Add small bit of type hinting

src/rez/config.py

@@ -1,6 +1,14 @@
 # SPDX-License-Identifier: Apache-2.0
 # Copyright Contributors to the Rez Project
 
+import os
+import re
+import copy
+
+from contextlib import contextmanager
+from functools import lru_cache
+from inspect import ismodule
+import typing
 
 from rez import __version__
 from rez.utils.data_utils import AttrDictWrapper, RO_AttrDictWrapper, \
@@ -16,12 +24,6 @@
 from rez.vendor import yaml
 from rez.vendor.yaml.error import YAMLError
 import rez.deprecations
-from contextlib import contextmanager
-from functools import lru_cache
-from inspect import ismodule
-import os
-import re
-import copy
 
 
 class _Deprecation(object):
@@ -802,7 +804,7 @@ def _get_new_session_popen_args(self):
 
 class _PluginConfigs(object):
     """Lazy config loading for plugins."""
-    def __init__(self, plugin_data):
+    def __init__(self, plugin_data: typing.Dict[str, typing.Any]):
         self.__dict__['_data'] = plugin_data
 
     def __setattr__(self, attr, value):

src/rez/plugin_managers.py

@@ -5,22 +5,26 @@
 """
 Manages loading of all types of Rez plugins.
 """
+import pkgutil
+import os.path
+import sys
+from types import ModuleType
+from typing import Dict, ItemsView, List, KeysView, Optional, Type
+from zipimport import zipimporter
+
 from rez.config import config, expand_system_vars, _load_config_from_filepaths
 from rez.utils.formatting import columnise
 from rez.utils.schema import dict_to_schema
 from rez.utils.data_utils import LazySingleton, cached_property, deep_update
 from rez.utils.logging_ import print_debug, print_warning
+from rez.vendor.schema.schema import Schema
 from rez.exceptions import RezPluginError
-from zipimport import zipimporter
-import pkgutil
-import os.path
-import sys
 
 
 # modified from pkgutil standard library:
 # this function is called from the __init__.py files of each plugin type inside
 # the 'rezplugins' package.
-def extend_path(path, name):
+def extend_path(path: List[str], name: str):
     """Extend a package's path.
 
     Intended use is to place the following code in a package's __init__.py:
@@ -85,23 +89,23 @@ class RezPluginType(object):
     'type_name' must correspond with one of the source directories found under
     the 'plugins' directory.
     """
-    type_name = None
+    type_name: Optional[str] = None
 
     def __init__(self):
         if self.type_name is None:
             raise TypeError("Subclasses of RezPluginType must provide a "
                             "'type_name' attribute")
-        self.pretty_type_name = self.type_name.replace('_', ' ')
-        self.plugin_classes = {}
-        self.failed_plugins = {}
-        self.plugin_modules = {}
-        self.config_data = {}
+        self.pretty_type_name: str = self.type_name.replace('_', ' ')
+        self.plugin_classes: Dict[str, Type[object]] = {}
+        self.failed_plugins: Dict[str, str] = {}
+        self.plugin_modules: Dict[str, ModuleType] = {}
+        self.config_data: Dict[str, Dict] = {}
         self.load_plugins()
 
     def __repr__(self):
         return '%s(%s)' % (self.__class__.__name__, self.plugin_classes.keys())
 
-    def register_plugin(self, plugin_name, plugin_class, plugin_module):
+    def register_plugin(self, plugin_name: str, plugin_class: Type[object], plugin_module: ModuleType):
         # TODO: check plugin_class to ensure it is a sub-class of expected base-class?
         # TODO: perhaps have a Plugin base class. This introduces multiple
         # inheritance in Shell class though :/
@@ -205,15 +209,15 @@ def load_plugins(self):
             data, _ = _load_config_from_filepaths([os.path.join(path, "rezconfig")])
             deep_update(self.config_data, data)
 
-    def get_plugin_class(self, plugin_name):
+    def get_plugin_class(self, plugin_name: str) -> Type[object]:
         """Returns the class registered under the given plugin name."""
         try:
             return self.plugin_classes[plugin_name]
         except KeyError:
             raise RezPluginError("Unrecognised %s plugin: '%s'"
                                  % (self.pretty_type_name, plugin_name))
 
-    def get_plugin_module(self, plugin_name):
+    def get_plugin_module(self, plugin_name: str) -> ModuleType:
         """Returns the module containing the plugin of the given name."""
         try:
             return self.plugin_modules[plugin_name]
@@ -222,7 +226,7 @@ def get_plugin_module(self, plugin_name):
                                  % (self.pretty_type_name, plugin_name))
 
     @cached_property
-    def config_schema(self):
+    def config_schema(self) -> Schema:
         """Returns the merged configuration data schema for this plugin
         type."""
         from rez.config import _plugin_config_dict
@@ -235,9 +239,9 @@ def config_schema(self):
                 deep_update(d, d_)
         return dict_to_schema(d, required=True, modifier=expand_system_vars)
 
-    def create_instance(self, plugin, **instance_kwargs):
+    def create_instance(self, plugin_name: str, **instance_kwargs) -> object:
         """Create and return an instance of the given plugin."""
-        return self.get_plugin_class(plugin)(**instance_kwargs)
+        return self.get_plugin_class(plugin_name)(**instance_kwargs)
 
 
 class RezPluginManager(object):
@@ -294,7 +298,7 @@ def register_plugin():
             'rezplugins' is always found first.
     """
     def __init__(self):
-        self._plugin_types = {}
+        self._plugin_types: Dict[str, LazySingleton] = {}
 
     @cached_property
     def rezplugins_module_paths(self):
@@ -329,53 +333,53 @@ def rezplugins_module_paths(self):
 
     # -- plugin types
 
-    def _get_plugin_type(self, plugin_type):
+    def _get_plugin_type(self, plugin_type: str) -> RezPluginType:
         try:
             return self._plugin_types[plugin_type]()
         except KeyError:
             raise RezPluginError("Unrecognised plugin type: '%s'"
                                  % plugin_type)
 
-    def register_plugin_type(self, type_class):
+    def register_plugin_type(self, type_class: Type[RezPluginType]):
         if not issubclass(type_class, RezPluginType):
             raise TypeError("'type_class' must be a RezPluginType sub class")
         if type_class.type_name is None:
             raise TypeError("Subclasses of RezPluginType must provide a "
                             "'type_name' attribute")
         self._plugin_types[type_class.type_name] = LazySingleton(type_class)
 
-    def get_plugin_types(self):
+    def get_plugin_types(self) -> KeysView[str]:
         """Return a list of the registered plugin types."""
         return self._plugin_types.keys()
 
     # -- plugins
 
-    def get_plugins(self, plugin_type):
+    def get_plugins(self, plugin_type: str) -> KeysView[str]:
         """Return a list of the registered names available for the given plugin
         type."""
         return self._get_plugin_type(plugin_type).plugin_classes.keys()
 
-    def get_plugin_class(self, plugin_type, plugin_name):
+    def get_plugin_class(self, plugin_type: str, plugin_name: str) -> Type[object]:
         """Return the class registered under the given plugin name."""
         plugin = self._get_plugin_type(plugin_type)
         return plugin.get_plugin_class(plugin_name)
 
-    def get_plugin_module(self, plugin_type, plugin_name):
+    def get_plugin_module(self, plugin_type: str, plugin_name: str) -> ModuleType:
         """Return the module defining the class registered under the given
         plugin name."""
         plugin = self._get_plugin_type(plugin_type)
         return plugin.get_plugin_module(plugin_name)
 
-    def get_plugin_config_data(self, plugin_type):
+    def get_plugin_config_data(self, plugin_type: str) -> Dict[str, Dict]:
         """Return the merged configuration data for the plugin type."""
         plugin = self._get_plugin_type(plugin_type)
         return plugin.config_data
 
-    def get_plugin_config_schema(self, plugin_type):
+    def get_plugin_config_schema(self, plugin_type: str) -> Schema:
         plugin = self._get_plugin_type(plugin_type)
         return plugin.config_schema
 
-    def get_failed_plugins(self, plugin_type):
+    def get_failed_plugins(self, plugin_type: str) -> ItemsView[str, str]:
         """Return a list of plugins for the given type that failed to load.
 
         Returns:
@@ -385,12 +389,12 @@ def get_failed_plugins(self, plugin_type):
         """
         return self._get_plugin_type(plugin_type).failed_plugins.items()
 
-    def create_instance(self, plugin_type, plugin_name, **instance_kwargs):
+    def create_instance(self, plugin_type: str, plugin_name: str, **instance_kwargs) -> object:
         """Create and return an instance of the given plugin."""
         plugin_type = self._get_plugin_type(plugin_type)
         return plugin_type.create_instance(plugin_name, **instance_kwargs)
 
-    def get_summary_string(self):
+    def get_summary_string(self) -> str:
         """Get a formatted string summarising the plugins that were loaded."""
         rows = [["PLUGIN TYPE", "NAME", "DESCRIPTION", "STATUS"],
                 ["-----------", "----", "-----------", "------"]]