Build It: Adding Total Selector

The video tutorial introduces a new feature for Expensify, focusing on creating an expense list header. The tutorial guides viewers through creating a selector function to sum expenses and writing test cases using Test Driven Development (TDD). It emphasizes the use of JavaScript methods like map and reduce, and demonstrates how to refactor code confidently with a robust test suite.

What new insight or understanding did you gain from this video?