Added and rewrote tests

src/test/java/de/rwu/easydrop/service/processing/OfferIdentifierTest.java

@@ -1,5 +1,176 @@
 package de.rwu.easydrop.service.processing;
 
-public class OfferIdentifierTest {
-    
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import de.rwu.easydrop.exception.InvalidCatalogueException;
+import de.rwu.easydrop.exception.InvalidOfferException;
+import de.rwu.easydrop.model.Offer;
+import de.rwu.easydrop.model.Product;
+import de.rwu.easydrop.model.ProductCatalogue;
+import de.rwu.easydrop.model.ProductPair;
+
+class OfferIdentifierTest {
+
+    @Mock
+    private ProductCatalogue mockProductCatalogue;
+
+    private OfferIdentifier offerIdentifier;
+
+    @BeforeEach
+    void setUp() {
+        MockitoAnnotations.openMocks(this);
+
+        offerIdentifier = new OfferIdentifier();
+    }
+
+    @Test
+    void runIdentifier_WithValidProductCatalogues_IdentifiesOffers() {
+        // Arrange
+        List<ProductCatalogue> productCatalogues = new ArrayList<>();
+        ProductCatalogue productCatalogue1 = new ProductCatalogue("Catalogue1", "desc");
+        ProductCatalogue productCatalogue2 = new ProductCatalogue("Catalogue2", "desc");
+
+        Product product1 = new Product();
+        product1.setCurrentPrice(100.0);
+        Product product2 = new Product();
+        product2.setCurrentPrice(200.0);
+        Product product3 = new Product();
+        product3.setCurrentPrice(300.0);
+        Product product4 = new Product();
+        product4.setCurrentPrice(400.0);
+
+        productCatalogue1.addProduct(product1);
+        productCatalogue1.addProduct(product2);
+        productCatalogue2.addProduct(product3);
+        productCatalogue2.addProduct(product4);
+
+        productCatalogues.add(productCatalogue1);
+        productCatalogues.add(productCatalogue2);
+
+        // Act
+        List<Offer> identifiedOffers = offerIdentifier.runIdentifier(productCatalogues);
+
+        // Assert
+        assertEquals(2, identifiedOffers.size());
+        assertNotNull(identifiedOffers.get(0).getSourceProduct());
+        assertNotNull(identifiedOffers.get(0).getTargetProduct());
+        assertNotNull(identifiedOffers.get(1).getSourceProduct());
+        assertNotNull(identifiedOffers.get(1).getTargetProduct());
+    }
+
+    @Test
+    void runIdentifier_WithOneGoodOneBadCatalogue_BadOneIsntIncluded() {
+        // Arrange
+        List<ProductCatalogue> productCatalogues = new ArrayList<>();
+        ProductCatalogue productCatalogue1 = new ProductCatalogue("Catalogue1", "desc");
+        ProductCatalogue productCatalogue2 = new ProductCatalogue("Catalogue2", "desc");
+
+        Product product1 = new Product();
+        product1.setCurrentPrice(100.0);
+        Product product2 = new Product();
+        product2.setCurrentPrice(200.0);
+        Product product3 = new Product();
+        product3.setCurrentPrice(300.0);
+        Product product4 = new Product();
+        product4.setCurrentPrice(300.0);
+
+        productCatalogue1.addProduct(product1);
+        productCatalogue1.addProduct(product2);
+        productCatalogue2.addProduct(product3);
+        productCatalogue2.addProduct(product4);
+
+        productCatalogues.add(productCatalogue1);
+        productCatalogues.add(productCatalogue2);
+
+        // Act
+        List<Offer> identifiedOffers = offerIdentifier.runIdentifier(productCatalogues);
+
+        // Assert
+        assertEquals(1, identifiedOffers.size()); // Only 1 passed
+    }
+
+    @Test
+    void getHighestMarginProducts_WithValidProductCatalogue_ReturnsProductPair() {
+        // Arrange
+        ProductCatalogue productCatalogue = new ProductCatalogue("TestCatalogue", "desc");
+        Product product1 = new Product();
+        product1.setCurrentPrice(100.0);
+        Product product2 = new Product();
+        product2.setCurrentPrice(200.0);
+        productCatalogue.addProduct(product1);
+        productCatalogue.addProduct(product2);
+
+        // Act
+        ProductPair productPair = OfferIdentifier.getHighestMarginProducts(productCatalogue);
+
+        // Assert
+        assertNotNull(productPair);
+        assertNotNull(productPair.getProduct1());
+        assertNotNull(productPair.getProduct2());
+        assertNotEquals(productPair.getProduct1(), productPair.getProduct2());
+    }
+
+    @Test
+    void getHighestMarginProducts_SecondProductCheaper() {
+        // Arrange
+        ProductCatalogue productCatalogue = new ProductCatalogue("TestCatalogue", "desc");
+        Product product1 = new Product();
+        product1.setCurrentPrice(200.0);
+        Product product2 = new Product();
+        product2.setCurrentPrice(100.0);
+        productCatalogue.addProduct(product1);
+        productCatalogue.addProduct(product2);
+
+        // Act
+        ProductPair productPair = OfferIdentifier.getHighestMarginProducts(productCatalogue);
+
+        // Assert
+        assertNotNull(productPair);
+        assertNotNull(productPair.getProduct1());
+        assertNotNull(productPair.getProduct2());
+        assertNotEquals(productPair.getProduct1(), productPair.getProduct2());
+    }
+
+    @Test
+    void getHighestMarginProducts_WithCatalogueSizeLessThan2_ThrowsInvalidCatalogueException() {
+        // Arrange
+        ProductCatalogue productCatalogue = new ProductCatalogue("SmallCatalogue", "desc");
+
+        // Act and Assert
+        assertThrows(InvalidCatalogueException.class, () -> {
+            OfferIdentifier.getHighestMarginProducts(productCatalogue);
+        });
+    }
+
+    @Test
+    void getHighestMarginProducts_WithZeroPriceMargin_ThrowsInvalidOfferException() {
+        // Arrange
+        ProductCatalogue productCatalogue = new ProductCatalogue("name", "desc");
+        Product product1 = new Product();
+        product1.setCurrentPrice(200.0);
+
+        Product product2 = new Product();
+        product2.setCurrentPrice(200.0);
+
+        productCatalogue.getProducts().add(product1);
+        productCatalogue.getProducts().add(product2);
+
+        // Act and Assert
+        InvalidOfferException e = assertThrows(InvalidOfferException.class, () -> {
+            OfferIdentifier.getHighestMarginProducts(productCatalogue);
+        });
+
+        assertEquals("Price margin is zero!", e.getMessage());
+    }
 }