Tutorials covering the frameworks and libraries that shape how modern applications are built — Angular, React, Vue, and the ecosystem tools that surround them. Each chapter is standalone, built around real examples and verified facts.
The mount phase, the render pipeline, and the scheduler queue are three stages of the same mechanism. The mount phase creates the component instance, runs the setup, and executes the render function for the first time. The render pipeline turns the template into a virtual DOM tree and patches it into real DOM nodes. The…
The previous chapter covered the testing infrastructure: Jasmine for the test syntax, Karma for the test runner, TestBed for the testing module, and ComponentFixture for the component wrapper. This chapter goes deeper into the two most common kinds of tests in an Angular application: component tests and service tests. They are different because components have…
React Fiber is not a feature that application developers interact with directly. It is the internal engine that determines how and when React renders. Before Fiber, React used a recursive reconciler that walked the component tree synchronously. Once rendering began, it could not be interrupted. A deeply nested component tree or an expensive render could…
A quick-reference for Vue 3 APIs, reactivity, components, and internals. Organized for lookup, not for reading. Component Definition Syntax Meaning <script setup> Composition API, compiled to setup() defineComponent({}) Options API with TS support export default {} Options API object <script setup lang=”ts”> TypeScript + Composition API <script setup vapor> Vapor Mode component (Vue 3.6+) Reactivity:…
The previous chapters covered the testing infrastructure: Jasmine, Karma, TestBed, and ComponentFixture. They showed how to write component tests and service tests. This chapter goes deeper into the TestBed itself — the tool that configures the dependency injection context for every test. Understanding TestBed is understanding how Angular’s dependency injection works in the testing environment….
React’s rendering pipeline is divided into two distinct phases with different rules, different guarantees, and different failure modes. The render phase is where React calls component functions, compares the new element tree to the previous one, and determines what needs to change. The commit phase is where React applies those changes to the DOM, runs…
The previous chapters covered the testing infrastructure and the component and service testing patterns. This chapter covers the two hardest parts of testing an Angular application: asynchronous behavior and signals. An async test that does not wait for the operation to complete will assert on stale data. A signal test that does not trigger change…
Strict Mode is a development-only wrapper that deliberately runs certain parts of React’s lifecycle more than once. It is not a bug, a performance problem, or something that happens in production. It is a diagnostic tool that surfaces code which violates React’s rules—impure renders, missing effect cleanups, and state that does not reset correctly. The…
Playwright is a modern end-to-end testing framework built by Microsoft. It runs tests in real browsers — Chromium, Firefox, and WebKit — and it is designed around a set of principles that make tests reliable: auto-waiting, web-first assertions, and test isolation. Angular has embraced Playwright as a first-class E2E testing solution through a set of…
Concurrent rendering is not a feature that makes React faster. It is a scheduling model that changes when React does its work. The scheduler assigns a priority to every state update, processes the highest-priority work first, and yields to the browser between small slices of work so that user input is never blocked by a…