test: deleteAdmin method in Administration class

src/test/java/org/example/AdministrationTest.java

@@ -60,6 +60,39 @@ class AdministrationTest {
         assertEquals(false, test02);
         assertEquals(false, test03);
     }
+
+    @Test
+    void deleteAdmin() {
+        // Create an instance of Administration
+        Administration administration = new Administration();
+
+        // Create some sample admins
+        Admin admin1 = new Admin("Saul Goodman", "A123456", "Admin");
+        Admin admin2 = new Admin("Mike Unknown", "A789012", "Admin");
+
+        // Add admins to the administration
+        administration.addAdmin(admin1);
+        administration.addAdmin(admin2);
+
+        // Attempt to delete an admin (admin1)
+        boolean deleted = administration.deleteAdmin("A123456");
+
+        // Check if the admin is deleted successfully
+        assertTrue(deleted);
+
+        // Check if the admin is no longer in the system
+        assertNull(administration.findAdminById("A123456"));
+
+        // Check if the other admin (admin2) still exists in the system
+        assertNotNull(administration.findAdminById("A789012"));
+
+        // Attempt to delete a non-existing admin
+        boolean nonExistingAdminDeleted = administration.deleteAdmin("A999999");
+
+        // Check if the deletion of non-existing admin returns false
+        assertFalse(nonExistingAdminDeleted);
+    }
+
 @org.junit.jupiter.api.Test
 
     void findStudentById(){