Feat: add overwrite when 2 students have the same id and split tests

backend/model/tribe.py

@@ -8,6 +8,10 @@ if TYPE_CHECKING:
     from backend.model.student import Student
 
 
+class TribeError(Exception):
+    pass
+
+
 @dataclass
 class Tribe:
     name: str
@@ -18,7 +22,22 @@ class Tribe:
     def register_assessment(self, assessment: Assessment) -> None:
         self.assessments.append(assessment)
 
+    @property
+    def students_id(self) -> list[str]:
+        return [s.id for s in self.students]
+
     def register_student(self, student: Student) -> None:
+        """Register a student
+
+        If the student is already registered, it is modified.
+        """
+        try:
+            old_student = next(filter(lambda s: s.id == student.id, self.students))
+        except StopIteration:
+            pass
+        else:
+            self.students.remove(old_student)
+
         self.students.append(student)
 
     def __eq__(self, other: object) -> bool: