fix: unicode in models

libs/core/kiln_ai/datamodel/basemodel.py

@@ -139,7 +139,7 @@ def load_from_file(cls: Type[T], path: Path | str, readonly: bool = False) -> T:
         cached_model = ModelCache.shared().get_model(path, cls, readonly=readonly)
         if cached_model is not None:
             return cached_model
-        with open(path, "r") as file:
+        with open(path, "r", encoding="utf-8") as file:
             # modified time of file for cache invalidation. From file descriptor so it's atomic w read.
             mtime_ns = os.fstat(file.fileno()).st_mtime_ns
             file_data = file.read()
@@ -198,7 +198,7 @@ def save_to_file(self) -> None:
             )
         path.parent.mkdir(parents=True, exist_ok=True)
         json_data = self.model_dump_json(indent=2, exclude={"path"})
-        with open(path, "w") as file:
+        with open(path, "w", encoding="utf-8") as file:
             file.write(json_data)
         # save the path so even if something like name changes, the file doesn't move
         self.path = path

libs/core/kiln_ai/datamodel/test_models.py

@@ -71,6 +71,20 @@ def test_save_to_file(test_project_file):
     assert data["description"] == "Test Description"
 
 
+def test_save_to_file_non_ascii(test_project_file):
+    project = Project(
+        name="Test Project", description="Chúc mừng!", path=test_project_file
+    )
+    project.save_to_file()
+
+    with open(test_project_file, "r", encoding="utf-8") as file:
+        data = json.load(file)
+
+    assert data["v"] == 1
+    assert data["name"] == "Test Project"
+    assert data["description"] == "Chúc mừng!"
+
+
 def test_task_defaults():
     task = Task(name="Test Task", instruction="Test Instruction")
     assert task.description is None