Angular unit testing tutorial with examples

Angular testing encompasses various methodologies, including unit, integration, and end-to-end tests, each serving unique purposes in ensuring application reliability. Unit tests focus on isolated components like services or pipes and are quick and efficient, forming the majority of testing strategies. Integration tests evaluate module interactions, while end-to-end tests simulate real user interactions to guarantee complete system functionality, albeit with increased complexity and execution time. The Angular framework facilitates component testing through utilities like TestBed and async, enabling developers to test component creation, properties, and interactions. The use of test runners such as Karma, Mocha, and Jasmine, along with tools like ngentest for auto-generating test specs, streamlines the testing process. Mocking dependencies allows testing in isolation by creating simplified replicas of external services. Testing pipes and directives ensures data transformation and UI behavior are accurately managed. Incorporating unit testing into the CI/CD pipeline enhances application stability by automating the evaluation of code functionality and error detection throughout the development lifecycle.