WIP: An assortment of type annotations

src/_pytest/assertion/__init__.py

@@ -9,12 +9,13 @@
 from _pytest.assertion import util
 from _pytest.compat import TYPE_CHECKING
 from _pytest.config import hookimpl
+from _pytest.config.argparsing import Parser
 
 if TYPE_CHECKING:
     from _pytest.main import Session
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("debugconfig")
     group.addoption(
         "--assert",
@@ -162,7 +163,7 @@ def call_assertion_pass_hook(lineno, orig, expl):
     util._reprcompare, util._assertion_pass = saved_assert_hooks
 
 
-def pytest_sessionfinish(session):
+def pytest_sessionfinish(session: "Session") -> None:
     assertstate = getattr(session.config, "_assertstate", None)
     if assertstate:
         if assertstate.hook is not None:

src/_pytest/cacheprovider.py

@@ -8,6 +8,8 @@
 import os
 from collections import OrderedDict
 from typing import List
+from typing import Optional
+from typing import Union
 
 import attr
 import py
@@ -19,6 +21,8 @@
 from _pytest import nodes
 from _pytest._io import TerminalWriter
 from _pytest.config import Config
+from _pytest.config import ExitCode
+from _pytest.config.argparsing import Parser
 from _pytest.main import Session
 
 README_CONTENT = """\
@@ -264,7 +268,7 @@ def pytest_collection_modifyitems(self, session, config, items):
             else:
                 self._report_status += "not deselecting items."
 
-    def pytest_sessionfinish(self, session):
+    def pytest_sessionfinish(self, session: Session) -> None:
         config = self.config
         if config.getoption("cacheshow") or hasattr(config, "slaveinput"):
             return
@@ -306,15 +310,15 @@ def pytest_collection_modifyitems(
     def _get_increasing_order(self, items):
         return sorted(items, key=lambda item: item.fspath.mtime(), reverse=True)
 
-    def pytest_sessionfinish(self, session):
+    def pytest_sessionfinish(self, session: Session) -> None:
         config = self.config
         if config.getoption("cacheshow") or hasattr(config, "slaveinput"):
             return
 
         config.cache.set("cache/nodeids", self.cached_nodeids)
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("general")
     group.addoption(
         "--lf",
@@ -372,16 +376,18 @@ def pytest_addoption(parser):
     )
 
 
-def pytest_cmdline_main(config):
+def pytest_cmdline_main(config: Config) -> Optional[Union[int, ExitCode]]:
     if config.option.cacheshow:
         from _pytest.main import wrap_session
 
         return wrap_session(config, cacheshow)
+    return None
 
 
 @pytest.hookimpl(tryfirst=True)
-def pytest_configure(config):
-    config.cache = Cache.for_config(config)
+def pytest_configure(config: Config) -> None:
+    # Type ignored: pending mechanism to store typed objects scoped to config.
+    config.cache = Cache.for_config(config)  # type: ignore # noqa: F821
     config.pluginmanager.register(LFPlugin(config), "lfplugin")
     config.pluginmanager.register(NFPlugin(config), "nfplugin")
 

src/_pytest/capture.py

@@ -18,12 +18,12 @@
 from _pytest.compat import CaptureAndPassthroughIO
 from _pytest.compat import CaptureIO
 from _pytest.config import Config
-from _pytest.fixtures import FixtureRequest
+from _pytest.config.argparsing import Parser
 
 patchsysdict = {0: "stdin", 1: "stdout", 2: "stderr"}
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("general")
     group._addoption(
         "--capture",
@@ -150,7 +150,7 @@ def read_global_capture(self):
 
     @contextlib.contextmanager
     def _capturing_for_request(
-        self, request: FixtureRequest
+        self, request
     ) -> Generator["CaptureFixture", None, None]:
         if self._capture_fixture:
             other_name = next(

src/_pytest/compat.py

@@ -227,7 +227,7 @@ def _bytes_to_ascii(val: bytes) -> str:
     return val.decode("ascii", "backslashreplace")
 
 
-def ascii_escaped(val: Union[bytes, str]):
+def ascii_escaped(val: Union[bytes, str]) -> str:
     """If val is pure ascii, returns it as a str().  Otherwise, escapes
     bytes objects into a sequence of escaped bytes:
 

src/_pytest/config/__init__.py

@@ -282,7 +282,7 @@ class PytestPluginManager(PluginManager):
     * ``conftest.py`` loading during start-up;
     """
 
-    def __init__(self):
+    def __init__(self) -> None:
         import _pytest.assertion
 
         super().__init__("pytest")
@@ -362,7 +362,7 @@ def parse_hookspec_opts(self, module_or_class, name):
                 }
         return opts
 
-    def register(self, plugin, name=None):
+    def register(self, plugin: _PluggyPlugin, name: Optional[str] = None):
         if name in _pytest.deprecated.DEPRECATED_EXTERNAL_PLUGINS:
             warnings.warn(
                 PytestConfigWarning(
@@ -391,7 +391,7 @@ def hasplugin(self, name):
         """Return True if the plugin with the given name is registered."""
         return bool(self.get_plugin(name))
 
-    def pytest_configure(self, config):
+    def pytest_configure(self, config: "Config") -> None:
         # XXX now that the pluginmanager exposes hookimpl(tryfirst...)
         # we should remove tryfirst/trylast as markers
         config.addinivalue_line(
@@ -522,7 +522,7 @@ def _importconftest(self, conftestpath):
     #
     #
 
-    def consider_preparse(self, args, *, exclude_only=False):
+    def consider_preparse(self, args, *, exclude_only: bool = False) -> None:
         i = 0
         n = len(args)
         while i < n:
@@ -543,7 +543,7 @@ def consider_preparse(self, args, *, exclude_only=False):
                     continue
                 self.consider_pluginarg(parg)
 
-    def consider_pluginarg(self, arg):
+    def consider_pluginarg(self, arg) -> None:
         if arg.startswith("no:"):
             name = arg[3:]
             if name in essential_plugins:
@@ -568,21 +568,21 @@ def consider_pluginarg(self, arg):
                     del self._name2plugin["pytest_" + name]
             self.import_plugin(arg, consider_entry_points=True)
 
-    def consider_conftest(self, conftestmodule):
+    def consider_conftest(self, conftestmodule) -> None:
         self.register(conftestmodule, name=conftestmodule.__file__)
 
-    def consider_env(self):
+    def consider_env(self) -> None:
         self._import_plugin_specs(os.environ.get("PYTEST_PLUGINS"))
 
-    def consider_module(self, mod):
+    def consider_module(self, mod: types.ModuleType) -> None:
         self._import_plugin_specs(getattr(mod, "pytest_plugins", []))
 
     def _import_plugin_specs(self, spec):
         plugins = _get_plugin_specs_as_list(spec)
         for import_spec in plugins:
             self.import_plugin(import_spec)
 
-    def import_plugin(self, modname, consider_entry_points=False):
+    def import_plugin(self, modname: str, consider_entry_points: bool = False) -> None:
         """
         Imports a plugin with ``modname``. If ``consider_entry_points`` is True, entry point
         names are also considered to find a plugin.
@@ -766,7 +766,12 @@ class InvocationParams:
         plugins = attr.ib()
         dir = attr.ib(type=Path)
 
-    def __init__(self, pluginmanager, *, invocation_params=None) -> None:
+    def __init__(
+        self,
+        pluginmanager: PytestPluginManager,
+        *,
+        invocation_params: Optional[InvocationParams] = None
+    ) -> None:
         from .argparsing import Parser, FILE_OR_DIR
 
         if invocation_params is None:
@@ -796,23 +801,23 @@ def __init__(self, pluginmanager, *, invocation_params=None) -> None:
         )
 
     @property
-    def invocation_dir(self):
+    def invocation_dir(self) -> py.path.local:
         """Backward compatibility"""
         return py.path.local(str(self.invocation_params.dir))
 
-    def add_cleanup(self, func):
+    def add_cleanup(self, func) -> None:
         """ Add a function to be called when the config object gets out of
         use (usually coninciding with pytest_unconfigure)."""
         self._cleanup.append(func)
 
-    def _do_configure(self):
+    def _do_configure(self) -> None:
         assert not self._configured
         self._configured = True
         with warnings.catch_warnings():
             warnings.simplefilter("default")
             self.hook.pytest_configure.call_historic(kwargs=dict(config=self))
 
-    def _ensure_unconfigure(self):
+    def _ensure_unconfigure(self) -> None:
         if self._configured:
             self._configured = False
             self.hook.pytest_unconfigure(config=self)
@@ -824,7 +829,9 @@ def _ensure_unconfigure(self):
     def get_terminal_writer(self):
         return self.pluginmanager.get_plugin("terminalreporter")._tw
 
-    def pytest_cmdline_parse(self, pluginmanager, args):
+    def pytest_cmdline_parse(
+        self, pluginmanager: PytestPluginManager, args: List[str]
+    ) -> object:
         try:
             self.parse(args)
         except UsageError:

src/_pytest/debugging.py

@@ -4,7 +4,10 @@
 import sys
 
 from _pytest import outcomes
+from _pytest.config import Config
 from _pytest.config import hookimpl
+from _pytest.config import PytestPluginManager
+from _pytest.config.argparsing import Parser
 from _pytest.config.exceptions import UsageError
 
 
@@ -19,7 +22,7 @@ def _validate_usepdb_cls(value):
     return (modname, classname)
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     group = parser.getgroup("general")
     group._addoption(
         "--pdb",
@@ -43,7 +46,7 @@ def pytest_addoption(parser):
     )
 
 
-def pytest_configure(config):
+def pytest_configure(config: Config) -> None:
     import pdb
 
     if config.getvalue("trace"):
@@ -73,8 +76,8 @@ def fin():
 class pytestPDB:
     """ Pseudo PDB that defers to the real pdb. """
 
-    _pluginmanager = None
-    _config = None
+    _pluginmanager = None  # type: PytestPluginManager
+    _config = None  # type: Config
     _saved = []  # type: list
     _recursive_debug = 0
     _wrapped_pdb_cls = None

src/_pytest/doctest.py

@@ -7,6 +7,7 @@
 import warnings
 from contextlib import contextmanager
 from typing import Dict
+from typing import Iterable
 from typing import List
 from typing import Optional
 from typing import Sequence
@@ -23,6 +24,7 @@
 from _pytest._io import TerminalWriter
 from _pytest.compat import safe_getattr
 from _pytest.compat import TYPE_CHECKING
+from _pytest.config.argparsing import Parser
 from _pytest.fixtures import FixtureRequest
 from _pytest.outcomes import Skipped
 from _pytest.python_api import approx
@@ -52,7 +54,7 @@
 CHECKER_CLASS = None  # type: Optional[Type[doctest.OutputChecker]]
 
 
-def pytest_addoption(parser):
+def pytest_addoption(parser: Parser) -> None:
     parser.addini(
         "doctest_optionflags",
         "option flags for doctests",
@@ -102,19 +104,24 @@ def pytest_addoption(parser):
     )
 
 
-def pytest_unconfigure():
+def pytest_unconfigure() -> None:
     global RUNNER_CLASS
 
     RUNNER_CLASS = None
 
 
-def pytest_collect_file(path, parent):
+def pytest_collect_file(
+    path: py.path.local, parent
+) -> Optional[Union["DoctestModule", "DoctestTextfile"]]:
     config = parent.config
     if path.ext == ".py":
         if config.option.doctestmodules and not _is_setup_py(config, path, parent):
-            return DoctestModule.from_parent(parent, fspath=path)
+            mod = DoctestModule.from_parent(parent, fspath=path)  # type: DoctestModule
+            return mod
     elif _is_doctest(config, path, parent):
-        return DoctestTextfile.from_parent(parent, fspath=path)
+        txt = DoctestTextfile.from_parent(parent, fspath=path)  # type: DoctestTextfile
+        return txt
+    return None
 
 
 def _is_setup_py(config, path, parent):
@@ -361,7 +368,7 @@ def _get_continue_on_failure(config):
 class DoctestTextfile(pytest.Module):
     obj = None
 
-    def collect(self):
+    def collect(self) -> Iterable[DoctestItem]:
         import doctest
 
         # inspired by doctest.testfile; ideally we would use it directly,
@@ -440,7 +447,7 @@ def _mock_aware_unwrap(obj, stop=None):
 
 
 class DoctestModule(pytest.Module):
-    def collect(self):
+    def collect(self) -> Iterable[DoctestItem]:
         import doctest
 
         class MockAwareDocTestFinder(doctest.DocTestFinder):