Fix: Inference of python model names from the file system (#3844)

sqlmesh/core/model/decorator.py

@@ -20,7 +20,7 @@
     render_meta_fields,
 )
 from sqlmesh.core.model.kind import ModelKindName, _ModelKind
-from sqlmesh.utils import registry_decorator
+from sqlmesh.utils import registry_decorator, DECORATOR_RETURN_TYPE
 from sqlmesh.utils.errors import ConfigError
 from sqlmesh.utils.metaprogramming import build_env, serialize_env
 
@@ -39,6 +39,7 @@ def __init__(self, name: t.Optional[str] = None, is_sql: bool = False, **kwargs:
         if not is_sql and "columns" not in kwargs:
             raise ConfigError("Python model must define column schema.")
 
+        self.name_provided = bool(name)
         self.name = name or ""
         self.is_sql = is_sql
         self.kwargs = kwargs
@@ -76,6 +77,13 @@ def __init__(self, name: t.Optional[str] = None, is_sql: bool = False, **kwargs:
             for column_name, column_type in self.kwargs.pop("columns", {}).items()
         }
 
+    def __call__(
+        self, func: t.Callable[..., DECORATOR_RETURN_TYPE]
+    ) -> t.Callable[..., DECORATOR_RETURN_TYPE]:
+        if not self.name_provided:
+            self.name = get_model_name(Path(inspect.getfile(func)))
+        return super().__call__(func)
+
     def model(
         self,
         *,
@@ -97,10 +105,7 @@ def model(
         env: t.Dict[str, t.Any] = {}
         entrypoint = self.func.__name__
 
-        if not self.name and infer_names:
-            self.name = get_model_name(Path(inspect.getfile(self.func)))
-
-        if not self.name:
+        if not self.name_provided and not infer_names:
             raise ConfigError("Python model must have a name.")
 
         kind = self.kwargs.get("kind", None)

tests/core/test_model.py

@@ -6024,6 +6024,32 @@ def my_model(context, **kwargs):
     assert isinstance(context.get_model(expected_name), PythonModel)
 
 
+def test_python_model_name_inference_multiple_models(tmp_path: Path) -> None:
+    init_example_project(tmp_path, dialect="duckdb")
+    config = Config(
+        model_defaults=ModelDefaultsConfig(dialect="duckdb"),
+        model_naming=NameInferenceConfig(infer_names=True),
+    )
+
+    path_a = tmp_path / "models/test_schema/test_model_a.py"
+    path_b = tmp_path / "models/test_schema/test_model_b.py"
+
+    model_payload = """from sqlmesh import model
+@model(
+    columns={'"COL"': "int"},
+)
+def my_model(context, **kwargs):
+    pass"""
+
+    path_a.parent.mkdir(parents=True, exist_ok=True)
+    path_a.write_text(model_payload)
+    path_b.write_text(model_payload)
+
+    context = Context(paths=tmp_path, config=config)
+    assert context.get_model("test_schema.test_model_a").name == "test_schema.test_model_a"
+    assert context.get_model("test_schema.test_model_b").name == "test_schema.test_model_b"
+
+
 def test_custom_kind():
     from sqlmesh import CustomMaterialization