fix(M3): immuabilité et validation des modèles — correction des écarts FIXME_M3

Immuabilité :
- Collections des modèles frozen : list → tuple (Lesson, TheoreticalLesson,
  SchoolEvent, AgendaDiff, Homework, XmppMessage, ExternalInfo)
- Gel de HomeworkBlock et ExternalInfo (sous-modèles imbriqués dans contrats)
- Valeurs par défaut immuables : Field(default=(), ...)

Validation de domaine :
- TheoreticalLesson.day_of_week : Field(ge=0, le=6)
- Lesson/TheoreticalLesson : start < end (validateur de modèle)
- SchoolEvent : from_date <= to_date
- AgendaChange : cohérence type/payload (ADDED/MODIFIED → lesson,
  REMOVED → theoretical_lesson)
- CalDAVSyncResult : compteurs Field(ge=0) sur added/updated/removed

Tests : 66 tests (construction/sérialisation, immuabilité, invariants)
couvrant le gel, la mutabilité légitime, et les cas invalides par invariant.

Co-authored-by: opencode/coder <coder@agents.invalid>
Co-authored-by: opencode/test-engineer <test-engineer@agents.invalid>

pronote_sync/models/agenda.py

@@ -8,7 +8,7 @@ from datetime import time as _time
 from enum import StrEnum
 from typing import Literal
 
-from pydantic import BaseModel, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, Field, model_validator
 
 
 class Status(StrEnum):
@@ -30,6 +30,8 @@ class LessonStatus(StrEnum):
 class HomeworkBlock(BaseModel):
     """Représente un bloc de devoir extrait de la description d'un cours."""
 
+    model_config = ConfigDict(frozen=True)
+
     kind: Literal["due", "assigned"] = Field(
         ..., description="Type de bloc (échéance ou attribution)"
     )
@@ -47,16 +49,28 @@ class Lesson(BaseModel):
     start: datetime = Field(..., description="Date/heure de début")
     end: datetime = Field(..., description="Date/heure de fin")
     subject: str = Field(..., description="Matière")
-    teachers: list[str] = Field(default_factory=list, description="Liste des professeurs")
-    rooms: list[str] = Field(default_factory=list, description="Liste des salles")
+    teachers: tuple[str, ...] = Field(default=(), description="Liste des professeurs")
+    rooms: tuple[str, ...] = Field(default=(), description="Liste des salles")
     group: str | None = Field(None, description="Groupe (ex: Classe entière)")
     status: LessonStatus = Field(default=LessonStatus.NORMAL, description="Statut du cours")
     content: str | None = Field(None, description="Contenu pédagogique")
-    homework_blocks: list[HomeworkBlock] = Field(
-        default_factory=list,
+    homework_blocks: tuple[HomeworkBlock, ...] = Field(
+        default=(),
         description="Blocs de devoirs extraits de la description",
     )
 
+    @model_validator(mode="after")
+    def _validate_time_order(self) -> Lesson:
+        """Valide que l'heure de fin est postérieure à l'heure de début.
+
+        :return: L'instance validée.
+        :rtype: Lesson
+        :raises ValueError: Si ``end`` n'est pas postérieur à ``start``.
+        """
+        if self.end <= self.start:
+            raise ValueError("end doit être postérieur à start")
+        return self
+
 
 class SchoolEventKind(StrEnum):
     """Type d'événement scolaire."""
@@ -75,6 +89,18 @@ class SchoolEvent(BaseModel):
     from_date: _date = Field(..., description="Date de début (inclusive)")
     to_date: _date = Field(..., description="Date de fin (exclusive)")
 
+    @model_validator(mode="after")
+    def _validate_date_order(self) -> SchoolEvent:
+        """Valide que la date de fin est postérieure ou égale à la date de début.
+
+        :return: L'instance validée.
+        :rtype: SchoolEvent
+        :raises ValueError: Si ``to_date`` est antérieur à ``from_date``.
+        """
+        if self.to_date < self.from_date:
+            raise ValueError("to_date doit être postérieur ou égal à from_date")
+        return self
+
 
 class TheoreticalLesson(BaseModel):
     """Représente un cours dans l'agenda théorique."""
@@ -82,9 +108,23 @@ class TheoreticalLesson(BaseModel):
     model_config = ConfigDict(frozen=True)
 
     id: str = Field(..., description="Identifiant unique")
-    day_of_week: int = Field(..., description="Jour de la semaine (0=lundi, 6=dimanche)")
+    day_of_week: int = Field(
+        ..., ge=0, le=6, description="Jour de la semaine (0=lundi, 6=dimanche)"
+    )
     start_time: _time = Field(..., description="Heure de début")
     end_time: _time = Field(..., description="Heure de fin")
     subject: str = Field(..., description="Matière")
-    teachers: list[str] = Field(default_factory=list, description="Liste des professeurs")
-    rooms: list[str] = Field(default_factory=list, description="Liste des salles")
+    teachers: tuple[str, ...] = Field(default=(), description="Liste des professeurs")
+    rooms: tuple[str, ...] = Field(default=(), description="Liste des salles")
+
+    @model_validator(mode="after")
+    def _validate_time_order(self) -> TheoreticalLesson:
+        """Valide que l'heure de fin est postérieure à l'heure de début.
+
+        :return: L'instance validée.
+        :rtype: TheoreticalLesson
+        :raises ValueError: Si ``end_time`` n'est pas postérieur à ``start_time``.
+        """
+        if self.end_time <= self.start_time:
+            raise ValueError("end_time doit être postérieur à start_time")
+        return self

pronote_sync/models/blog.py

@@ -26,17 +26,22 @@ class BlogArticle(BaseModel):
 
 
 class ExternalInfo(BaseModel):
-    """Agrège les informations externes (blog, messages Pronote) pour le message XMPP."""
+    """Agrège les informations externes (blog, messages Pronote) pour le message XMPP.
 
-    blog_articles: list[BlogArticle] = Field(
-        default_factory=list,
+    Modèle figé (``frozen``) : les instances sont immuables après création.
+    """
+
+    model_config = ConfigDict(frozen=True)
+
+    blog_articles: tuple[BlogArticle, ...] = Field(
+        default=(),
         description="Liste des nouveaux articles du blog",
     )
-    pronote_messages: list[Message] = Field(
-        default_factory=list,
+    pronote_messages: tuple[Message, ...] = Field(
+        default=(),
         description="Liste des messages Pronote",
     )
-    other_info: list[str] = Field(
-        default_factory=list,
+    other_info: tuple[str, ...] = Field(
+        default=(),
         description="Autres informations (extensible)",
     )

pronote_sync/models/diff.py

@@ -5,7 +5,7 @@ from __future__ import annotations
 from datetime import date
 from enum import StrEnum
 
-from pydantic import BaseModel, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, Field, model_validator
 
 from pronote_sync.models.agenda import Lesson, TheoreticalLesson
 
@@ -30,6 +30,22 @@ class AgendaChange(BaseModel):
     )
     details: str = Field(default="", description="Détails du changement")
 
+    @model_validator(mode="after")
+    def _validate_payload_consistency(self) -> AgendaChange:
+        """Valide la cohérence entre le type de changement et le payload.
+
+        :return: L'instance validée.
+        :rtype: AgendaChange
+        :raises ValueError: Si le payload ne correspond pas au type de changement.
+        """
+        if self.type in (AgendaChangeType.ADDED, AgendaChangeType.MODIFIED):
+            if self.lesson is None:
+                raise ValueError(f"lesson est requis pour le type {self.type!r}")
+        if self.type == AgendaChangeType.REMOVED:
+            if self.theoretical_lesson is None:
+                raise ValueError(f"theoretical_lesson est requis pour le type {self.type!r}")
+        return self
+
 
 class AgendaDiff(BaseModel):
     """Représente les différences entre l'agenda réel et l'agenda théorique."""
@@ -37,4 +53,4 @@ class AgendaDiff(BaseModel):
     model_config = ConfigDict(frozen=True)
 
     target_date: date = Field(..., description="Date cible de la comparaison")
-    changes: list[AgendaChange] = Field(default_factory=list, description="Liste des changements")
+    changes: tuple[AgendaChange, ...] = Field(default=(), description="Liste des changements")

pronote_sync/models/homework.py

@@ -14,7 +14,7 @@ class Homework(BaseModel):
 
     id: str = Field(..., description="ID stable (hachage)")
     subject: str = Field(..., description="Matière")
-    teachers: list[str] = Field(default_factory=list, description="Liste des professeurs")
+    teachers: tuple[str, ...] = Field(default=(), description="Liste des professeurs")
     assigned_on: date | None = Field(None, description="Date de distribution")
     due_on: date = Field(..., description="Date d'échéance")
     text: str = Field(..., description="Texte du devoir (brut)")

pronote_sync/models/sync.py

@@ -36,7 +36,7 @@ class CalDAVSyncResult(BaseModel):
     """Résultat d'une synchronisation CalDAV (mutable)."""
 
     status: CalDAVSyncStatus = Field(..., description="Statut global")
-    added: int = Field(0, description="Nombre d'événements ajoutés")
-    updated: int = Field(0, description="Nombre d'événements mis à jour")
-    removed: int = Field(0, description="Nombre d'événements supprimés")
+    added: int = Field(0, ge=0, description="Nombre d'événements ajoutés")
+    updated: int = Field(0, ge=0, description="Nombre d'événements mis à jour")
+    removed: int = Field(0, ge=0, description="Nombre d'événements supprimés")
     errors: list[str] = Field(default_factory=list, description="Liste des erreurs")

pronote_sync/models/xmpp.py

@@ -19,13 +19,11 @@ class XmppMessage(BaseModel):
 
     target_date: date = Field(..., description="Date cible")
     synthesis: str | None = Field(None, description="Synthèse IA (optionnelle, 3-5 phrases)")
-    homeworks: list[Homework] = Field(default_factory=list, description="Liste brute des devoirs")
-    changes: list[AgendaChange] = Field(
-        default_factory=list, description="Liste des changements d'agenda"
-    )
-    messages: list[Message] = Field(
-        default_factory=list, description="Liste des messages/informations"
+    homeworks: tuple[Homework, ...] = Field(default=(), description="Liste brute des devoirs")
+    changes: tuple[AgendaChange, ...] = Field(
+        default=(), description="Liste des changements d'agenda"
     )
+    messages: tuple[Message, ...] = Field(default=(), description="Liste des messages/informations")
     external_info: ExternalInfo | None = Field(
         None, description="Informations externes (blog, messages Pronote)"
     )

tests/unit/test_models_construction.py

@@ -0,0 +1,373 @@
+"""Tests de construction et sérialisation JSON des modèles Pydantic.
+
+Ce module vérifie que chaque modèle figé peut être sérialisé en JSON puis désérialisé
+sans perte de données, garantissant la stabilité des contrats d'échange.
+
+Les tests utilisent des données minimales valides extraites des définitions de modèles.
+"""
+
+from __future__ import annotations
+
+from datetime import date, datetime, time
+from typing import Any
+
+import pytest
+from pydantic import BaseModel
+
+from pronote_sync.models.agenda import (
+    HomeworkBlock,
+    Lesson,
+    LessonStatus,
+    SchoolEvent,
+    SchoolEventKind,
+    TheoreticalLesson,
+)
+from pronote_sync.models.blog import BlogArticle, ExternalInfo
+from pronote_sync.models.diff import AgendaChange, AgendaChangeType, AgendaDiff
+from pronote_sync.models.homework import Homework
+from pronote_sync.models.message import Message, MessageType
+from pronote_sync.models.xmpp import XmppMessage
+
+
+@pytest.mark.parametrize(
+    "model_class, kwargs",
+    [
+        (
+            Lesson,
+            {
+                "id": "lesson-001",
+                "start": datetime(2024, 9, 6, 8, 0, 0),
+                "end": datetime(2024, 9, 6, 9, 30, 0),
+                "subject": "Mathématiques",
+                "teachers": ("M. Dupont",),
+                "rooms": ("Salle 101",),
+                "group": "Classe A",
+                "status": LessonStatus.NORMAL,
+                "content": "Algèbre linéaire",
+                "homework_blocks": (
+                    HomeworkBlock(kind="due", date=date(2024, 9, 13), text="Exercice 42"),
+                ),
+            },
+        ),
+        (
+            TheoreticalLesson,
+            {
+                "id": "theo-lesson-001",
+                "day_of_week": 0,  # Lundi
+                "start_time": time(8, 0, 0),
+                "end_time": time(9, 30, 0),
+                "subject": "Mathématiques",
+                "teachers": ("M. Dupont",),
+                "rooms": ("Salle 101",),
+            },
+        ),
+        (
+            SchoolEvent,
+            {
+                "kind": SchoolEventKind.HOLIDAY,
+                "label": "Vacances de la Toussaint",
+                "from_date": date(2024, 10, 19),
+                "to_date": date(2024, 11, 3),
+            },
+        ),
+        (
+            Homework,
+            {
+                "id": "hw-001",
+                "subject": "Mathématiques",
+                "teachers": ("M. Dupont",),
+                "assigned_on": date(2024, 9, 1),
+                "due_on": date(2024, 9, 15),
+                "text": "Exercice 42 à rendre",
+                "html": "<p>Exercice 42 à rendre</p>",
+            },
+        ),
+        (
+            AgendaChange,
+            {
+                "type": AgendaChangeType.ADDED,
+                "lesson": Lesson(
+                    id="lesson-002",
+                    start=datetime(2024, 9, 7, 10, 0, 0),
+                    end=datetime(2024, 9, 7, 11, 30, 0),
+                    subject="Physique",
+                    teachers=("M. Martin",),
+                    rooms=("Labo 205",),
+                    group=None,
+                    content=None,
+                ),
+                "theoretical_lesson": None,
+                "details": "Cours ajouté exceptionnellement",
+            },
+        ),
+        (
+            AgendaDiff,
+            {
+                "target_date": date(2024, 9, 6),
+                "changes": (
+                    AgendaChange(
+                        type=AgendaChangeType.ADDED,
+                        lesson=Lesson(
+                            id="lesson-003",
+                            start=datetime(2024, 9, 8, 14, 0, 0),
+                            end=datetime(2024, 9, 8, 15, 30, 0),
+                            subject="Histoire",
+                            teachers=("Mme Bernard",),
+                            rooms=("Salle 201",),
+                            group=None,
+                            content=None,
+                        ),
+                        theoretical_lesson=None,
+                    ),
+                ),
+            },
+        ),
+        (
+            XmppMessage,
+            {
+                "target_date": date(2024, 9, 6),
+                "synthesis": "Aucun changement majeur aujourd'hui.",
+                "homeworks": (
+                    Homework(
+                        id="hw-002",
+                        subject="Physique",
+                        teachers=("M. Martin",),
+                        assigned_on=None,
+                        due_on=date(2024, 9, 7),
+                        text="TP à préparer",
+                    ),
+                ),
+                "changes": (
+                    AgendaChange(
+                        type=AgendaChangeType.MODIFIED,
+                        lesson=Lesson(
+                            id="lesson-004",
+                            start=datetime(2024, 9, 6, 16, 0, 0),
+                            end=datetime(2024, 9, 6, 17, 30, 0),
+                            subject="SVT",
+                            teachers=("M. Lefèvre",),
+                            rooms=("Salle 302",),
+                            group=None,
+                            content=None,
+                        ),
+                        theoretical_lesson=None,
+                    ),
+                ),
+                "messages": (
+                    Message(
+                        id="msg-001",
+                        type=MessageType.INFORMATION,
+                        title="Rappel",
+                        content="Réunion parents-professeurs demain",
+                        author="Secrétariat",
+                        date=datetime(2024, 9, 5, 10, 0, 0),
+                        read=False,
+                    ),
+                ),
+                "external_info": ExternalInfo(blog_articles=(), pronote_messages=(), other_info=()),
+            },
+        ),
+        (
+            BlogArticle,
+            {
+                "id": "article-001",
+                "title": "Sortie scolaire à Paris",
+                "url": "https://college.fr/blog/sortie-paris",
+                "published_at": datetime(2024, 9, 5, 14, 30, 0),
+                "updated_at": datetime(2024, 9, 5, 16, 45, 0),
+                "category": "Actualités",
+                "author": "M. Dubois",
+                "content_html": "<p>Sortie prévue le 15 octobre</p>",
+                "content_text": "Sortie prévue le 15 octobre",
+            },
+        ),
+        (
+            ExternalInfo,
+            {
+                "blog_articles": (
+                    BlogArticle(
+                        id="article-002",
+                        title="Nouveau règlement intérieur",
+                        url="https://college.fr/blog/reglement",
+                        published_at=datetime(2024, 9, 1, 9, 0, 0),
+                        updated_at=None,
+                        category=None,
+                        author=None,
+                        content_html="<p>Mise à jour du règlement</p>",
+                        content_text="Mise à jour du règlement",
+                    ),
+                ),
+                "pronote_messages": (
+                    Message(
+                        id="msg-002",
+                        type=MessageType.DISCUSSION,
+                        title="Devoirs de maths",
+                        content="Voir Pronote pour les détails",
+                        author="Prof Maths",
+                        date=datetime(2024, 9, 4, 8, 0, 0),
+                        read=False,
+                    ),
+                ),
+                "other_info": ("Info complémentaire 1", "Info complémentaire 2"),
+            },
+        ),
+        (
+            Message,
+            {
+                "id": "msg-003",
+                "type": MessageType.SURVEY,
+                "title": "Enquête de satisfaction",
+                "content": "Merci de répondre au questionnaire",
+                "author": "Direction",
+                "date": datetime(2024, 9, 5, 11, 0, 0),
+                "read": False,
+            },
+        ),
+    ],
+)
+def test_model_json_roundtrip(model_class: type[BaseModel], kwargs: dict[str, Any]) -> None:
+    """Vérifie qu'un modèle peut être sérialisé en JSON puis désérialisé sans perte.
+
+    :param model_class: Classe du modèle à tester.
+    :type model_class: type[BaseModel]
+    :param kwargs: Arguments de constructeur valides.
+    :type kwargs: dict[str, Any]
+    """
+    # Construction de l'instance
+    instance = model_class(**kwargs)
+
+    # Sérialisation JSON
+    json_str = instance.model_dump_json()
+
+    # Désérialisation depuis JSON
+    roundtrip_instance = model_class.model_validate_json(json_str)
+
+    # Vérification des champs clés (comparaison par valeur)
+    for field_name in kwargs:
+        if field_name in (
+            "start",
+            "end",
+            "start_time",
+            "end_time",
+            "published_at",
+            "updated_at",
+            "date",
+            "due_on",
+            "assigned_on",
+            "generated_at",
+        ):
+            # Pour les dates/heures, comparer les objets directement
+            assert getattr(instance, field_name) == getattr(roundtrip_instance, field_name), (
+                f"Le champ {field_name} ne correspond pas après round-trip"
+            )
+        else:
+            # Pour les autres champs, comparer directement
+            assert getattr(instance, field_name) == getattr(roundtrip_instance, field_name), (
+                f"Le champ {field_name} ne correspond pas après round-trip"
+            )
+
+
+def test_lesson_status_enum_values() -> None:
+    """Vérifie que les valeurs de l'enum LessonStatus sont correctes.
+
+    :raises ValidationError: Si une valeur invalide est utilisée.
+    """
+    # Test des valeurs valides
+    for status in [LessonStatus.NORMAL, LessonStatus.CANCELLED, LessonStatus.MOVED]:
+        assert isinstance(status.value, str)
+        Lesson(
+            id="test",
+            start=datetime(2024, 9, 6, 8, 0),
+            end=datetime(2024, 9, 6, 9, 0),
+            subject="Test",
+            status=status,
+            group=None,
+            content=None,
+        )
+
+
+def test_school_event_kind_enum_values() -> None:
+    """Vérifie que les valeurs de l'enum SchoolEventKind sont correctes.
+
+    :raises ValidationError: Si une valeur invalide est utilisée.
+    """
+    # Test des valeurs valides
+    for kind in [SchoolEventKind.HOLIDAY, SchoolEventKind.PUBLIC_HOLIDAY]:
+        assert isinstance(kind.value, str)
+        SchoolEvent(
+            kind=kind,
+            label="Test",
+            from_date=date(2024, 9, 1),
+            to_date=date(2024, 9, 2),
+        )
+
+
+def test_message_type_enum_values() -> None:
+    """Vérifie que les valeurs de l'enum MessageType sont correctes.
+
+    :raises ValidationError: Si une valeur invalide est utilisée.
+    """
+    # Test des valeurs valides
+    for msg_type in [MessageType.DISCUSSION, MessageType.INFORMATION, MessageType.SURVEY]:
+        assert isinstance(msg_type.value, str)
+        Message(
+            id="test",
+            type=msg_type,
+            title="Test",
+            content="Test",
+            author="Test",
+            date=datetime(2024, 9, 1, 8, 0),
+            read=False,
+        )
+
+
+def test_agenda_change_type_enum_values() -> None:
+    """Vérifie que les valeurs de l'enum AgendaChangeType sont correctes.
+
+    :raises ValidationError: Si une valeur invalide est utilisée.
+    """
+    # Test des valeurs valides
+    for change_type in [
+        AgendaChangeType.ADDED,
+        AgendaChangeType.REMOVED,
+        AgendaChangeType.MODIFIED,
+    ]:
+        assert isinstance(change_type.value, str)
+        if change_type == AgendaChangeType.ADDED:
+            AgendaChange(
+                type=change_type,
+                lesson=Lesson(
+                    id="test",
+                    start=datetime(2024, 9, 6, 8, 0),
+                    end=datetime(2024, 9, 6, 9, 0),
+                    subject="Test",
+                    group=None,
+                    content=None,
+                ),
+                theoretical_lesson=None,
+            )
+        elif change_type == AgendaChangeType.REMOVED:
+            AgendaChange(
+                type=change_type,
+                lesson=None,
+                theoretical_lesson=TheoreticalLesson(
+                    id="test",
+                    day_of_week=0,
+                    start_time=time(8, 0, 0),
+                    end_time=time(9, 0, 0),
+                    subject="Test",
+                ),
+            )
+        else:
+            AgendaChange(
+                type=change_type,
+                lesson=Lesson(
+                    id="test",
+                    start=datetime(2024, 9, 6, 8, 0),
+                    end=datetime(2024, 9, 6, 9, 0),
+                    subject="Test",
+                    group=None,
+                    content=None,
+                ),
+                theoretical_lesson=None,
+            )

tests/unit/test_models_immutability.py

@@ -0,0 +1,409 @@
+"""Tests d'immuabilité des modèles Pydantic figés.
+
+Ce module vérifie que les modèles marqués comme figés (frozen=True) ne peuvent pas
+être modifiés après construction, et que leurs collections sont bien des tuples.
+"""
+
+from __future__ import annotations
+
+from datetime import date, datetime
+from typing import Any
+
+import pytest
+from pydantic import BaseModel, ValidationError
+
+from pronote_sync.models.agenda import HomeworkBlock, Lesson, LessonStatus
+from pronote_sync.models.blog import BlogArticle, ExternalInfo
+from pronote_sync.models.diff import AgendaChange, AgendaChangeType
+from pronote_sync.models.homework import Homework
+from pronote_sync.models.message import Message, MessageType
+from pronote_sync.models.pronote import PronoteData
+from pronote_sync.models.sync import CalDAVSyncResult, CalDAVSyncStatus
+from pronote_sync.models.xmpp import XmppMessage
+
+
+@pytest.mark.parametrize(
+    "model_class, kwargs",
+    [
+        (
+            Lesson,
+            {
+                "id": "lesson-immutability",
+                "start": datetime(2024, 9, 6, 8, 0, 0),
+                "end": datetime(2024, 9, 6, 9, 30, 0),
+                "subject": "Mathématiques",
+                "teachers": ("M. Dupont", "Mme Martin"),
+                "rooms": ("Salle 101",),
+                "status": LessonStatus.NORMAL,
+            },
+        ),
+        (
+            Homework,
+            {
+                "id": "hw-immutability",
+                "subject": "Physique",
+                "teachers": ("M. Martin",),
+                "due_on": date(2024, 9, 15),
+                "text": "Exercice à rendre",
+            },
+        ),
+        (
+            AgendaChange,
+            {
+                "type": AgendaChangeType.ADDED,
+                "lesson": Lesson(
+                    id="lesson-ref",
+                    start=datetime(2024, 9, 6, 10, 0, 0),
+                    end=datetime(2024, 9, 6, 11, 30, 0),
+                    subject="Histoire",
+                    teachers=("Mme Bernard",),
+                    rooms=("Salle 201",),
+                    group=None,
+                    content=None,
+                ),
+            },
+        ),
+        (
+            XmppMessage,
+            {
+                "target_date": date(2024, 9, 6),
+                "synthesis": "Test immuabilité",
+            },
+        ),
+        (
+            HomeworkBlock,
+            {
+                "kind": "due",
+                "date": date(2024, 9, 15),
+                "text": "Devoir à faire",
+            },
+        ),
+        (
+            ExternalInfo,
+            {
+                "blog_articles": (
+                    BlogArticle(
+                        id="article-1",
+                        title="Article 1",
+                        url="https://example.com/1",
+                        published_at=datetime(2024, 9, 1, 8, 0, 0),
+                        updated_at=None,
+                        category=None,
+                        author=None,
+                        content_html="<p>Contenu</p>",
+                        content_text="Contenu",
+                    ),
+                ),
+                "pronote_messages": (
+                    Message(
+                        id="msg-1",
+                        type=MessageType.INFORMATION,
+                        title="Message 1",
+                        content="Message",
+                        author="Auteur",
+                        date=datetime(2024, 9, 1, 8, 0, 0),
+                        read=False,
+                    ),
+                ),
+            },
+        ),
+    ],
+)
+def test_frozen_model_rejects_field_assignment(
+    model_class: type[BaseModel], kwargs: dict[str, Any]
+) -> None:
+    """Vérifie qu'un modèle figé rejette toute tentative d'assignation de champ.
+
+    :param model_class: Classe du modèle figé.
+    :type model_class: type[BaseModel]
+    :param kwargs: Arguments de constructeur valides.
+    :type kwargs: dict[str, Any]
+    """
+    instance: Any = model_class(**kwargs)
+
+    # Tentative d'assignation directe sur un champ
+    with pytest.raises(ValidationError) as exc_info:
+        if model_class == Lesson:
+            instance.subject = "Nouveau sujet"
+        elif model_class == Homework:
+            instance.subject = "Nouveau sujet"
+        elif model_class == AgendaChange:
+            instance.details = "Nouveaux détails"
+        elif model_class == XmppMessage:
+            instance.synthesis = "Nouvelle synthèse"
+        elif model_class == HomeworkBlock:
+            instance.text = "Nouveau texte"
+        elif model_class == ExternalInfo:
+            instance.other_info = ("Nouvelle info",)
+
+    error_msg = str(exc_info.value).lower()
+    assert "instance is frozen" in error_msg or "immutable" in error_msg
+
+
+@pytest.mark.parametrize(
+    "model_class, kwargs, field_name, expected_type",
+    [
+        (
+            Lesson,
+            {
+                "id": "lesson-tuple",
+                "start": datetime(2024, 9, 6, 8, 0),
+                "end": datetime(2024, 9, 6, 9, 0),
+                "subject": "Test",
+            },
+            "teachers",
+            tuple,
+        ),
+        (
+            Lesson,
+            {
+                "id": "lesson-tuple2",
+                "start": datetime(2024, 9, 6, 8, 0),
+                "end": datetime(2024, 9, 6, 9, 0),
+                "subject": "Test",
+            },
+            "rooms",
+            tuple,
+        ),
+        (
+            Lesson,
+            {
+                "id": "lesson-tuple3",
+                "start": datetime(2024, 9, 6, 8, 0),
+                "end": datetime(2024, 9, 6, 9, 0),
+                "subject": "Test",
+                "homework_blocks": (),
+            },
+            "homework_blocks",
+            tuple,
+        ),
+        (
+            Homework,
+            {
+                "id": "hw-tuple",
+                "subject": "Test",
+                "teachers": ("Prof 1",),
+                "due_on": date(2024, 9, 15),
+                "text": "Devoir",
+            },
+            "teachers",
+            tuple,
+        ),
+        (
+            AgendaChange,
+            {
+                "type": AgendaChangeType.ADDED,
+                "lesson": Lesson(
+                    id="ref",
+                    start=datetime(2024, 9, 6, 8, 0),
+                    end=datetime(2024, 9, 6, 9, 0),
+                    subject="Test",
+                    group=None,
+                    content=None,
+                ),
+            },
+            "details",
+            str,
+        ),
+        (XmppMessage, {"target_date": date(2024, 9, 6)}, "homeworks", tuple),
+        (XmppMessage, {"target_date": date(2024, 9, 6)}, "changes", tuple),
+        (XmppMessage, {"target_date": date(2024, 9, 6)}, "messages", tuple),
+        (
+            ExternalInfo,
+            {"blog_articles": (), "pronote_messages": (), "other_info": ()},
+            "blog_articles",
+            tuple,
+        ),
+        (
+            ExternalInfo,
+            {"blog_articles": (), "pronote_messages": (), "other_info": ()},
+            "pronote_messages",
+            tuple,
+        ),
+        (
+            ExternalInfo,
+            {"blog_articles": (), "pronote_messages": (), "other_info": ()},
+            "other_info",
+            tuple,
+        ),
+    ],
+)
+def test_collection_fields_are_tuples(
+    model_class: type[BaseModel],
+    kwargs: dict[str, Any],
+    field_name: str,
+    expected_type: type[Any],
+) -> None:
+    """Vérifie que les champs de collection sont bien des tuples et non des listes.
+
+    :param model_class: Classe du modèle.
+    :type model_class: type[BaseModel]
+    :param kwargs: Arguments de constructeur valides.
+    :type kwargs: dict[str, Any]
+    :param field_name: Nom du champ de collection à vérifier.
+    :type field_name: str
+    :param expected_type: Type attendu (tuple).
+    :type expected_type: type
+    """
+    instance = model_class(**kwargs)
+    field_value = getattr(instance, field_name)
+    assert isinstance(field_value, expected_type), (
+        f"Le champ {field_name} devrait être de type {expected_type.__name__}, "
+        f"got {type(field_value).__name__}"
+    )
+
+
+@pytest.mark.parametrize(
+    "model_class, kwargs, field_name",
+    [
+        (
+            Lesson,
+            {
+                "id": "lesson-no-append",
+                "start": datetime(2024, 9, 6, 8, 0),
+                "end": datetime(2024, 9, 6, 9, 0),
+                "subject": "Test",
+            },
+            "teachers",
+        ),
+        (
+            Lesson,
+            {
+                "id": "lesson-no-append2",
+                "start": datetime(2024, 9, 6, 8, 0),
+                "end": datetime(2024, 9, 6, 9, 0),
+                "subject": "Test",
+            },
+            "rooms",
+        ),
+        (
+            Homework,
+            {
+                "id": "hw-no-append",
+                "subject": "Test",
+                "teachers": ("Prof 1",),
+                "due_on": date(2024, 9, 15),
+                "text": "Devoir",
+            },
+            "teachers",
+        ),
+        (
+            ExternalInfo,
+            {"blog_articles": (), "pronote_messages": (), "other_info": ()},
+            "blog_articles",
+        ),
+        (
+            ExternalInfo,
+            {"blog_articles": (), "pronote_messages": (), "other_info": ()},
+            "pronote_messages",
+        ),
+        (
+            ExternalInfo,
+            {"blog_articles": (), "pronote_messages": (), "other_info": ()},
+            "other_info",
+        ),
+    ],
+)
+def test_collection_fields_reject_append(
+    model_class: type[BaseModel], kwargs: dict[str, Any], field_name: str
+) -> None:
+    """Vérifie que les champs de collection (tuples) rejettent la méthode append.
+
+    :param model_class: Classe du modèle.
+    :type model_class: type[BaseModel]
+    :param kwargs: Arguments de constructeur valides.
+    :type kwargs: dict[str, Any]
+    :param field_name: Nom du champ de collection.
+    :type field_name: str
+    """
+    instance = model_class(**kwargs)
+
+    with pytest.raises(AttributeError) as exc_info:
+        collection = getattr(instance, field_name)
+        collection.append("new_item")
+
+    assert "'tuple' object has no attribute 'append'" in str(exc_info.value)
+
+
+@pytest.mark.parametrize(
+    "model_class, kwargs, field_name, new_value",
+    [
+        (CalDAVSyncResult, {"status": CalDAVSyncStatus.SUCCESS}, "added", 5),
+        (CalDAVSyncResult, {"status": CalDAVSyncStatus.SUCCESS}, "updated", 3),
+        (CalDAVSyncResult, {"status": CalDAVSyncStatus.SUCCESS}, "removed", 2),
+        (
+            CalDAVSyncResult,
+            {"status": CalDAVSyncStatus.FAILED},
+            "errors",
+            ["Erreur 1", "Erreur 2"],
+        ),
+    ],
+)
+def test_mutable_models_accept_field_assignment(
+    model_class: type[BaseModel],
+    kwargs: dict[str, Any],
+    field_name: str,
+    new_value: Any,
+) -> None:
+    """Vérifie que les modèles mutables (non figés) acceptent l'assignation de champs.
+
+    :param model_class: Classe du modèle mutable.
+    :type model_class: type[BaseModel]
+    :param kwargs: Arguments de constructeur valides.
+    :type kwargs: dict[str, Any]
+    :param field_name: Nom du champ à assigner.
+    :type field_name: str
+    :param new_value: Nouvelle valeur à assigner.
+    :type new_value: Any
+    """
+    instance = model_class(**kwargs)
+
+    # Assignation du champ
+    setattr(instance, field_name, new_value)
+
+    # Vérification que la valeur a bien été assignée
+    assert getattr(instance, field_name) == new_value, (
+        f"Le champ {field_name} n'a pas été correctement assigné"
+    )
+
+
+@pytest.mark.parametrize(
+    "model_class, kwargs",
+    [
+        (
+            PronoteData,
+            {
+                "target_date": date(2024, 9, 6),
+                "generated_at": datetime(2024, 9, 6, 8, 0, 0),
+            },
+        ),
+        (CalDAVSyncResult, {"status": CalDAVSyncStatus.SUCCESS}),
+    ],
+)
+def test_mutable_models_reject_frozen_assignment(
+    model_class: type[BaseModel], kwargs: dict[str, Any]
+) -> None:
+    """Vérifie que les modèles mutables peuvent être modifiés mais pas rendus figés.
+
+    Note: Les modèles mutables comme PronoteData et CalDAVSyncResult n'ont pas
+    ConfigDict(frozen=True), donc ils peuvent être modifiés.
+
+    :param model_class: Classe du modèle mutable.
+    :type model_class: type[BaseModel]
+    :param kwargs: Arguments de constructeur valides.
+    :type kwargs: dict[str, Any]
+    """
+    from pronote_sync.models.pronote import PronoteData
+
+    instance: Any = model_class(**kwargs)
+
+    # Assignation normale doit fonctionner
+    if model_class == PronoteData:
+        instance.lessons.append("dummy")
+    else:
+        instance.added = 10
+
+    # Vérification que l'instance n'est pas figée
+    assert not hasattr(instance.model_config, "frozen") or not instance.model_config.get(
+        "frozen", False
+    )

tests/unit/test_models_invariants.py

@@ -0,0 +1,287 @@
+"""Tests d'invariants et de validation des modèles Pydantic.
+
+Ce module vérifie que les validateurs de modèle rejettent les données invalides
+conformément aux spécifications (ex: ordre des dates, plages de valeurs).
+"""
+
+from __future__ import annotations
+
+from datetime import date, datetime, time
+
+import pytest
+from pydantic import ValidationError
+
+from pronote_sync.models.agenda import (
+    Lesson,
+    SchoolEvent,
+    SchoolEventKind,
+    TheoreticalLesson,
+)
+from pronote_sync.models.diff import AgendaChange, AgendaChangeType
+from pronote_sync.models.sync import CalDAVSyncResult, CalDAVSyncStatus
+
+
+class TestTheoreticalLessonDayOfWeek:
+    """Tests de validation du champ day_of_week pour TheoreticalLesson."""
+
+    def test_day_of_week_7_invalid(self) -> None:
+        """Vérifie que day_of_week=7 lève une ValidationError."""
+        with pytest.raises(ValidationError):
+            TheoreticalLesson(
+                id="test",
+                day_of_week=7,
+                start_time=time(8, 0, 0),
+                end_time=time(9, 30, 0),
+                subject="Mathématiques",
+            )
+
+    def test_day_of_week_minus_1_invalid(self) -> None:
+        """Vérifie que day_of_week=-1 lève une ValidationError."""
+        with pytest.raises(ValidationError) as exc_info:
+            TheoreticalLesson(
+                id="test",
+                day_of_week=-1,
+                start_time=time(8, 0, 0),
+                end_time=time(9, 30, 0),
+                subject="Mathématiques",
+            )
+        assert any(
+            "greater than or equal to 0" in str(error).lower() or "le 6" in str(error).lower()
+            for error in exc_info.value.errors()
+        )
+
+    def test_day_of_week_0_valid(self) -> None:
+        """Vérifie que day_of_week=0 (lundi) est valide."""
+        instance = TheoreticalLesson(
+            id="test",
+            day_of_week=0,
+            start_time=time(8, 0, 0),
+            end_time=time(9, 30, 0),
+            subject="Mathématiques",
+        )
+        assert instance.day_of_week == 0
+
+    def test_day_of_week_6_valid(self) -> None:
+        """Vérifie que day_of_week=6 (dimanche) est valide."""
+        instance = TheoreticalLesson(
+            id="test",
+            day_of_week=6,
+            start_time=time(8, 0, 0),
+            end_time=time(9, 30, 0),
+            subject="Mathématiques",
+        )
+        assert instance.day_of_week == 6
+
+
+class TestLessonTimeOrder:
+    """Tests de validation de l'ordre temporel pour Lesson."""
+
+    def test_lesson_end_before_start_invalid(self) -> None:
+        """Vérifie que end <= start lève une ValidationError."""
+        with pytest.raises(ValidationError) as exc_info:
+            Lesson(
+                id="test",
+                start=datetime(2024, 9, 6, 10, 0, 0),
+                end=datetime(2024, 9, 6, 9, 0, 0),  # end avant start
+                subject="Mathématiques",
+                group=None,
+                content=None,
+            )
+        assert any(
+            "end doit être postérieur à start" in str(error) for error in exc_info.value.errors()
+        )
+
+    def test_lesson_end_after_start_valid(self) -> None:
+        """Vérifie que end > start est valide."""
+        instance = Lesson(
+            id="test",
+            start=datetime(2024, 9, 6, 8, 0, 0),
+            end=datetime(2024, 9, 6, 9, 30, 0),
+            subject="Mathématiques",
+            group=None,
+            content=None,
+        )
+        assert instance.end > instance.start
+
+
+class TestTheoreticalLessonTimeOrder:
+    """Tests de validation de l'ordre temporel pour TheoreticalLesson."""
+
+    def test_theoretical_lesson_end_time_before_start_time_invalid(self) -> None:
+        """Vérifie que end_time <= start_time lève une ValidationError."""
+        with pytest.raises(ValidationError) as exc_info:
+            TheoreticalLesson(
+                id="test",
+                day_of_week=0,
+                start_time=time(9, 0, 0),
+                end_time=time(8, 0, 0),  # end_time avant start_time
+                subject="Mathématiques",
+            )
+        assert any(
+            "end_time doit être postérieur à start_time" in str(error)
+            for error in exc_info.value.errors()
+        )
+
+    def test_theoretical_lesson_end_time_after_start_time_valid(self) -> None:
+        """Vérifie que end_time > start_time est valide."""
+        instance = TheoreticalLesson(
+            id="test",
+            day_of_week=0,
+            start_time=time(8, 0, 0),
+            end_time=time(9, 30, 0),
+            subject="Mathématiques",
+        )
+        assert instance.end_time > instance.start_time
+
+
+class TestSchoolEventDateOrder:
+    """Tests de validation de l'ordre des dates pour SchoolEvent."""
+
+    def test_school_event_to_date_before_from_date_invalid(self) -> None:
+        """Vérifie que to_date < from_date lève une ValidationError."""
+        with pytest.raises(ValidationError) as exc_info:
+            SchoolEvent(
+                kind=SchoolEventKind.HOLIDAY,
+                label="Test",
+                from_date=date(2024, 10, 20),
+                to_date=date(2024, 10, 19),  # to_date avant from_date
+            )
+        assert any(
+            "to_date doit être postérieur ou égal à from_date" in str(error)
+            for error in exc_info.value.errors()
+        )
+
+    def test_school_event_to_date_equal_from_date_valid(self) -> None:
+        """Vérifie que to_date == from_date est valide."""
+        instance = SchoolEvent(
+            kind=SchoolEventKind.HOLIDAY,
+            label="Test",
+            from_date=date(2024, 10, 20),
+            to_date=date(2024, 10, 20),  # égal
+        )
+        assert instance.to_date >= instance.from_date
+
+    def test_school_event_to_date_after_from_date_valid(self) -> None:
+        """Vérifie que to_date > from_date est valide."""
+        instance = SchoolEvent(
+            kind=SchoolEventKind.HOLIDAY,
+            label="Test",
+            from_date=date(2024, 10, 20),
+            to_date=date(2024, 10, 25),
+        )
+        assert instance.to_date >= instance.from_date
+
+
+class TestAgendaChangeConsistency:
+    """Tests de cohérence des changements d'agenda."""
+
+    def test_agenda_change_added_without_lesson_invalid(self) -> None:
+        """Vérifie que type=ADDED avec lesson=None lève une ValidationError."""
+        with pytest.raises(ValidationError) as exc_info:
+            AgendaChange(type=AgendaChangeType.ADDED, lesson=None, theoretical_lesson=None)
+        assert any(
+            "lesson est requis pour le type" in str(error) for error in exc_info.value.errors()
+        )
+
+    def test_agenda_change_removed_without_theoretical_lesson_invalid(self) -> None:
+        """Vérifie que type=REMOVED avec theoretical_lesson=None lève une ValidationError."""
+        with pytest.raises(ValidationError) as exc_info:
+            AgendaChange(
+                type=AgendaChangeType.REMOVED,
+                lesson=None,
+                theoretical_lesson=None,
+            )
+        assert any(
+            "theoretical_lesson est requis pour le type" in str(error)
+            for error in exc_info.value.errors()
+        )
+
+    def test_agenda_change_modified_without_lesson_invalid(self) -> None:
+        """Vérifie que type=MODIFIED avec lesson=None lève une ValidationError."""
+        with pytest.raises(ValidationError) as exc_info:
+            AgendaChange(type=AgendaChangeType.MODIFIED, lesson=None, theoretical_lesson=None)
+        assert any(
+            "lesson est requis pour le type" in str(error) for error in exc_info.value.errors()
+        )
+
+    def test_agenda_change_added_with_lesson_valid(self) -> None:
+        """Vérifie que type=ADDED avec lesson=<valide> est valide."""
+        lesson = Lesson(
+            id="lesson-valid",
+            start=datetime(2024, 9, 6, 8, 0, 0),
+            end=datetime(2024, 9, 6, 9, 30, 0),
+            subject="Mathématiques",
+            group=None,
+            content=None,
+        )
+        instance = AgendaChange(
+            type=AgendaChangeType.ADDED,
+            lesson=lesson,
+            theoretical_lesson=None,
+        )
+        assert instance.type == AgendaChangeType.ADDED
+        assert instance.lesson is not None
+
+    def test_agenda_change_removed_with_theoretical_lesson_valid(self) -> None:
+        """Vérifie que type=REMOVED avec theoretical_lesson=<valide> est valide."""
+        theoretical_lesson = TheoreticalLesson(
+            id="theo-lesson-valid",
+            day_of_week=0,
+            start_time=time(8, 0, 0),
+            end_time=time(9, 30, 0),
+            subject="Mathématiques",
+        )
+        instance = AgendaChange(
+            type=AgendaChangeType.REMOVED,
+            lesson=None,
+            theoretical_lesson=theoretical_lesson,
+        )
+        assert instance.type == AgendaChangeType.REMOVED
+        assert instance.theoretical_lesson is not None
+
+    def test_agenda_change_modified_with_lesson_valid(self) -> None:
+        """Vérifie que type=MODIFIED avec lesson=<valide> est valide."""
+        lesson = Lesson(
+            id="lesson-valid-mod",
+            start=datetime(2024, 9, 6, 10, 0, 0),
+            end=datetime(2024, 9, 6, 11, 30, 0),
+            subject="Physique",
+            group=None,
+            content=None,
+        )
+        instance = AgendaChange(
+            type=AgendaChangeType.MODIFIED,
+            lesson=lesson,
+            theoretical_lesson=None,
+        )
+        assert instance.type == AgendaChangeType.MODIFIED
+        assert instance.lesson is not None
+
+
+class TestCalDAVSyncResultInvariants:
+    """Tests de validation des champs numériques de CalDAVSyncResult."""
+
+    def test_caldav_sync_result_added_negative_invalid(self) -> None:
+        """Vérifie que added=-1 lève une ValidationError."""
+        with pytest.raises(ValidationError) as exc_info:
+            CalDAVSyncResult(status=CalDAVSyncStatus.SUCCESS, added=-1, updated=0, removed=0)
+        assert any("greater than or equal to 0" in str(error) for error in exc_info.value.errors())
+
+    def test_caldav_sync_result_updated_negative_invalid(self) -> None:
+        """Vérifie que updated=-1 lève une ValidationError."""
+        with pytest.raises(ValidationError) as exc_info:
+            CalDAVSyncResult(status=CalDAVSyncStatus.SUCCESS, added=0, updated=-1, removed=0)
+        assert any("greater than or equal to 0" in str(error) for error in exc_info.value.errors())
+
+    def test_caldav_sync_result_removed_negative_invalid(self) -> None:
+        """Vérifie que removed=-1 lève une ValidationError."""
+        with pytest.raises(ValidationError) as exc_info:
+            CalDAVSyncResult(status=CalDAVSyncStatus.SUCCESS, added=0, updated=0, removed=-1)
+        assert any("greater than or equal to 0" in str(error) for error in exc_info.value.errors())
+
+    def test_caldav_sync_result_zero_values_valid(self) -> None:
+        """Vérifie que les valeurs à zéro sont valides."""
+        instance = CalDAVSyncResult(status=CalDAVSyncStatus.SUCCESS, added=0, updated=0, removed=0)
+        assert instance.added == 0
+        assert instance.updated == 0
+        assert instance.removed == 0