Software Engineering 2

Test-driven development (TDD) is a software development practice that involves writing automated tests for software features before writing the actual code to implement those features. The process starts by writing a failing test case for the desired functionality, then writing the minimum amount of code required to make the test pass, and finally refactoring the code to improve its design and maintainability. This iterative process helps ensure that the software is thoroughly tested and that it meets the requirements specified by the customer or user.

A mock object (also called a test double) is a simulated object that mimics the behavior of a real object in a controlled way. It is used in unit testing to isolate the code being tested from other parts of the system, such as dependencies on external libraries or services. By using a mock object instead of the real object, developers can test their code in isolation and ensure that it behaves correctly under a variety of conditions. For example, a mock object could be used to simulate a database connection or a network service, allowing the developer to test their code without actually interacting with those external systems. Overall, mock objects are an important tool for unit testing because they allow developers to test their code thoroughly and identify potential issues early in the development process.