Add --pep561-override option to force packages as typed even they don't have a py.typed file

Author: ntninja

mypy/config_parser.py

@@ -85,6 +85,7 @@ def split_and_match_files(paths: str) -> List[str]:
     'package_root': lambda s: [p.strip() for p in s.split(',')],
     'cache_dir': expand_path,
     'python_executable': expand_path,
+    'pep561_override': lambda s: [p.strip() for p in s.split(',')],
 }  # type: Final
 
 

mypy/main.py

@@ -467,6 +467,10 @@ def add_invertible_flag(flag: str,
     imports_group.add_argument(
         '--no-silence-site-packages', action='store_true',
         help="Do not silence errors in PEP 561 compliant installed packages")
+    imports_group.add_argument(
+        '--pep561-override', action='append', default=[],
+        help="Consider the given package typed even if it does not claim to be "
+             "PEP 561 compatible (may be repeated)")
 
     platform_group = parser.add_argument_group(
         title='Platform configuration',

mypy/modulefinder.py

@@ -168,19 +168,31 @@ def find_module(self, id: str) -> ModuleSearchResult:
 
     def _find_module_non_stub_helper(self, components: List[str],
                                      pkg_dir: str) -> Union[OnePackageDir, ModuleNotFoundReason]:
-        plausible_match = False
+        plausible_match = None  # type: Optional[Tuple[str, OnePackageDir]]
+        plausible_match_is_ns = False
         dir_path = pkg_dir
         for index, component in enumerate(components):
             dir_path = os.path.join(dir_path, component)
             if self.fscache.isfile(os.path.join(dir_path, 'py.typed')):
                 return os.path.join(pkg_dir, *components[:-1]), index == 0
-            elif not plausible_match and (self.fscache.isdir(dir_path)
-                                          or self.fscache.isfile(dir_path + ".py")):
-                plausible_match = True
-        if plausible_match:
-            return ModuleNotFoundReason.FOUND_WITHOUT_TYPE_HINTS
-        else:
+            if not plausible_match or plausible_match_is_ns:
+                have_package_or_mod = self.fscache.isfile(os.path.join(dir_path, '__init__.py')) \
+                                      or self.fscache.isfile(dir_path + ".py")
+                if not have_package_or_mod:
+                    have_ns_package = self.fscache.isdir(dir_path)
+
+                if have_package_or_mod or (not plausible_match_is_ns and have_ns_package):
+                    plausible_match = (
+                        '.'.join(components[:(index + 1)]),
+                        (os.path.join(pkg_dir, *components[:-1]), index == 0)
+                    )
+                    plausible_match_is_ns = not have_package_or_mod
+        if not plausible_match:
             return ModuleNotFoundReason.NOT_FOUND
+        elif self.options and plausible_match[0] in self.options.pep561_override:
+            return plausible_match[1]
+        else:
+            return ModuleNotFoundReason.FOUND_WITHOUT_TYPE_HINTS
 
     def _update_ns_ancestors(self, components: List[str], match: Tuple[str, bool]) -> None:
         path, verify = match

mypy/options.py

@@ -267,6 +267,8 @@ def __init__(self) -> None:
         self.transform_source = None  # type: Optional[Callable[[Any], Any]]
         # Print full path to each file in the report.
         self.show_absolute_path = False  # type: bool
+        # Consider packages typed even if they do not declare PEP-561 compatiblity
+        self.pep561_override = []  # type: List[str]
 
     # To avoid breaking plugin compatibility, keep providing new_semantic_analyzer
     @property