added test for DayGenerator

src/test/java/fr/univ_amu/m1info/client/util/DayGeneratorTest.java

+package fr.univ_amu.m1info.client.util;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.time.LocalDate;
+import static org.assertj.core.api.Assertions.*;
+class DayGeneratorTest {
+    private static final LocalDate DATE_06_01_2025 = LocalDate.of(2025, 1, 6);
+    private static final LocalDate DATE_11_01_2025 = LocalDate.of(2025, 1, 11);
+    private static final LocalDate DATE_06_06_2026 = LocalDate.of(2026, 6, 6);
+    private static final LocalDate DATE_10_07_2026 = LocalDate.of(2026, 7, 10);
+    private DayGenerator generator06_01_to_11_01_2025;
+    private DayGenerator generator06_06_to_10_07_2026;
+
+    @BeforeEach
+    void setUp() {
+        generator06_01_to_11_01_2025 = new DayGenerator(new DateInterval(DATE_06_01_2025, DATE_11_01_2025));
+        generator06_06_to_10_07_2026 = new DayGenerator(new DateInterval(DATE_06_06_2026, DATE_10_07_2026));
+    }
+
+    @Test
+    void iterator() {
+    }
+
+    @Test
+    void getNumberOfDays() {
+        assertThat(generator06_01_to_11_01_2025.getNumberOfDays()).isEqualTo(5);
+        assertThat(generator06_06_to_10_07_2026.getNumberOfDays()).isEqualTo(34);
+    }
+
+    @Test
+    void getStartDate() {
+        assertThat(generator06_01_to_11_01_2025.getStartDate()).isEqualTo(DATE_06_01_2025);
+        assertThat(generator06_06_to_10_07_2026.getStartDate()).isEqualTo(DATE_06_06_2026);
+    }
+
+    @Test
+    void getEndDate() {
+        assertThat(generator06_06_to_10_07_2026.getEndDate()).isEqualTo(DATE_10_07_2026);
+        assertThat(generator06_01_to_11_01_2025.getEndDate()).isEqualTo(DATE_11_01_2025);
+    }
+
+    @Test
+    void getDayIndex() {
+        assertThat(generator06_01_to_11_01_2025.getDayIndex(LocalDate.of(2025, 1, 6)))
+                .isEqualTo(0);
+        assertThat(generator06_01_to_11_01_2025.getDayIndex(LocalDate.of(2025, 1, 8)))
+                .isEqualTo(2);
+        assertThat(generator06_06_to_10_07_2026.getDayIndex(LocalDate.of(2025, 1, 6)))
+                .isEqualTo(-1);
+    }
+
+    @Test
+    void testToString() {
+        assertThat(generator06_01_to_11_01_2025.toString())
+                .isEqualTo("DayGenerator{interval=DateInterval[start=2025-01-06, end=2025-01-11]}");
+    }
+}
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