Feat: Added DonationSelect JavaDoc And Junit test

cathrkri · Apr 12, 2026 · c1c1b7f · c1c1b7f
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diff --git a/...application/src/main/java/ntnu/systemutvikling/team6/database/Readers/DonationSelect.java b/...application/src/main/java/ntnu/systemutvikling/team6/database/Readers/DonationSelect.java
@@ -9,13 +9,41 @@
 import ntnu.systemutvikling.team6.models.Donation;
 import ntnu.systemutvikling.team6.models.DonationRegistry;
 
+/**
+ * Data access class responsible for reading donation data from the database.
+ *
+ * <p>Retrieves donations along with their associated charity information by
+ * performing an INNER JOIN between the {@code Donations} and {@code Charities} tables.
+ * Only donations that have a matching charity record are returned.</p>
+ */
+
 public class DonationSelect {
+
+  /** The database connection used for all queries in this class. */
   private final DatabaseConnection connection;
 
+  /**
+   * Constructs a new {@code DonationSelect} with the given database connection.
+   *
+   * @param connection the {@link DatabaseConnection} to use for executing queries;
+   *                   must not be {@code null}
+   */
   public DonationSelect(DatabaseConnection connection) {
     this.connection = connection;
   }
 
+  /**
+   * Retrieves all donations from the database, each populated with its associated
+   * {@link Charity}.
+   *
+   * <p>The query performs an INNER JOIN between the {@code Donations} and
+   * {@code Charities} tables on the charity UUID foreign key. Donations without a
+   * matching charity are excluded from the result.</p>
+   *
+   * @return a {@link DonationRegistry} containing all matched donations;
+   *         never {@code null}, but may be empty if no rows are returned
+   * @throws RuntimeException if a {@link SQLException} occurs while executing the query
+   */
   public DonationRegistry getDonationFromDB() {
     DonationRegistry registry = null;
     Connection conn = null;

diff --git a/...ication/src/test/java/ntnu/systemutvikling/team6/database/Readers/DonationSelectTest.java b/...ication/src/test/java/ntnu/systemutvikling/team6/database/Readers/DonationSelectTest.java
@@ -0,0 +1,218 @@
+package ntnu.systemutvikling.team6.database.Readers;
+
+import ntnu.systemutvikling.team6.database.DatabaseConnection;
+import ntnu.systemutvikling.team6.models.Donation;
+import ntnu.systemutvikling.team6.models.DonationRegistry;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.Mock;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import java.sql.*;
+import java.time.LocalDate;
+
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.*;
+
+/**
+ * Unit tests for {@link DonationSelect}.
+ *
+ * <p>Uses Mockito to mock the entire JDBC stack so no real database
+ * connection is required.</p>
+ */
+@ExtendWith(MockitoExtension.class)
+class DonationSelectTest {
+
+    @Mock private DatabaseConnection mockDatabaseConnection;
+    @Mock private Connection         mockConnection;
+    @Mock private Statement          mockStatement;
+    @Mock private ResultSet          mockResultSet;
+    @Mock private Date               mockSqlDate;
+
+    private DonationSelect donationSelect;
+
+    @BeforeEach
+    void setUp() {
+        donationSelect = new DonationSelect(mockDatabaseConnection);
+    }
+
+    // -------------------------------------------------------------------------
+    // getDonationFromDB
+    // -------------------------------------------------------------------------
+
+    @Test
+    @DisplayName("getDonationFromDB – empty result set returns an empty registry")
+    void getDonationFromDB_emptyResultSet_returnsEmptyRegistry() throws Exception {
+        when(mockDatabaseConnection.getMySqlConnection()).thenReturn(mockConnection);
+        when(mockConnection.createStatement()).thenReturn(mockStatement);
+        when(mockStatement.executeQuery(anyString())).thenReturn(mockResultSet);
+        when(mockResultSet.next()).thenReturn(false);
+
+        DonationRegistry registry = donationSelect.getDonationFromDB();
+
+        assertNotNull(registry);
+        assertTrue(registry.getDonations().isEmpty(),
+                "Registry should be empty when the result set has no rows");
+    }
+
+    @Test
+    @DisplayName("getDonationFromDB – single row returns one Donation with correct data")
+    void getDonationFromDB_singleRow_returnsSingleDonation() throws Exception {
+        when(mockDatabaseConnection.getMySqlConnection()).thenReturn(mockConnection);
+        when(mockConnection.createStatement()).thenReturn(mockStatement);
+        when(mockStatement.executeQuery(anyString())).thenReturn(mockResultSet);
+
+        when(mockResultSet.next()).thenReturn(true, false);
+        stubCharityColumns("charity-uuid-1", "123456789", "Test Charity",
+                "https://example.org", true, "ACTIVE");
+        stubDonationColumns("donation-uuid-1", 250.0, LocalDate.of(2024, 5, 20));
+
+        DonationRegistry registry = donationSelect.getDonationFromDB();
+
+        assertEquals(1, registry.getDonations().size());
+        Donation donation = registry.getDonations().get(0);
+        assertEquals("donation-uuid-1", donation.getUUID());
+        assertEquals(250.0, donation.getAmount());
+        assertEquals(LocalDate.of(2024, 5, 20), donation.getDate());
+    }
+
+    @Test
+    @DisplayName("getDonationFromDB – single row maps charity fields onto the Donation correctly")
+    void getDonationFromDB_singleRow_charityMappedCorrectly() throws Exception {
+        when(mockDatabaseConnection.getMySqlConnection()).thenReturn(mockConnection);
+        when(mockConnection.createStatement()).thenReturn(mockStatement);
+        when(mockStatement.executeQuery(anyString())).thenReturn(mockResultSet);
+
+        when(mockResultSet.next()).thenReturn(true, false);
+        stubCharityColumns("charity-uuid-1", "987654321", "Help Fund",
+                "https://helpfund.org", false, "PENDING");
+        stubDonationColumns("donation-uuid-1", 100.0, LocalDate.of(2024, 1, 1));
+
+        DonationRegistry registry = donationSelect.getDonationFromDB();
+
+        Donation donation = registry.getDonations().get(0);
+        assertEquals("charity-uuid-1", donation.getCharity().getUUID());
+        assertEquals("987654321",      donation.getCharity().getOrgNumber());
+        assertEquals("Help Fund",      donation.getCharity().getCharityName());
+        assertEquals("https://helpfund.org", donation.getCharity().getCharityLink());
+        assertFalse(donation.getCharity().isPreApproved());
+        assertEquals("PENDING",        donation.getCharity().getStatus());
+    }
+
+    @Test
+    @DisplayName("getDonationFromDB – two rows returns two Donation objects")
+    void getDonationFromDB_twoRows_returnsTwoDonations() throws Exception {
+        when(mockDatabaseConnection.getMySqlConnection()).thenReturn(mockConnection);
+        when(mockConnection.createStatement()).thenReturn(mockStatement);
+        when(mockStatement.executeQuery(anyString())).thenReturn(mockResultSet);
+
+        when(mockResultSet.next()).thenReturn(true, true, false);
+
+        when(mockResultSet.getString("UUID_charities")).thenReturn("charity-uuid-1", "charity-uuid-2");
+        when(mockResultSet.getString("org_number")).thenReturn("111111111", "222222222");
+        when(mockResultSet.getString("charity_name")).thenReturn("Charity A", "Charity B");
+        when(mockResultSet.getString("charity_link")).thenReturn("https://a.org", "https://b.org");
+        when(mockResultSet.getBoolean("pre_approved")).thenReturn(true, false);
+        when(mockResultSet.getString("status")).thenReturn("ACTIVE", "INACTIVE");
+
+        when(mockResultSet.getString("UUID_Donations")).thenReturn("donation-uuid-1", "donation-uuid-2");
+        when(mockResultSet.getDouble("amount")).thenReturn(500.0, 750.0);
+
+        Date sqlDate = Date.valueOf(LocalDate.of(2024, 8, 10));
+        when(mockResultSet.getDate("date")).thenReturn(sqlDate);
+
+        DonationRegistry registry = donationSelect.getDonationFromDB();
+
+        assertEquals(2, registry.getDonations().size(),
+                "Registry should contain two donations for two result rows");
+    }
+
+    @Test
+    @DisplayName("getDonationFromDB – donation amount of zero is stored correctly")
+    void getDonationFromDB_zeroAmount_storedCorrectly() throws Exception {
+        when(mockDatabaseConnection.getMySqlConnection()).thenReturn(mockConnection);
+        when(mockConnection.createStatement()).thenReturn(mockStatement);
+        when(mockStatement.executeQuery(anyString())).thenReturn(mockResultSet);
+
+        when(mockResultSet.next()).thenReturn(true, false);
+        stubCharityColumns("charity-uuid-1", "123456789", "Test Charity",
+                "https://example.org", true, "ACTIVE");
+        stubDonationColumns("donation-uuid-zero", 0.0, LocalDate.of(2024, 1, 1));
+
+        DonationRegistry registry = donationSelect.getDonationFromDB();
+
+        assertEquals(0.0, registry.getDonations().get(0).getAmount());
+    }
+
+    @Test
+    @DisplayName("getDonationFromDB – large donation amount is stored correctly")
+    void getDonationFromDB_largeAmount_storedCorrectly() throws Exception {
+        when(mockDatabaseConnection.getMySqlConnection()).thenReturn(mockConnection);
+        when(mockConnection.createStatement()).thenReturn(mockStatement);
+        when(mockStatement.executeQuery(anyString())).thenReturn(mockResultSet);
+
+        when(mockResultSet.next()).thenReturn(true, false);
+        stubCharityColumns("charity-uuid-1", "123456789", "Test Charity",
+                "https://example.org", true, "ACTIVE");
+        stubDonationColumns("donation-uuid-big", 1_000_000.99, LocalDate.of(2024, 12, 31));
+
+        DonationRegistry registry = donationSelect.getDonationFromDB();
+
+        assertEquals(1_000_000.99, registry.getDonations().get(0).getAmount(), 0.001);
+    }
+
+    @Test
+    @DisplayName("getDonationFromDB – SQLException is wrapped in RuntimeException")
+    void getDonationFromDB_sqlException_throwsRuntimeException() throws Exception {
+        when(mockDatabaseConnection.getMySqlConnection()).thenReturn(mockConnection);
+        when(mockConnection.createStatement()).thenThrow(new SQLException("DB error"));
+
+        assertThrows(RuntimeException.class, () -> donationSelect.getDonationFromDB(),
+                "A SQLException should be rethrown as a RuntimeException");
+    }
+
+    @Test
+    @DisplayName("getDonationFromDB – RuntimeException message contains expected error text")
+    void getDonationFromDB_sqlException_runtimeExceptionHasExpectedMessage() throws Exception {
+        when(mockDatabaseConnection.getMySqlConnection()).thenReturn(mockConnection);
+        when(mockConnection.createStatement()).thenThrow(new SQLException("DB error"));
+
+        RuntimeException ex = assertThrows(RuntimeException.class,
+                () -> donationSelect.getDonationFromDB());
+        assertTrue(ex.getMessage().contains("ERROR"),
+                "RuntimeException message should contain 'ERROR'");
+    }
+
+    // -------------------------------------------------------------------------
+    // Helpers
+    // -------------------------------------------------------------------------
+
+    /**
+     * Stubs all charity-related columns on the mock ResultSet.
+     */
+    private void stubCharityColumns(String uuid, String orgNumber, String name,
+                                    String link, boolean preApproved, String status)
+            throws SQLException {
+        when(mockResultSet.getString("UUID_charities")).thenReturn(uuid);
+        when(mockResultSet.getString("org_number")).thenReturn(orgNumber);
+        when(mockResultSet.getString("charity_name")).thenReturn(name);
+        when(mockResultSet.getString("charity_link")).thenReturn(link);
+        when(mockResultSet.getBoolean("pre_approved")).thenReturn(preApproved);
+        when(mockResultSet.getString("status")).thenReturn(status);
+    }
+
+    /**
+     * Stubs all donation-related columns on the mock ResultSet.
+     */
+    private void stubDonationColumns(String uuid, double amount, LocalDate date)
+            throws SQLException {
+        when(mockResultSet.getString("UUID_Donations")).thenReturn(uuid);
+        when(mockResultSet.getDouble("amount")).thenReturn(amount);
+        Date sqlDate = Date.valueOf(date);
+        when(mockResultSet.getDate("date")).thenReturn(sqlDate);
+    }
+}