🧪 Spring Boot Integration Testing – CRUD Example

This project demonstrates Integration Testing in Spring Boot using a simple Product CRUD API with H2 in-memory database.
The tests verify the REST API endpoints end-to-end (Controller → Service → Repository → Database).

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🚀 Tech Stack

• Java 21
• Spring Boot 3.5.6
• Spring Data JPA
• H2 Database (in-memory)
• JUnit 5
• RestTemplate for HTTP requests
• @Sql for test data setup/cleanup

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📂 Features Tested

The integration tests cover full CRUD functionality:

1. Create (POST)

   • testAddProduct() → Adds a product via POST /products and validates DB state.

2. Read All (GET)

   • testGetProducts() → Fetches all products with GET /products.

3. Read by ID (GET)

   • testFindProductById() → Fetches product details by ID using GET /products/{id}.

4. Update (PUT)

   • testUpdateProduct() → Updates an existing product with PUT /products/update/{id}.

5. Delete (DELETE)

   • testDeleteProduct() → Deletes a product with DELETE /products/delete/{id}.

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🔑 Key Concepts Demonstrated

• @SpringBootTest(webEnvironment = RANDOM_PORT)
  Loads the full Spring application context and starts the server on a random port.

• @LocalServerPort
  Injects the server port for real HTTP requests during tests.

• RestTemplate in tests
  Sends real HTTP requests to the running Spring Boot app.

• @Sql annotation
  Preloads and cleans test data before/after each test method.

• H2 In-Memory Database
  Provides a lightweight, isolated database for testing.

• Assertions in JUnit 5

  • assertEquals, assertNotNull, assertAll for grouped assertions.

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⚡ Why This Matters

• Ensures the entire flow works correctly (Controller → Service → Repository → DB).
• Validates real database operations instead of mocked calls.
• Guarantees endpoints behave as expected in production-like scenarios.

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