How do you properly and effectively test Riverpod providers in isolation, including overriding a specific provider's own dependency with a controlled mock implementation specifically for a given unit test?

Testing Riverpod providers effectively typically involves creating a genuinely dedicated ProviderContainer specifically for use within your particular test, letting you directly read and properly evaluate a given provider's own actual resulting value completely outside of any real widget tree at all, and Riverpod's own built in override mechanism lets you cleanly substitute a specific provider's own real implementation with a controlled, predictable mock version specifically for testing purposes, which is especially useful for properly and reliably testing a provider that genuinely depends on an external service, such as a real network client, without ever needing to make an actual real live network call during your test.

final container = ProviderContainer(
  overrides: [apiClientProvider.overrideWithValue(mockApiClient)],
);
final result = await container.read(currentUserProvider.future);