The hottest Unit Testing Substack posts right now

A good unit test should be idempotent and independent/atomic.
Unit tests should be fast by mocking dependencies to not delay the development process.
Unit test code is as important as product code and should follow guidelines for elegant code.

Data Engineers often struggle with implementing unit tests due to factors like focus on moving fast and historical lack of emphasis on testing.
Unit testable code in data engineering involves keeping functions small, minimizing side effects, and ensuring reusability.
Implementing unit tests can elevate a data team's performance and lead to better software quality and bug control.

It is recommended not to test private methods, as they are for internal use only.
You may need to test a private method when working with legacy code, fixing bugs, or dealing with widget dependencies.
To test a private method inside a widget, create a forwarder method, use the @visibleForTesting annotation, and follow specific steps based on widget type.

Express precise instructions for Large Language Models to be productive.
Design codebases with reduced complexity and ambiguity for better LLM performance.
Employ widely-used coding conventions and avoid hidden logic to facilitate LLM understanding.

Unit testing @Observable view models is crucial for ensuring reliability and stability in iOS development.
The Observation Framework provides a solution for testing @Observable properties using withObservationTracking, improving the unit testing process.
By leveraging the ObservationTestUtils package, developers can streamline unit testing of @Observable view models with less boilerplate code.

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Unstructured concurrency introduces a different approach to handling asynchronous code compared to structured concurrency like async/await.
When dealing with unstructured concurrency like Tasks, testing can become challenging and may require using XCTestExpectation to handle closure-based asynchronous operations.
To overcome testing challenges with unstructured concurrency, leverage mocks, the defer keyword, and XCTestExpectation to ensure precise test execution.

Unit Testing with async/await allows for writing robust and maintainable software using modern language features.
Async tests focus on checking interactions with dependencies, successful function calls, and handling error states.
By making code testable through dependency injection, it becomes cleaner and easier to reason about, with encapsulated logic and separated responsibilities.

ChatGPT v4 is revolutionizing software development by generating legitimate code and assisting with complex coding problems.
ChatGPT can accelerate learning and help programmers gain valuable insights into new concepts.
The integration of ChatGPT in IT processes can lead to accelerated software development, reduction in code, and faster onboarding in complex environments.

Combine and async/await can be used together to write robust and maintainable software with modern language features.
Testing @ObservableObject view models, Combine publishers in async methods, and Combine publishers converted to AsyncSequence are key in achieving unit test mastery.
Understanding the interoperation between Combine and async/await is a powerful skill for writing unit tests and marrying the two concurrency approaches.

Having unit tests for SQL queries can help catch bugs introduced during code refactorings or changes.
When writing unit tests for SQL queries, focus on testing the specific parts responsible for building the query rather than the entire method.
Refactoring code for testability can involve moving pure functions outside of the class for easier testing and simplifying methods to focus on specific tasks.