Testing

TypeScript

Advanced TypeScript Mocking: jest.fn() with Generics, ts-mockito, and Partial Mocks

TypeScript mocking has one goal: replace real dependencies with test doubles that are fully type-checked. The toolbox includes jest.fn() with generic parameters, jest.Mocked for class/interface mocks, jest.spyOn for partial mocks, and ts-mockito for fluent mock setup. This guide covers each pattern with realistic examples and explains

Vue.js

Cypress Component Testing for Vue: Mount API, Real Browser Tests, Visual Assertions

Cypress component testing runs Vue components in a real browser — not jsdom, not a virtual DOM. This means your CSS is applied, browser APIs work correctly, and user interactions behave exactly as they do in production. Unlike Vitest + Vue Test Utils which runs in Node, Cypress component tests give you

Flutter

Testing Flutter BLoC and Cubit with bloc_test

The bloc_test package provides blocTest() — a declarative test helper that makes BLoC and Cubit testing concise. You define the initial state, the events/actions to trigger, and the expected state sequence. Compared to manually subscribing to BLoC streams, blocTest() handles stream subscription, async operations, and teardown automatically. Key Takeaways

Vue.js

Testing Vue Router: Route Guards, Navigation, and router-view in Component Tests

Testing Vue Router involves three distinct scenarios: testing route guards in isolation (pure functions), testing components that use router composables (useRoute, useRouter), and testing the full router flow with real navigation. Each requires a different approach. This guide covers all three with Vitest and Vue Test Utils 2. Key Takeaways

Angular

Spectator for Angular: Reducing TestBed Boilerplate with createComponent and createService

Spectator is an Angular testing library that wraps TestBed with a simpler, less verbose API. Instead of 20 lines of configureTestingModule, compileComponents, createComponent, and detectChanges, you get a one-liner factory that handles all of it. This guide covers the full Spectator API: createComponent, createService, SpyObject mocks, and event testing. Key

TypeScript

Testing tRPC Routers: createCaller Pattern and End-to-End Type-Safe Tests

tRPC procedures are TypeScript functions — they accept typed input, receive a context, and return typed output. The createCaller pattern lets you call tRPC procedures directly in tests without an HTTP server. This gives you full type safety, fast execution, and the ability to inject test contexts (mocked databases, authenticated users)

Flutter

Mocking in Flutter with mocktail: Comparison with mockito

Mocking in Flutter means replacing real dependencies (API clients, database repositories, platform services) with test doubles that you control. Mocktail is the modern choice: it doesn't require code generation, works with null safety out of the box, and has a clean API. Mockito is the alternative — it requires

Vue.js

Testing Pinia Stores: Unit Testing, Mocking Stores in Component Tests

Pinia stores are plain JavaScript/TypeScript objects — state, getters, and actions — which makes them easy to test directly without mounting Vue components. For unit tests, call setActivePinia(createPinia()) in beforeEach and import your stores normally. For component tests, use createTestingPinia() from @pinia/testing to mount components with full control over

Angular

Testing Angular Services: HttpClientTestingModule, Mocking Dependencies, RxJS Marble Testing

Angular services are the workhorses of Angular applications — they handle HTTP calls, state management, caching, and business logic. Testing services involves two main concerns: intercepting HTTP requests with HttpClientTestingModule, and isolating service dependencies with spy objects. For complex observable chains, RxJS marble testing gives you frame-level control over timing. This

TypeScript

Testing Zod Schemas: Unit Tests for Validators, Error Messages, and Transforms

Zod schemas are code — they contain business logic (required fields, format constraints, cross-field validation) that can break if changed carelessly. Testing Zod schemas means verifying that valid data passes, invalid data fails with the right error messages, and transforms produce the expected output types. This guide covers testing patterns for

Vue.js

Vitest for Vue: Setup, Coverage, Mocking Vue Router and Composables

Vitest is the fastest testing framework for Vue 3 projects. Because it shares the same Vite build pipeline as your application, it understands Vue SFCs natively, resolves aliases automatically, and runs significantly faster than Jest. This guide covers configuring Vitest for Vue, mocking Vue Router and Pinia, and setting up

Flutter

Flutter Integration Testing: integration_test Package and Patrol

Flutter integration tests run your actual app on a real device or emulator — including platform channels, camera, location, and real network requests. The integration_test package (part of the Flutter SDK) replaces the deprecated flutter_driver. For advanced scenarios like system dialogs, notifications, and deep links, Patrol provides a higher-level