Testing custom React hooks ensures your reusable hook logic works correctly and handles edge cases properly. With over 12 years of React development experience since 2014 and as the creator of CoreUI, I’ve written and tested hundreds of custom hooks. React Testing Library provides renderHook utility specifically designed for testing hooks in isolation without needing a component. This approach allows you to test hook logic, state updates, and side effects independently.

Mocking dependencies in Node.js tests isolates the code under test from external services, databases, and APIs for fast, reliable unit tests. As the creator of CoreUI with over 12 years of Node.js experience since 2014, I’ve written comprehensive test suites with extensive mocking. Jest provides powerful mocking capabilities including module mocks, function mocks, and spies that work seamlessly with Node.js. This approach creates independent tests that run quickly without external dependencies.

Testing React components ensures your UI behaves correctly and prevents regressions when refactoring or adding new features. As the creator of CoreUI with over 12 years of React experience since 2014, I’ve built comprehensive test suites for production applications. Jest is a JavaScript testing framework that provides fast test execution, snapshot testing, and built-in mocking capabilities. This approach creates maintainable test suites that verify component behavior and output.

Testing Node.js applications with Mocha provides a flexible and feature-rich testing framework with excellent async support. As the creator of CoreUI with over 12 years of Node.js experience since 2014, I’ve used Mocha extensively for backend API testing. Mocha offers a simple, extensible testing interface with support for multiple assertion libraries and reporters. This approach creates comprehensive test suites with clear test organization and detailed error reporting.

Testing Node.js applications ensures code reliability and prevents regressions as your codebase grows and evolves. With over 12 years of Node.js development experience since 2014 and as the creator of CoreUI, I’ve written comprehensive test suites for production backends. Jest is a modern testing framework that provides fast test execution, built-in mocking, and excellent error messages out of the box. This approach creates maintainable test suites with minimal configuration.

Jest is a modern testing framework that offers faster test execution, better error messages, and snapshot testing compared to Karma/Jasmine. As the creator of CoreUI with over 12 years of Angular experience since 2014, I’ve migrated several large projects from Karma to Jest for improved developer experience. Jest runs tests in Node.js using jsdom instead of real browsers, making it significantly faster for unit tests. The migration requires installing Jest packages and configuring Angular to use Jest instead of Karma.

Jasmine is Angular’s default testing framework, providing a behavior-driven development syntax for writing clean, readable tests. As the creator of CoreUI with over 12 years of Angular experience since 2014, I’ve used Jasmine extensively for testing thousands of components and services. Jasmine offers describe blocks for test suites, it blocks for individual tests, and powerful matchers for assertions. The framework includes spies for mocking functions and tracking calls without external dependencies.

Angular directives modify DOM behavior and appearance, making testing essential to ensure they work correctly across different scenarios and edge cases. With over 12 years of Angular development experience since 2014 and as the creator of CoreUI, I’ve tested numerous custom directives in production applications. Testing directives requires creating a test component that uses the directive, then asserting that the directive correctly modifies the DOM or behavior. This approach verifies both attribute directives that change element behavior and structural directives that modify the DOM structure.

Angular pipes transform display values in templates, and testing them ensures your data formatting logic works correctly with edge cases and unexpected inputs. As the creator of CoreUI with over 12 years of Angular experience since 2014, I’ve built and tested numerous custom pipes for enterprise applications. Testing pipes is straightforward because they’re pure functions that take input and return transformed output without side effects. The approach involves instantiating the pipe directly and calling its transform method with various test inputs.

Angular services contain critical business logic and data operations that must be thoroughly tested to prevent bugs in production applications. With over 12 years of Angular development experience since 2014 and as the creator of CoreUI, I’ve written comprehensive test suites for countless enterprise services. Testing services is simpler than testing components because services have no template or DOM to manage, focusing purely on logic and method outputs. The approach uses TestBed to inject the service and Jasmine to assert that methods behave correctly with various inputs.