add BaseManager.create() typechecking

mypy_django_plugin/plugins/fields.py

@@ -1,7 +1,12 @@
+from typing import cast
+
+from mypy.checker import TypeChecker
+from mypy.nodes import ListExpr, NameExpr, TupleExpr
 from mypy.plugin import FunctionContext
-from mypy.types import Type, Instance
+from mypy.types import Instance, TupleType, Type
 
 from mypy_django_plugin import helpers
+from mypy_django_plugin.plugins.models import iter_over_assignments
 
 
 def determine_type_of_array_field(ctx: FunctionContext) -> Type:
@@ -16,3 +21,54 @@ def determine_type_of_array_field(ctx: FunctionContext) -> Type:
 
     return ctx.api.named_generic_type(ctx.context.callee.fullname,
                                       args=[get_method.type.ret_type])
+
+
+def record_field_properties_into_outer_model_class(ctx: FunctionContext) -> Type:
+    api = cast(TypeChecker, ctx.api)
+    outer_model = api.scope.active_class()
+    if outer_model is None or not outer_model.has_base(helpers.MODEL_CLASS_FULLNAME):
+        # outside models.Model class, undetermined
+        return ctx.default_return_type
+
+    field_name = None
+    for name_expr, stmt in iter_over_assignments(outer_model.defn):
+        if stmt == ctx.context and isinstance(name_expr, NameExpr):
+            field_name = name_expr.name
+            break
+    if field_name is None:
+        return ctx.default_return_type
+
+    fields_metadata = outer_model.metadata.setdefault('django', {}).setdefault('fields', {})
+
+    # primary key
+    is_primary_key = False
+    primary_key_arg = helpers.get_argument_by_name(ctx, 'primary_key')
+    if primary_key_arg:
+        is_primary_key = helpers.parse_bool(primary_key_arg)
+    fields_metadata[field_name] = {'primary_key': is_primary_key}
+
+    # choices
+    choices_arg = helpers.get_argument_by_name(ctx, 'choices')
+    if choices_arg and isinstance(choices_arg, (TupleExpr, ListExpr)):
+        # iterable of 2 element tuples of two kinds
+        _, analyzed_choices = api.analyze_iterable_item_type(choices_arg)
+        if isinstance(analyzed_choices, TupleType):
+            first_element_type = analyzed_choices.items[0]
+            if isinstance(first_element_type, Instance):
+                fields_metadata[field_name]['choices'] = first_element_type.type.fullname()
+
+    # nullability
+    null_arg = helpers.get_argument_by_name(ctx, 'null')
+    is_nullable = False
+    if null_arg:
+        is_nullable = helpers.parse_bool(null_arg)
+    fields_metadata[field_name]['null'] = is_nullable
+
+    # is_blankable
+    blank_arg = helpers.get_argument_by_name(ctx, 'blank')
+    is_blankable = False
+    if blank_arg:
+        is_blankable = helpers.parse_bool(blank_arg)
+    fields_metadata[field_name]['blank'] = is_blankable
+
+    return ctx.default_return_type