move configuration to [mypy.plugins.django-stubs] inside mypy config file

mypy_django_plugin/django/context.py

@@ -10,6 +10,7 @@ from django.db.models.fields.reverse_related import ForeignObjectRel
 from django.db.models.sql.query import Query
 from django.utils.functional import cached_property
 from mypy.checker import TypeChecker
+from mypy.errors import Errors
 from mypy.types import Instance, Type as MypyType
 
 from django.contrib.postgres.fields import ArrayField
@@ -139,13 +140,11 @@ class DjangoLookupsContext:
 
 
 class DjangoContext:
-    def __init__(self, plugin_toml_config: Optional[Dict[str, Any]]) -> None:
+    def __init__(self, django_settings_module: str) -> None:
         self.fields_context = DjangoFieldsContext(self)
         self.lookups_context = DjangoLookupsContext(self)
 
-        self.django_settings_module = None
-        if plugin_toml_config:
-            self.django_settings_module = plugin_toml_config.get('django_settings_module', None)
+        self.django_settings_module = django_settings_module
 
         self.apps_registry: Optional[Dict[str, str]] = None
         self.settings: LazySettings = None

mypy_django_plugin/main.py

@@ -1,9 +1,9 @@
-import os
+import configparser
 from functools import partial
 from typing import Callable, Dict, List, Optional, Tuple
 
-import toml
 from django.db.models.fields.related import RelatedField
+from mypy.errors import Errors
 from mypy.nodes import MypyFile, TypeInfo
 from mypy.options import Options
 from mypy.plugin import (
@@ -47,17 +47,33 @@ def add_new_manager_base(ctx: ClassDefContext) -> None:
         helpers.get_django_metadata(sym.node)['manager_bases'][ctx.cls.fullname] = 1
 
 
+def extract_django_settings_module(config_file_path: Optional[str]) -> str:
+    errors = Errors()
+    if config_file_path is None:
+        errors.report(0, None, "'django_settings_module' is not set: no mypy config file specified")
+        errors.raise_error()
+
+    parser = configparser.ConfigParser()
+    parser.read(config_file_path)
+
+    if not parser.has_section('mypy.plugins.django-stubs'):
+        errors.report(0, None, "'django_settings_module' is not set: no section [mypy.plugins.django-stubs]",
+                      file=config_file_path)
+        errors.raise_error()
+    if not parser.has_option('mypy.plugins.django-stubs', 'django_settings_module'):
+        errors.report(0, None, "'django_settings_module' is not set: setting is not provided",
+                      file=config_file_path)
+        errors.raise_error()
+
+    django_settings_module = parser.get('mypy.plugins.django-stubs', 'django_settings_module').strip('\'"')
+    return django_settings_module
+
+
 class NewSemanalDjangoPlugin(Plugin):
     def __init__(self, options: Options) -> None:
         super().__init__(options)
-
-        plugin_toml_config = None
-        if os.path.exists('pyproject.toml'):
-            with open('pyproject.toml', 'r') as f:
-                pyproject_toml = toml.load(f)
-                plugin_toml_config = pyproject_toml.get('tool', {}).get('django-stubs')
-
-        self.django_context = DjangoContext(plugin_toml_config)
+        django_settings_module = extract_django_settings_module(options.config_file)
+        self.django_context = DjangoContext(django_settings_module)
 
     def _get_current_queryset_bases(self) -> Dict[str, int]:
         model_sym = self.lookup_fully_qualified(fullnames.QUERYSET_CLASS_FULLNAME)