Testing React components can be complicated when imported modules interfere with functionality, prompting the use of dependency injection (DI) as a solution. DI involves passing dependencies to a module rather than having the module create them, enabling easier testing through loose coupling. Although not commonly used in React, DI can be implemented by injecting dependencies as props, allowing components like HeroesListPage to use fake instances of modules during testing without altering the application code. This approach simplifies component testing by avoiding direct usage of modules during tests, although developers should consider whether mocking at the network request level might be more appropriate. While frameworks like Angular have built-in DI systems, React developers can use libraries such as InversifyJS for a more advanced solution. Cypress Component Testing doesn't support full module mocking, but it can utilize DI to facilitate testing, ensuring the application remains unchanged while offering flexibility in testing environments.