First Move (11~18) - Code, Learn, Build
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First Move (11~18) - Code, Learn, Build

Structured, level-based technology learning paths from foundational exploration to industry mastery.

Learning Domains

  • Python Programming (Active)
  • Computer Science Core
  • Web Development
  • AI & Machine Learning

Platform Architecture

  • Level-Based Progression
  • Decoupled Content Schema
  • Modular Code Execution Engine
  • Curated Official Resources

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← Software Testing & Quality Assurance|Level 2: Test Doubles (Mocks/Spies) & Integration Testing

3. Test Doubles: Mocks, Stubs, Spies & Dependency Injection

Lesson 3 of 6
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Test Doubles: Mocks, Stubs, Spies & Dependency Injection

Isolate network HTTP calls and database IO using Dummy, Stub, Mock, and Spy test doubles in Vitest/Jest.

Test Double Taxonomy

### Types of Test Doubles (Gerard Meszaros Taxonomy) - **Dummy**: Unused placeholder objects passed strictly to satisfy parameter signatures. - **Stub**: Provides hardcoded canned responses to method calls during the test. - **Spy**: Wraps real functions, recording execution counts and received argument details. - **Mock**: Pre-programmed object specifying expected call sequences and verifying assertions automatically.
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