Add more type annotations

.pre-commit-config.yaml

@@ -18,7 +18,7 @@ repos:
         args: [--remove]
     -   id: check-yaml
     -   id: debug-statements
-        exclude: _pytest/debugging.py
+        exclude: _pytest/(debugging|hookspec).py
         language_version: python3
 -   repo: https://gitlab.com/pycqa/flake8
     rev: 3.8.2

setup.cfg

@@ -91,6 +91,7 @@ formats = sdist.tgz,bdist_wheel
 
 [mypy]
 mypy_path = src
+check_untyped_defs = True
 ignore_missing_imports = True
 no_implicit_optional = True
 show_error_codes = True

src/_pytest/_code/code.py

@@ -15,6 +15,7 @@
 from typing import Generic
 from typing import Iterable
 from typing import List
+from typing import Mapping
 from typing import Optional
 from typing import Pattern
 from typing import Sequence
@@ -46,7 +47,7 @@
     from typing_extensions import Literal
     from weakref import ReferenceType
 
-    _TracebackStyle = Literal["long", "short", "line", "no", "native", "value"]
+    _TracebackStyle = Literal["long", "short", "line", "no", "native", "value", "auto"]
 
 
 class Code:
@@ -728,7 +729,7 @@ def get_exconly(
                 failindent = indentstr
         return lines
 
-    def repr_locals(self, locals: Dict[str, object]) -> Optional["ReprLocals"]:
+    def repr_locals(self, locals: Mapping[str, object]) -> Optional["ReprLocals"]:
         if self.showlocals:
             lines = []
             keys = [loc for loc in locals if loc[0] != "@"]

src/_pytest/_io/saferepr.py

@@ -1,9 +1,12 @@
 import pprint
 import reprlib
 from typing import Any
+from typing import Dict
+from typing import IO
+from typing import Optional
 
 
-def _try_repr_or_str(obj):
+def _try_repr_or_str(obj: object) -> str:
     try:
         return repr(obj)
     except (KeyboardInterrupt, SystemExit):
@@ -12,7 +15,7 @@ def _try_repr_or_str(obj):
         return '{}("{}")'.format(type(obj).__name__, obj)
 
 
-def _format_repr_exception(exc: BaseException, obj: Any) -> str:
+def _format_repr_exception(exc: BaseException, obj: object) -> str:
     try:
         exc_info = _try_repr_or_str(exc)
     except (KeyboardInterrupt, SystemExit):
@@ -42,7 +45,7 @@ def __init__(self, maxsize: int) -> None:
         self.maxstring = maxsize
         self.maxsize = maxsize
 
-    def repr(self, x: Any) -> str:
+    def repr(self, x: object) -> str:
         try:
             s = super().repr(x)
         except (KeyboardInterrupt, SystemExit):
@@ -51,7 +54,7 @@ def repr(self, x: Any) -> str:
             s = _format_repr_exception(exc, x)
         return _ellipsize(s, self.maxsize)
 
-    def repr_instance(self, x: Any, level: int) -> str:
+    def repr_instance(self, x: object, level: int) -> str:
         try:
             s = repr(x)
         except (KeyboardInterrupt, SystemExit):
@@ -61,7 +64,7 @@ def repr_instance(self, x: Any, level: int) -> str:
         return _ellipsize(s, self.maxsize)
 
 
-def safeformat(obj: Any) -> str:
+def safeformat(obj: object) -> str:
     """return a pretty printed string for the given object.
     Failing __repr__ functions of user instances will be represented
     with a short exception info.
@@ -72,7 +75,7 @@ def safeformat(obj: Any) -> str:
         return _format_repr_exception(exc, obj)
 
 
-def saferepr(obj: Any, maxsize: int = 240) -> str:
+def saferepr(obj: object, maxsize: int = 240) -> str:
     """return a size-limited safe repr-string for the given object.
     Failing __repr__ functions of user instances will be represented
     with a short exception info and 'saferepr' generally takes
@@ -85,19 +88,39 @@ def saferepr(obj: Any, maxsize: int = 240) -> str:
 class AlwaysDispatchingPrettyPrinter(pprint.PrettyPrinter):
     """PrettyPrinter that always dispatches (regardless of width)."""
 
-    def _format(self, object, stream, indent, allowance, context, level):
-        p = self._dispatch.get(type(object).__repr__, None)
+    def _format(
+        self,
+        object: object,
+        stream: IO[str],
+        indent: int,
+        allowance: int,
+        context: Dict[int, Any],
+        level: int,
+    ) -> None:
+        # Type ignored because _dispatch is private.
+        p = self._dispatch.get(type(object).__repr__, None)  # type: ignore[attr-defined] # noqa: F821
 
         objid = id(object)
         if objid in context or p is None:
-            return super()._format(object, stream, indent, allowance, context, level)
+            # Type ignored because _format is private.
+            super()._format(  # type: ignore[misc] # noqa: F821
+                object, stream, indent, allowance, context, level,
+            )
+            return
 
         context[objid] = 1
         p(self, object, stream, indent, allowance, context, level + 1)
         del context[objid]
 
 
-def _pformat_dispatch(object, indent=1, width=80, depth=None, *, compact=False):
+def _pformat_dispatch(
+    object: object,
+    indent: int = 1,
+    width: int = 80,
+    depth: Optional[int] = None,
+    *,
+    compact: bool = False
+) -> str:
     return AlwaysDispatchingPrettyPrinter(
         indent=indent, width=width, depth=depth, compact=compact
     ).pformat(object)

src/_pytest/assertion/__init__.py

@@ -3,6 +3,7 @@
 """
 import sys
 from typing import Any
+from typing import Generator
 from typing import List
 from typing import Optional
 
@@ -13,12 +14,14 @@
 from _pytest.compat import TYPE_CHECKING
 from _pytest.config import Config
 from _pytest.config import hookimpl
+from _pytest.config.argparsing import Parser
+from _pytest.nodes import Item
 
 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",
@@ -43,7 +46,7 @@ def pytest_addoption(parser):
     )
 
 
-def register_assert_rewrite(*names) -> None:
+def register_assert_rewrite(*names: str) -> None:
     """Register one or more module names to be rewritten on import.
 
     This function will make sure that this module or all modules inside
@@ -72,27 +75,27 @@ def register_assert_rewrite(*names) -> None:
 class DummyRewriteHook:
     """A no-op import hook for when rewriting is disabled."""
 
-    def mark_rewrite(self, *names):
+    def mark_rewrite(self, *names: str) -> None:
         pass
 
 
 class AssertionState:
     """State for the assertion plugin."""
 
-    def __init__(self, config, mode):
+    def __init__(self, config: Config, mode) -> None:
         self.mode = mode
         self.trace = config.trace.root.get("assertion")
         self.hook = None  # type: Optional[rewrite.AssertionRewritingHook]
 
 
-def install_importhook(config):
+def install_importhook(config: Config) -> rewrite.AssertionRewritingHook:
     """Try to install the rewrite hook, raise SystemError if it fails."""
     config._store[assertstate_key] = AssertionState(config, "rewrite")
     config._store[assertstate_key].hook = hook = rewrite.AssertionRewritingHook(config)
     sys.meta_path.insert(0, hook)
     config._store[assertstate_key].trace("installed rewrite import hook")
 
-    def undo():
+    def undo() -> None:
         hook = config._store[assertstate_key].hook
         if hook is not None and hook in sys.meta_path:
             sys.meta_path.remove(hook)
@@ -112,7 +115,7 @@ def pytest_collection(session: "Session") -> None:
 
 
 @hookimpl(tryfirst=True, hookwrapper=True)
-def pytest_runtest_protocol(item):
+def pytest_runtest_protocol(item: Item) -> Generator[None, None, None]:
     """Setup the pytest_assertrepr_compare and pytest_assertion_pass hooks
 
     The rewrite module will use util._reprcompare if
@@ -121,8 +124,7 @@ def pytest_runtest_protocol(item):
     comparison for the test.
     """
 
-    def callbinrepr(op, left, right):
-        # type: (str, object, object) -> Optional[str]
+    def callbinrepr(op, left: object, right: object) -> Optional[str]:
         """Call the pytest_assertrepr_compare hook and prepare the result
 
         This uses the first result from the hook and then ensures the
@@ -155,7 +157,7 @@ def callbinrepr(op, left, right):
 
     if item.ihook.pytest_assertion_pass.get_hookimpls():
 
-        def call_assertion_pass_hook(lineno, orig, expl):
+        def call_assertion_pass_hook(lineno: int, orig: str, expl: str) -> None:
             item.ihook.pytest_assertion_pass(
                 item=item, lineno=lineno, orig=orig, expl=expl
             )
@@ -167,7 +169,7 @@ 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 = session.config._store.get(assertstate_key, None)
     if assertstate:
         if assertstate.hook is not None: