Connection between front and back

README.md

@@ -94,5 +94,5 @@ To run all back-end unit and integration tests (full code coverage):
     ```
 2.  Run the tests:
     ```bash
-
+    mvn test
     ```

backend/src/main/java/com/inventory/backend/config/WebConfig.java

@@ -0,0 +1,16 @@
+package com.inventory.backend.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.*;
+
+@Configuration
+public class WebConfig implements WebMvcConfigurer{
+    @Override
+    public void addCorsMappings(CorsRegistry registry){
+        registry.addMapping("/**")
+                .allowedOrigins("http://localhost:8080")
+                .allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS")
+                .allowedHeaders("*")
+                .allowCredentials(true);
+    }
+}

backend/src/main/java/com/inventory/backend/controller/ProductController.java

@@ -24,7 +24,7 @@ public ProductController(ProductService service) {
     @GetMapping
     public ProductPage getProducts(
             @RequestParam Optional<String> name,
-            @RequestParam Optional<List<String>> category,
+            @RequestParam Optional<String> category,
             @RequestParam Optional<Boolean> availability,
             @RequestParam Optional<String> sortBy,
             @RequestParam Optional<String> sortBy2,
@@ -33,10 +33,10 @@ public ProductPage getProducts(
             @RequestParam(defaultValue = "0") int page,
             @RequestParam(defaultValue = "10") int size
     ){
-        Set<String> categorySet = category.map(HashSet::new).orElse(null);
+        //Set<String> categorySet = category.map(HashSet::new).orElse(null);
         return service.getFilteredProductsPage(
                 name,
-                Optional.ofNullable(categorySet),
+                category,
                 availability,
                 sortBy,
                 sortBy2,

backend/src/main/java/com/inventory/backend/repository/ProductRepository.java

@@ -37,12 +37,12 @@ public void clear() {
 
     public List<Product> findByNameOrCategoryOrAvailability(
             Optional<String> nameFilter,
-            Optional<Set<String>> categoryFilter,
+            Optional<String> categoryFilter,
             Optional<Boolean> availability
     ) {
         return products.values().stream()
                 .filter(p -> nameFilter.map(name -> p.getName().toLowerCase().contains(name.toLowerCase())).orElse(true))
-                .filter(p -> categoryFilter.map(categories -> categories.contains(p.getCategory())).orElse(true))
+                .filter(p -> categoryFilter.filter(cat -> !cat.isBlank()).map(cat -> cat.equalsIgnoreCase(p.getCategory())).orElse(true))
                 .filter(p -> availability.map(avail -> avail == p.isInStock()).orElse(true))
                 .collect(Collectors.toList());
     }

backend/src/main/java/com/inventory/backend/service/ProductService.java

@@ -21,7 +21,7 @@ public ProductService(ProductRepository repository) {
 
     public List<Product> getFilteredAndSortedProducts(
             Optional<String> nameFilter,
-            Optional<Set<String>> categoryFilter,
+            Optional<String> categoryFilter,
             Optional<Boolean> availability,
             Optional<String> sortBy,
             Optional<String> sortBy2,
@@ -45,7 +45,7 @@ public List<Product> getFilteredAndSortedProducts(
     }
     public ProductPage getFilteredProductsPage(
             Optional<String> nameFilter,
-            Optional<Set<String>> categoryFilter,
+            Optional<String> categoryFilter,
             Optional<Boolean> availability,
             Optional<String> sortBy,
             Optional<String> sortBy2,

backend/src/test/java/com/inventory/backend/model/InventoryMetricsTest.java

@@ -0,0 +1,4 @@
+package com.inventory.backend.model;
+
+public class InventoryMetricsTest {
+}

backend/src/test/java/com/inventory/backend/service/ProductServiceTest.java

@@ -2,10 +2,15 @@
 
 import com.inventory.backend.dto.ProductDTO;
 import com.inventory.backend.model.Product;
+import com.inventory.backend.model.InventoryMetrics;
 import com.inventory.backend.repository.ProductRepository;
+import jakarta.validation.ConstraintViolation;
+import jakarta.validation.Validation;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
+import java.util.Optional;
+import java.util.Set;
 import java.util.UUID;
 
 import static org.junit.jupiter.api.Assertions.*;
@@ -52,4 +57,74 @@ void markOutOfStock_shouldSetQuantityToZero() {
         Product updated = repository.findById(id).orElseThrow();
         assertEquals(0, updated.getQuantityInStock());
     }
+
+    @Test
+    void shouldCalculateMetricsByCategory() {
+        ProductDTO dto = new ProductDTO();
+        dto.setName("Mouse");
+        dto.setCategory("Electronics");
+        dto.setUnitPrice(10.0);
+        dto.setQuantityInStock(5);
+        service.createProduct(dto);
+
+        ProductDTO dto2 = new ProductDTO();
+        dto2.setName("book");
+        dto2.setCategory("Books");
+        dto2.setUnitPrice(20.0);
+        dto2.setQuantityInStock(10);
+        service.createProduct(dto2);
+
+        InventoryMetrics metrics = service.getMetrics();
+        assertEquals(15, metrics.getTotalInStock());
+        assertTrue(metrics.getByCategory().containsKey("Books"));
+        assertTrue(metrics.getByCategory().containsKey("Electronics"));
+    }
+
+    @Test
+    void shouldFailValidationOnInvalidDTO() {
+        ProductDTO dto = new ProductDTO();
+        dto.setName("");
+        dto.setCategory("");
+        dto.setUnitPrice(-10.0);
+        dto.setQuantityInStock(-2);
+
+        Set<ConstraintViolation<ProductDTO>> violations = Validation.buildDefaultValidatorFactory()
+                .getValidator()
+                .validate(dto);
+
+        assertEquals(4, violations.size());
+    }
+
+    @Test
+    void shouldSortByNameAndStock() {
+        ProductDTO dto1 = new ProductDTO();
+        dto1.setName("AAA");
+        dto1.setCategory("Cat1");
+        dto1.setUnitPrice(10.0);
+        dto1.setQuantityInStock(5);
+
+        ProductDTO dto2 = new ProductDTO();
+        dto2.setName("AAA");
+        dto2.setCategory("Cat2");
+        dto2.setUnitPrice(20.0);
+        dto2.setQuantityInStock(2);
+
+        service.createProduct(dto1);
+        service.createProduct(dto2);
+
+        var result = service.getFilteredAndSortedProducts(
+                Optional.empty(),
+                Optional.empty(),
+                Optional.empty(),
+                Optional.of("name"),
+                Optional.of("quantityInStock"),
+                true,
+                false,
+                0,
+                10
+        );
+
+        assertEquals(5, result.get(0).getQuantityInStock());
+        assertEquals(2, result.get(1).getQuantityInStock());
+    }
 }

frontend/jest.config.js

@@ -0,0 +1,15 @@
+/** @type {import('ts-jest').JestConfigWithTsJest} */
+module.exports = {
+  preset: "ts-jest",
+  testEnvironment: "jsdom",
+  transform: {
+    "^.+\\.(ts|tsx)$": "ts-jest"
+  },
+  transformIgnorePatterns: [
+    "/node_modules/(?!(axios|react-icons)/)"
+  ],
+  moduleNameMapper: {
+    "\\.(css|less|scss|sass)$": "identity-obj-proxy"
+  },
+  setupFilesAfterEnv: ["<rootDir>/src/setupTests.ts"]
+};