Testing Guide

Overview

Testing is crucial for maintaining code quality and preventing regressions. This guide covers testing strategies for both the Java Spring Boot backend and React TypeScript frontend.

Backend Testing (Spring Boot)

Testing Framework

The backend uses:

JUnit 5 - Testing framework
Spring Boot Test - Spring testing utilities
Mockito - Mocking framework
AssertJ - Fluent assertions

Project Structure

Iqüea_back/
├── src/
│   ├── main/java/com/edu/mcs/Iquea/
│   │   ├── controllers/
│   │   ├── services/
│   │   ├── repositories/
│   │   └── models/
│   └── test/java/com/edu/mcs/Iquea/
│       ├── IqueaApplicationTests.java
│       ├── controllers/
│       ├── services/
│       └── repositories/

Running Tests

Run All Tests

Execute all tests using Maven Wrapper:

cd Iqüea_back
./mvnw test

On Windows:

.\mvnw.cmd test

Run Specific Test Class

Run a single test class:

./mvnw test -Dtest=ProductoServiceTests

Run with Coverage

Generate test coverage report:

./mvnw clean test jacoco:report

View report at target/site/jacoco/index.html

Application Context Test

Basic smoke test to verify Spring context loads:

package com.edu.mcs.Iquea;

import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class IqueaApplicationTests {

    @Test
    void contextLoads() {
        // Verifies that the Spring application context loads successfully
    }
}

Unit Testing Services

Test service layer with mocked dependencies:

package com.edu.mcs.Iquea.services;

import com.edu.mcs.Iquea.mappers.ProductoMapper;
import com.edu.mcs.Iquea.models.Producto;
import com.edu.mcs.Iquea.models.dto.detalle.ProductoDetalleDTO;
import com.edu.mcs.Iquea.repositories.ProductoRepository;
import com.edu.mcs.Iquea.services.implementaciones.ProductoServiceImpl;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;

import java.util.Optional;

import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.assertThatThrownBy;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyString;
import static org.mockito.Mockito.*;

@ExtendWith(MockitoExtension.class)
class ProductoServiceTests {

    @Mock
    private ProductoRepository productoRepository;

    @Mock
    private ProductoMapper productoMapper;

    @InjectMocks
    private ProductoServiceImpl productoService;

    private Producto producto;
    private ProductoDetalleDTO productoDTO;

    @BeforeEach
    void setUp() {
        producto = new Producto();
        producto.setSku("CHAIR-001");
        producto.setNombre("Silla Moderna");

        productoDTO = new ProductoDetalleDTO();
        productoDTO.setSku("CHAIR-001");
        productoDTO.setNombre("Silla Moderna");
    }

    @Test
    void crearProducto_ConSkuUnico_DeberiaCrearProducto() {
        // Arrange
        when(productoRepository.existsBySku(anyString())).thenReturn(false);
        when(productoMapper.toEntity(any(ProductoDetalleDTO.class))).thenReturn(producto);
        when(productoRepository.save(any(Producto.class))).thenReturn(producto);

        // Act
        Producto resultado = productoService.crearProducto(productoDTO);

        // Assert
        assertThat(resultado).isNotNull();
        assertThat(resultado.getSku()).isEqualTo("CHAIR-001");
        verify(productoRepository).save(producto);
    }

    @Test
    void crearProducto_ConSkuDuplicado_DeberiaLanzarExcepcion() {
        // Arrange
        when(productoRepository.existsBySku(anyString())).thenReturn(true);

        // Act & Assert
        assertThatThrownBy(() -> productoService.crearProducto(productoDTO))
                .isInstanceOf(IllegalArgumentException.class)
                .hasMessageContaining("Ya existe un producto con el SKU");

        verify(productoRepository, never()).save(any());
    }

    @Test
    void obtenerProductoPorId_ConIdExistente_DeberiaRetornarProducto() {
        // Arrange
        Long id = 1L;
        when(productoRepository.findById(id)).thenReturn(Optional.of(producto));

        // Act
        Optional<Producto> resultado = productoService.obtenerProductoPorId(id);

        // Assert
        assertThat(resultado).isPresent();
        assertThat(resultado.get().getSku()).isEqualTo("CHAIR-001");
    }

    @Test
    void obtenerProductoPorId_ConIdNoExistente_DeberiaRetornarVacio() {
        // Arrange
        Long id = 999L;
        when(productoRepository.findById(id)).thenReturn(Optional.empty());

        // Act
        Optional<Producto> resultado = productoService.obtenerProductoPorId(id);

        // Assert
        assertThat(resultado).isEmpty();
    }

    @Test
    void actualizarProducto_ConSkuExistente_DeberiaActualizarProducto() {
        // Arrange
        String sku = "CHAIR-001";
        when(productoRepository.findBySku(sku)).thenReturn(Optional.of(producto));
        when(productoRepository.save(any(Producto.class))).thenReturn(producto);

        // Act
        Producto resultado = productoService.actualizarProducto(sku, productoDTO);

        // Assert
        assertThat(resultado).isNotNull();
        verify(productoMapper).updatefromEntity(productoDTO, producto);
        verify(productoRepository).save(producto);
    }

    @Test
    void borrarProducto_ConIdExistente_DeberiaEliminarProducto() {
        // Arrange
        Long id = 1L;
        when(productoRepository.existsById(id)).thenReturn(true);

        // Act
        productoService.borrarProducto(id);

        // Assert
        verify(productoRepository).deleteById(id);
    }

    @Test
    void borrarProducto_ConIdNoExistente_DeberiaLanzarExcepcion() {
        // Arrange
        Long id = 999L;
        when(productoRepository.existsById(id)).thenReturn(false);

        // Act & Assert
        assertThatThrownBy(() -> productoService.borrarProducto(id))
                .isInstanceOf(RuntimeException.class)
                .hasMessageContaining("no existe");

        verify(productoRepository, never()).deleteById(any());
    }
}

Testing Best Practices:

Use descriptive test names: methodName_condition_expectedResult
Follow Arrange-Act-Assert pattern
Test both success and failure scenarios
Use @BeforeEach for common setup
Verify mock interactions with verify()

Integration Testing Controllers

Test controllers with MockMvc:

package com.edu.mcs.Iquea.controllers;

import com.edu.mcs.Iquea.models.Producto;
import com.edu.mcs.Iquea.models.dto.detalle.ProductoDetalleDTO;
import com.edu.mcs.Iquea.services.implementaciones.ProductoServiceImpl;
import com.edu.mcs.Iquea.mappers.ProductoMapper;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.http.MediaType;
import org.springframework.test.web.servlet.MockMvc;

import java.util.Arrays;
import java.util.List;
import java.util.Optional;

import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyLong;
import static org.mockito.Mockito.when;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;

@WebMvcTest(ProductoController.class)
class ProductoControllerTests {

    @Autowired
    private MockMvc mockMvc;

    @Autowired
    private ObjectMapper objectMapper;

    @MockBean
    private ProductoServiceImpl productoService;

    @MockBean
    private ProductoMapper productoMapper;

    @Test
    void listarTodos_DeberiaRetornarListaDeProductos() throws Exception {
        // Arrange
        Producto producto1 = new Producto();
        producto1.setNombre("Silla");
        Producto producto2 = new Producto();
        producto2.setNombre("Mesa");

        List<Producto> productos = Arrays.asList(producto1, producto2);
        List<ProductoDetalleDTO> productosDTO = Arrays.asList(new ProductoDetalleDTO(), new ProductoDetalleDTO());

        when(productoService.obtenertodoslosproductos()).thenReturn(productos);
        when(productoMapper.toDTOlist(productos)).thenReturn(productosDTO);

        // Act & Assert
        mockMvc.perform(get("/api/productos"))
                .andExpect(status().isOk())
                .andExpect(content().contentType(MediaType.APPLICATION_JSON))
                .andExpect(jsonPath("$.length()").value(2));
    }

    @Test
    void obtenerPorId_ConIdExistente_DeberiaRetornarProducto() throws Exception {
        // Arrange
        Long id = 1L;
        Producto producto = new Producto();
        producto.setNombre("Silla");
        ProductoDetalleDTO productoDTO = new ProductoDetalleDTO();

        when(productoService.obtenerProductoPorId(id)).thenReturn(Optional.of(producto));
        when(productoMapper.toDTO(producto)).thenReturn(productoDTO);

        // Act & Assert
        mockMvc.perform(get("/api/productos/{id}", id))
                .andExpect(status().isOk())
                .andExpect(content().contentType(MediaType.APPLICATION_JSON));
    }

    @Test
    void obtenerPorId_ConIdNoExistente_DeberiaRetornar404() throws Exception {
        // Arrange
        Long id = 999L;
        when(productoService.obtenerProductoPorId(id)).thenReturn(Optional.empty());

        // Act & Assert
        mockMvc.perform(get("/api/productos/{id}", id))
                .andExpect(status().isNotFound());
    }

    @Test
    void crear_ConDatosValidos_DeberiaRetornar201() throws Exception {
        // Arrange
        ProductoDetalleDTO productoDTO = new ProductoDetalleDTO();
        productoDTO.setSku("CHAIR-001");
        productoDTO.setNombre("Silla Moderna");

        Producto producto = new Producto();
        when(productoService.crearProducto(any(ProductoDetalleDTO.class))).thenReturn(producto);
        when(productoMapper.toDTO(producto)).thenReturn(productoDTO);

        // Act & Assert
        mockMvc.perform(post("/api/productos")
                        .contentType(MediaType.APPLICATION_JSON)
                        .content(objectMapper.writeValueAsString(productoDTO)))
                .andExpect(status().isCreated())
                .andExpect(content().contentType(MediaType.APPLICATION_JSON));
    }

    @Test
    void eliminar_ConIdExistente_DeberiaRetornar204() throws Exception {
        // Arrange
        Long id = 1L;

        // Act & Assert
        mockMvc.perform(delete("/api/productos/{id}", id))
                .andExpect(status().isNoContent());
    }
}

@WebMvcTest only loads the web layer, making tests faster. Use @SpringBootTest for full integration tests.

Repository Testing

Test custom repository queries:

package com.edu.mcs.Iquea.repositories;

import com.edu.mcs.Iquea.models.Producto;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
import org.springframework.boot.test.autoconfigure.orm.jpa.TestEntityManager;

import java.math.BigDecimal;
import java.util.List;
import java.util.Optional;

import static org.assertj.core.api.Assertions.assertThat;

@DataJpaTest
class ProductoRepositoryTests {

    @Autowired
    private TestEntityManager entityManager;

    @Autowired
    private ProductoRepository productoRepository;

    @Test
    void findBySku_ConSkuExistente_DeberiaRetornarProducto() {
        // Arrange
        Producto producto = new Producto();
        producto.setSku("CHAIR-001");
        producto.setNombre("Silla Moderna");
        entityManager.persistAndFlush(producto);

        // Act
        Optional<Producto> resultado = productoRepository.findBySku("CHAIR-001");

        // Assert
        assertThat(resultado).isPresent();
        assertThat(resultado.get().getNombre()).isEqualTo("Silla Moderna");
    }

    @Test
    void existsBySku_ConSkuExistente_DeberiaRetornarTrue() {
        // Arrange
        Producto producto = new Producto();
        producto.setSku("CHAIR-001");
        entityManager.persistAndFlush(producto);

        // Act
        boolean existe = productoRepository.existsBySku("CHAIR-001");

        // Assert
        assertThat(existe).isTrue();
    }

    @Test
    void findByEs_destacado_DeberiaRetornarSoloDestacados() {
        // Arrange
        Producto destacado = new Producto();
        destacado.setSku("CHAIR-001");
        destacado.setEs_destacado(true);
        entityManager.persist(destacado);

        Producto normal = new Producto();
        normal.setSku("CHAIR-002");
        normal.setEs_destacado(false);
        entityManager.persist(normal);
        entityManager.flush();

        // Act
        List<Producto> destacados = productoRepository.findByEs_destacado(true);

        // Assert
        assertThat(destacados).hasSize(1);
        assertThat(destacados.get(0).isEs_destacado()).isTrue();
    }
}

Frontend Testing (React + TypeScript)

Testing Framework

The frontend can use:

Vitest - Fast unit test framework (Vite-native)
React Testing Library - Test React components
Jest - Alternative testing framework

Setting Up Tests

Install Testing Dependencies

cd Iquea_front
npm install -D vitest @testing-library/react @testing-library/jest-dom @testing-library/user-event jsdom

Configure Vitest

Update vite.config.ts:

import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'

export default defineConfig({
  plugins: [react()],
  test: {
    globals: true,
    environment: 'jsdom',
    setupFiles: './src/test/setup.ts',
  },
})

Add Test Script

Update package.json:

{
  "scripts": {
    "dev": "vite",
    "build": "tsc -b && vite build",
    "test": "vitest",
    "test:ui": "vitest --ui",
    "test:coverage": "vitest --coverage"
  }
}

Running Frontend Tests

# Run tests in watch mode
npm test

# Run tests once
npm test -- --run

# Run with UI
npm run test:ui

# Generate coverage report
npm run test:coverage

Component Testing

Test React components:

// src/components/ProductoCard.test.tsx
import { describe, it, expect } from 'vitest';
import { render, screen } from '@testing-library/react';
import { BrowserRouter } from 'react-router-dom';
import ProductoCard from './ProductoCard';
import type { Producto } from '../types';

const mockProducto: Producto = {
    producto_id: 1,
    sku: 'CHAIR-001',
    nombre: 'Silla Moderna',
    descripcion: 'Una silla cómoda',
    precioCantidad: 99.99,
    precioMoneda: 'EUR',
    dimensionesAlto: 100,
    dimensionesAncho: 50,
    dimensionesProfundo: 50,
    es_destacado: true,
    stock: 10,
    imagen_url: 'https://example.com/silla.jpg',
    categoria: {
        categoria_id: 1,
        nombre: 'Sillas',
        slug: 'sillas',
    },
};

const renderWithRouter = (component: React.ReactElement) => {
    return render(<BrowserRouter>{component}</BrowserRouter>);
};

describe('ProductoCard', () => {
    it('debería renderizar el nombre del producto', () => {
        renderWithRouter(<ProductoCard producto={mockProducto} />);
        expect(screen.getByText('Silla Moderna')).toBeInTheDocument();
    });

    it('debería mostrar el precio formateado', () => {
        renderWithRouter(<ProductoCard producto={mockProducto} />);
        expect(screen.getByText('99.99')).toBeInTheDocument();
        expect(screen.getByText('EUR')).toBeInTheDocument();
    });

    it('debería mostrar badge de destacado', () => {
        renderWithRouter(<ProductoCard producto={mockProducto} />);
        expect(screen.getByText('Destacado')).toBeInTheDocument();
    });

    it('debería renderizar imagen con alt text correcto', () => {
        renderWithRouter(<ProductoCard producto={mockProducto} />);
        const img = screen.getByAltText('Silla Moderna');
        expect(img).toHaveAttribute('src', 'https://example.com/silla.jpg');
    });

    it('debería mostrar categoría', () => {
        renderWithRouter(<ProductoCard producto={mockProducto} />);
        expect(screen.getByText('Sillas')).toBeInTheDocument();
    });

    it('debería mostrar badge de agotado cuando stock es 0', () => {
        const productoAgotado = { ...mockProducto, stock: 0 };
        renderWithRouter(<ProductoCard producto={productoAgotado} />);
        expect(screen.getByText('Agotado')).toBeInTheDocument();
    });
});

API Client Testing

Test API functions with mocked fetch:

// src/api/productos.test.ts
import { describe, it, expect, vi, beforeEach } from 'vitest';
import { fetchProductos, fetchProductoById } from './productos';
import type { Producto } from '../types';

global.fetch = vi.fn();

const mockProducto: Producto = {
    producto_id: 1,
    sku: 'CHAIR-001',
    nombre: 'Silla Moderna',
    // ... other fields
};

describe('API Productos', () => {
    beforeEach(() => {
        vi.clearAllMocks();
    });

    it('fetchProductos debería retornar lista de productos', async () => {
        const mockResponse = [mockProducto];
        (fetch as any).mockResolvedValueOnce({
            ok: true,
            json: async () => mockResponse,
        });

        const result = await fetchProductos();

        expect(fetch).toHaveBeenCalledWith(
            'http://localhost:8080/api/productos',
            expect.any(Object)
        );
        expect(result).toEqual(mockResponse);
    });

    it('fetchProductoById debería retornar producto por ID', async () => {
        (fetch as any).mockResolvedValueOnce({
            ok: true,
            json: async () => mockProducto,
        });

        const result = await fetchProductoById(1);

        expect(fetch).toHaveBeenCalledWith(
            'http://localhost:8080/api/productos/1',
            expect.any(Object)
        );
        expect(result).toEqual(mockProducto);
    });

    it('debería lanzar error cuando fetch falla', async () => {
        (fetch as any).mockResolvedValueOnce({
            ok: false,
            status: 404,
            json: async () => ({ message: 'Producto no encontrado' }),
        });

        await expect(fetchProductoById(999)).rejects.toThrow('Producto no encontrado');
    });
});

Test Coverage Goals

Aim for these coverage targets:

Service Layer: 80%+ coverage
Controllers: 70%+ coverage
Components: 70%+ coverage
Utilities: 90%+ coverage

Continuous Integration

Tests run automatically on:

Every push to feature branches
Pull request creation
Before merging to main

GitHub Actions Example

name: Tests

on: [push, pull_request]

jobs:
  backend-tests:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Set up JDK 21
        uses: actions/setup-java@v3
        with:
          java-version: '21'
      - name: Run tests
        run: |
          cd Iqüea_back
          ./mvnw test

  frontend-tests:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Setup Node.js
        uses: actions/setup-node@v3
        with:
          node-version: '18'
      - name: Install dependencies
        run: |
          cd Iquea_front
          npm install
      - name: Run tests
        run: npm test -- --run

Best Practices

General Testing Guidelines:

Write tests before fixing bugs (TDD for bug fixes)
Test edge cases and error conditions
Keep tests independent and isolated
Use meaningful test names
Don’t test implementation details
Mock external dependencies
Maintain fast test execution

What to Test:

Business logic in services
API endpoint contracts
Component rendering and interactions
Error handling and validation
Edge cases and boundary conditions

What NOT to Test:

Third-party library internals
Framework functionality
Getters/setters without logic
Generated code (MapStruct implementations)

Troubleshooting

Backend Test Issues

Tests fail with database connection errors:

# Use H2 in-memory database for tests
# Add to src/test/resources/application.properties:
spring.datasource.url=jdbc:h2:mem:testdb
spring.jpa.database-platform=org.hibernate.dialect.H2Dialect

MapStruct mapper not found:

# Rebuild project to regenerate mappers
./mvnw clean compile

Frontend Test Issues

Module resolution errors:

// Add to vite.config.ts
resolve: {
  alias: {
    '@': '/src',
  },
}

Async tests timing out:

// Increase timeout for slow tests
it('slow test', async () => {
  // ...
}, { timeout: 10000 }); // 10 seconds

Contributing

Deployment

Troubleshooting

Overview

Backend Testing (Spring Boot)

Testing Framework

Project Structure

Running Tests

Application Context Test

Unit Testing Services

Integration Testing Controllers

Repository Testing

Frontend Testing (React + TypeScript)

Testing Framework

Setting Up Tests

Running Frontend Tests

Component Testing

API Client Testing

Test Coverage Goals

Continuous Integration

GitHub Actions Example

Best Practices

Troubleshooting

Backend Test Issues

Frontend Test Issues

Additional Resources

Build docs developers (and LLMs) love

Contributing

Deployment

Troubleshooting

​Overview

​Backend Testing (Spring Boot)

​Testing Framework

​Project Structure

​Running Tests

​Application Context Test

​Unit Testing Services

​Integration Testing Controllers

​Repository Testing

​Frontend Testing (React + TypeScript)

​Testing Framework

​Setting Up Tests

​Running Frontend Tests

​Component Testing

​API Client Testing

​Test Coverage Goals

​Continuous Integration

​GitHub Actions Example

​Best Practices

​Troubleshooting

​Backend Test Issues

​Frontend Test Issues

​Additional Resources

Build docs developers (and LLMs) love

Overview

Backend Testing (Spring Boot)

Testing Framework

Project Structure

Running Tests

Application Context Test

Unit Testing Services

Integration Testing Controllers

Repository Testing

Frontend Testing (React + TypeScript)

Testing Framework

Setting Up Tests

Running Frontend Tests

Component Testing

API Client Testing

Test Coverage Goals

Continuous Integration

GitHub Actions Example

Best Practices

Troubleshooting

Backend Test Issues

Frontend Test Issues

Additional Resources