Added Product mapping and validation

src/test/java/de/rwu/easydrop/service/mapping/ProductMapperTest.java

@@ -0,0 +1,56 @@
+package de.rwu.easydrop.service.mapping;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Modifier;
+
+import org.junit.jupiter.api.Test;
+
+import de.rwu.easydrop.api.dto.ProductDTO;
+import de.rwu.easydrop.model.Product;
+
+class ProductMapperTest {
+    @Test
+    void testConstructorIsPrivate()
+            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
+        // Check for private constructor
+        Constructor<ProductMapper> constructor = ProductMapper.class.getDeclaredConstructor();
+        assertTrue(Modifier.isPrivate(constructor.getModifiers()));
+
+        // Make sure exception is thrown when instantiating
+        constructor.setAccessible(true);
+        assertThrows(InvocationTargetException.class, () -> {
+            constructor.newInstance();
+        });
+    }
+
+    @Test
+    void mapProductFromDTO_ReturnsProductWithMappedFields() {
+        // Arrange
+        ProductDTO dto = createProductDTO();
+
+        // Act
+        Product product = ProductMapper.mapProductFromDTO(dto);
+
+        // Assert
+        assertEquals(dto.isAvailable(), product.isAvailable());
+        assertEquals(dto.getCurrentPrice(), product.getCurrentPrice());
+        assertEquals(dto.getDataOrigin(), product.getDataOrigin());
+        assertEquals(dto.getDeliveryPrice(), product.getDeliveryPrice());
+        assertEquals(dto.getMerchant(), product.getMerchant());
+        assertEquals(dto.getProductId(), product.getProductId());
+    }
+
+    private ProductDTO createProductDTO() {
+        ProductDTO dto = new ProductDTO("12345", "Amazon");
+        dto.setAvailable(true);
+        dto.setCurrentPrice(9.99);
+        dto.setDeliveryPrice(2.50);
+        dto.setMerchant("Example Merchant");
+        return dto;
+    }
+}

src/test/java/de/rwu/easydrop/service/validation/ProductValidatorTest.java

@@ -0,0 +1,109 @@
+package de.rwu.easydrop.service.validation;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Modifier;
+import java.util.stream.Stream;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+
+import de.rwu.easydrop.exception.InvalidProductException;
+import de.rwu.easydrop.model.Product;
+
+class ProductValidatorTest {
+
+    @Test
+    void testConstructorIsPrivate()
+            throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
+        // Check for private constructor
+        Constructor<ProductValidator> constructor = ProductValidator.class.getDeclaredConstructor();
+        assertTrue(Modifier.isPrivate(constructor.getModifiers()));
+
+        // Make sure exception is thrown when instantiating
+        constructor.setAccessible(true);
+        assertThrows(InvocationTargetException.class, () -> {
+            constructor.newInstance();
+        });
+    }
+
+    @Test
+    void validate_ValidProduct_NoExceptionThrown() {
+        // Arrange
+        Product product = new Product();
+        product.setCurrentPrice(9.99);
+        product.setDataOrigin("Amazon");
+        product.setProductId("12345");
+
+        // Act and Assert
+        assertDoesNotThrow(() -> ProductValidator.validate(product));
+    }
+
+    @Test
+    void isInValidDataOrigins_ValidDataOrigin_ReturnsTrue() {
+        // Arrange
+        String dataOrigin = "Amazon";
+
+        // Act
+        boolean result = ProductValidator.isInValidDataOrigins(dataOrigin);
+
+        // Assert
+        assertTrue(result);
+    }
+
+    @Test
+    void isInValidDataOrigins_InvalidDataOrigin_ReturnsFalse() {
+        // Arrange
+        String dataOrigin = "UnknownOrigin";
+
+        // Act
+        boolean result = ProductValidator.isInValidDataOrigins(dataOrigin);
+
+        // Assert
+        assertFalse(result);
+    }
+
+    @ParameterizedTest
+    @MethodSource("invalidProductProvider")
+    void validate_InvalidProduct_ThrowsInvalidProductException(Product product) {
+        // Act and Assert
+        assertThrows(InvalidProductException.class, () -> ProductValidator.validate(product));
+    }
+
+    static Stream<Product> invalidProductProvider() {
+        return Stream.of(
+                createProductWithZeroPrice(),
+                createProductWithUnknownDataOrigin(),
+                createProductWithEmptyProductId());
+    }
+
+    private static Product createProductWithZeroPrice() {
+        Product product = new Product();
+        product.setCurrentPrice(0.00);
+        product.setDataOrigin("Amazon");
+        product.setProductId("12345");
+        return product;
+    }
+
+    private static Product createProductWithUnknownDataOrigin() {
+        Product product = new Product();
+        product.setCurrentPrice(9.99);
+        product.setDataOrigin("UnknownOrigin");
+        product.setProductId("12345");
+        return product;
+    }
+
+    private static Product createProductWithEmptyProductId() {
+        Product product = new Product();
+        product.setCurrentPrice(9.99);
+        product.setDataOrigin("Amazon");
+        product.setProductId("");
+        return product;
+    }
+}