fix: prevent source state writes in dry-run

tests/unit/test_blog_state.py

@@ -35,6 +35,49 @@ def test_state_file_absent_empty_state(tmp_path: Path) -> None:
     assert state.get_cache_headers() == (None, None)
 
 
+def test_disabled_persistence_keeps_updates_in_memory_without_creating_file(tmp_path: Path) -> None:
+    """Vérifie que la persistance désactivée conserve l'état uniquement en mémoire.
+
+    :param tmp_path: Fixture pytest pour un répertoire temporaire.
+    :return: None
+    """
+    state_file = tmp_path / "state.json"
+    state = BlogRSSState(state_file, persistence_enabled=False)
+
+    state.add_guids(["guid-1"])
+    state.update_cache_headers("etag-123", "Wed, 01 Sep 2026 GMT")
+
+    assert state.get_known_guids() == frozenset({"guid-1"})
+    assert state.get_cache_headers() == ("etag-123", "Wed, 01 Sep 2026 GMT")
+    assert not state_file.exists()
+
+
+def test_disabled_persistence_preserves_existing_file(tmp_path: Path) -> None:
+    """Vérifie que la persistance désactivée ne modifie pas l'état déjà stocké.
+
+    :param tmp_path: Fixture pytest pour un répertoire temporaire.
+    :return: None
+    """
+    state_file = tmp_path / "state.json"
+    original_content = json.dumps(
+        {
+            "version": 1,
+            "known_guids": ["existing-guid"],
+            "etag": "old-etag",
+            "last_modified": "Tue, 31 Aug 2026 GMT",
+        }
+    )
+    state_file.write_text(original_content, encoding="utf-8")
+    state = BlogRSSState(state_file, persistence_enabled=False)
+
+    state.add_guids(["new-guid"])
+    state.update_cache_headers("new-etag", "Wed, 01 Sep 2026 GMT")
+
+    assert state.get_known_guids() == frozenset({"existing-guid", "new-guid"})
+    assert state.get_cache_headers() == ("new-etag", "Wed, 01 Sep 2026 GMT")
+    assert state_file.read_text(encoding="utf-8") == original_content
+
+
 def test_add_guids_persists(tmp_path: Path) -> None:
     """Vérifie que l'ajout de GUID persiste dans le fichier JSON.