make ignore_missing_model_attributes behaviour optional (#66)

make "ignore_missing_model_attributes" behaviour opt-in

Author: mkurnikov

README.md

@@ -44,6 +44,9 @@ django_settings = mysettings.local
 # if True, all unknown settings in django.conf.settings will fallback to Any,
 # specify it if your settings are loaded dynamically to avoid false positives
 ignore_missing_settings = True
+
+# if True, unknown attributes on Model instances won't produce errors
+ignore_missing_model_attributes = True
 ```
 
 ## To get help

mypy_django_plugin/config.py

@@ -8,6 +8,7 @@
 class Config:
     django_settings_module: Optional[str] = None
     ignore_missing_settings: bool = False
+    ignore_missing_model_attributes: bool = False
 
     @classmethod
     def from_config_file(cls, fpath: str) -> 'Config':
@@ -22,5 +23,9 @@ def from_config_file(cls, fpath: str) -> 'Config':
             django_settings = django_settings.strip()
 
         return Config(django_settings_module=django_settings,
-                      ignore_missing_settings=bool(ini_config.get('mypy_django_plugin', 'ignore_missing_settings',
-                                                                  fallback=False)))
+                      ignore_missing_settings=bool(ini_config.get('mypy_django_plugin',
+                                                                  'ignore_missing_settings',
+                                                                  fallback=False)),
+                      ignore_missing_model_attributes=bool(ini_config.get('mypy_django_plugin',
+                                                                          'ignore_missing_model_attributes',
+                                                                          fallback=False)))

mypy_django_plugin/main.py

@@ -31,7 +31,7 @@
 )
 
 
-def transform_model_class(ctx: ClassDefContext) -> None:
+def transform_model_class(ctx: ClassDefContext, ignore_missing_model_attributes: bool) -> None:
     try:
         sym = ctx.api.lookup_fully_qualified(helpers.MODEL_CLASS_FULLNAME)
     except KeyError:
@@ -41,7 +41,7 @@ def transform_model_class(ctx: ClassDefContext) -> None:
         if sym is not None and isinstance(sym.node, TypeInfo):
             helpers.get_django_metadata(sym.node)['model_bases'][ctx.cls.fullname] = 1
 
-    process_model_class(ctx)
+    process_model_class(ctx, ignore_missing_model_attributes)
 
 
 def transform_manager_class(ctx: ClassDefContext) -> None:
@@ -248,7 +248,8 @@ def get_method_hook(self, fullname: str
     def get_base_class_hook(self, fullname: str
                             ) -> Optional[Callable[[ClassDefContext], None]]:
         if fullname in self._get_current_model_bases():
-            return transform_model_class
+            return partial(transform_model_class,
+                           ignore_missing_model_attributes=self.config.ignore_missing_model_attributes)
 
         if fullname in self._get_current_manager_bases():
             return transform_manager_class

mypy_django_plugin/transformers/models.py

@@ -286,7 +286,7 @@ def add_get_set_attr_fallback_to_any(ctx: ClassDefContext):
     add_method(ctx, '__setattr__', [name_arg, value_arg], any)
 
 
-def process_model_class(ctx: ClassDefContext) -> None:
+def process_model_class(ctx: ClassDefContext, ignore_unknown_attributes: bool) -> None:
     initializers = [
         InjectAnyAsBaseForNestedMeta,
         AddDefaultObjectsManager,
@@ -299,5 +299,5 @@ def process_model_class(ctx: ClassDefContext) -> None:
 
     add_dummy_init_method(ctx)
 
-    # allow unspecified attributes for now
-    add_get_set_attr_fallback_to_any(ctx)
+    if ignore_unknown_attributes:
+        add_get_set_attr_fallback_to_any(ctx)

test-data/typecheck/fields.test

@@ -75,7 +75,7 @@ reveal_type(User().my_pk)  # E: Revealed type is 'builtins.int*'
 reveal_type(User().id)
 [out]
 main:7: error: Revealed type is 'Any'
-main:7: error: Default primary key 'id' is not defined
+main:7: error: "User" has no attribute "id"
 [/CASE]
 
 [CASE test_meta_nested_class_allows_subclassing_in_multiple_inheritance]

test-data/typecheck/model.test

@@ -1,28 +1,60 @@
-[CASE test_model_subtype_relationship_and_getting_and_setting_attributes]
+[CASE test_typechecking_for_model_subclasses]
 from django.db import models
 
 class A(models.Model):
     pass
-
 class B(models.Model):
     b_attr = 1
     pass
-
 class C(A):
     pass
 
 def service(a: A) -> int:
     pass
 
+b_instance = B()
+service(b_instance)  # E: Argument 1 to "service" has incompatible type "B"; expected "A"
+
 a_instance = A()
+c_instance = C()
+service(a_instance)
+service(c_instance)
+[/CASE]
+
+
+[CASE fail_if_no_such_attribute_on_model]
+from django.db import models
+
+class B(models.Model):
+    b_attr = 1
+    pass
+
 b_instance = B()
 reveal_type(b_instance.b_attr) # E: Revealed type is 'builtins.int'
 
+reveal_type(b_instance.non_existent_attribute)
+b_instance.non_existent_attribute = 2
+[out]
+main:10: error: Revealed type is 'Any'
+main:10: error: "B" has no attribute "non_existent_attribute"
+main:11: error: "B" has no attribute "non_existent_attribute"
+[/CASE]
+
 
+[CASE ignore_missing_attributes_if_setting_is_passed]
+from django.db import models
+
+class B(models.Model):
+    pass
+
+b_instance = B()
 reveal_type(b_instance.non_existent_attribute) # E: Revealed type is 'Any'
 b_instance.non_existent_attribute = 2
 
-service(b_instance)  # E: Argument 1 to "service" has incompatible type "B"; expected "A"
+[env MYPY_DJANGO_CONFIG=${MYPY_CWD}/mypy_django.ini]
 
-c_instance = C()
-service(c_instance)
+[file mypy_django.ini]
+[[mypy_django_plugin]
+ignore_missing_model_attributes = True
+
+[/CASE]

test-data/typecheck/related_fields.test

@@ -109,8 +109,10 @@ class View(models.Model):
     app = models.ForeignKey(to=App, related_name='views', on_delete=models.CASCADE)
 
 reveal_type(View().app.views)  # E: Revealed type is 'django.db.models.manager.RelatedManager[main.View]'
-reveal_type(View().app.unknown)  # E: Revealed type is 'Any'
+reveal_type(View().app.unknown)
 [out]
+main:7: error: Revealed type is 'Any'
+main:7: error: "App" has no attribute "unknown"
 
 [file myapp/__init__.py]
 [file myapp/models.py]
@@ -307,6 +309,10 @@ book = Book()
 reveal_type(book.publisher)  # E: Revealed type is 'main.Publisher*'
 
 publisher = Publisher()
-reveal_type(publisher.books)  # E: Revealed type is 'Any'
+reveal_type(publisher.books)
 reveal_type(publisher.books2)  # E: Revealed type is 'django.db.models.manager.RelatedManager[main.Book]'
+[out]
+main:16: error: Revealed type is 'Any'
+main:16: error: "Publisher" has no attribute "books"; maybe "books2"?
+[/CASE]