Learn when to use mock testing to create effective and challenging test scenarios

Mock objects are lookalikes that replace external systems to help maintain testability. For example, instead of pulling live weather data, a mocked service can return predefined temperatures, allowing testers to verify the display without relying on the real service. Mocks can be difficult to build and maintain, especially when the external service evolves. However, they are useful when components are slow, unavailable, indeterministic, under development, or require rare responses.  Test setups vary based on the number of mocks used:  Component tests mock everything except the tested module. Integration tests replace some or most components with mocks. End-to-end tests use real components whenever possible. Mocks can be implemented via MockServer, Mockoon, Mocki, or frameworks like JMock and Mockito. Dependency Injection helps swap components efficiently. Some systems allow modifying components to serve as their own mock or using control interfaces and test-specific triggers (e.g., a test user named "CrashAtStepX").

Improve user satisfaction and software resilience by prioritising thoughtful error messaging and a good error culture

Where to click and where to look? These are the questions that need to be defined in an automated UI test script. Why not use images to show it, rather than text to describe it?