Add inline types to Requests

.github/workflows/typecheck.yml

@@ -0,0 +1,29 @@
+name: Type Check
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  typecheck:
+    runs-on: ubuntu-24.04
+    timeout-minutes: 10
+
+    steps:
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      with:
+        persist-credentials: false
+
+    - name: Set up Python
+      uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+      with:
+        python-version: "3.10"
+
+    - name: Install dependencies
+      run: |
+        python -m pip install pip==26.0.1
+        python -m pip install -e . --group typecheck
+
+    - name: Run pyright
+      run: python -m pyright src/requests/

pyproject.toml

@@ -51,14 +51,20 @@ Source = "https://github.com/psf/requests"
 [project.optional-dependencies]
 security = []
 socks = ["PySocks>=1.5.6, !=1.5.7"]
-use_chardet_on_py3 = ["chardet>=3.0.2,<8"]
+use_chardet_on_py3 = ["chardet>=3.0.2,<7"]
+
+[dependency-groups]
 test = [
     "pytest-httpbin==2.1.0",
     "pytest-cov",
     "pytest-mock",
     "pytest-xdist",
     "PySocks>=1.5.6, !=1.5.7",
-    "pytest>=3"
+    "pytest>=3",
+]
+typecheck = [
+    "pyright",
+    "typing_extensions",
 ]
 
 [tool.setuptools]
@@ -100,3 +106,8 @@ addopts = "--doctest-modules"
 doctest_optionflags = "NORMALIZE_WHITESPACE ELLIPSIS"
 minversion = "6.2"
 testpaths = ["tests"]
+
+
+[tool.pyright]
+include = ["src/requests"]
+typeCheckingMode = "strict"

src/requests/__init__.py

@@ -38,6 +38,8 @@
 :license: Apache 2.0, see LICENSE for more details.
 """
 
+from __future__ import annotations
+
 import warnings
 
 import urllib3
@@ -50,21 +52,25 @@
     charset_normalizer_version = None
 
 try:
-    from chardet import __version__ as chardet_version
+    from chardet import __version__ as chardet_version  # type: ignore[import-not-found]
 except ImportError:
     chardet_version = None
 
 
-def check_compatibility(urllib3_version, chardet_version, charset_normalizer_version):
-    urllib3_version = urllib3_version.split(".")
-    assert urllib3_version != ["dev"]  # Verify urllib3 isn't installed from git.
+def check_compatibility(
+    urllib3_version: str,
+    chardet_version: str | None,
+    charset_normalizer_version: str | None,
+) -> None:
+    urllib3_version_list = urllib3_version.split(".")
+    assert urllib3_version_list != ["dev"]  # Verify urllib3 isn't installed from git.
 
     # Sometimes, urllib3 only reports its version as 16.1.
-    if len(urllib3_version) == 2:
-        urllib3_version.append("0")
+    if len(urllib3_version_list) == 2:
+        urllib3_version_list.append("0")
 
     # Check urllib3 for compatibility.
-    major, minor, patch = urllib3_version  # noqa: F811
+    major, minor, patch = urllib3_version_list  # noqa: F811
     major, minor, patch = int(major), int(minor), int(patch)
     # urllib3 >= 1.21.1
     assert major >= 1
@@ -90,28 +96,28 @@ def check_compatibility(urllib3_version, chardet_version, charset_normalizer_ver
         )
 
 
-def _check_cryptography(cryptography_version):
+def _check_cryptography(cryptography_version: str) -> None:
     # cryptography < 1.3.4
     try:
-        cryptography_version = list(map(int, cryptography_version.split(".")))
+        cryptography_version_list = list(map(int, cryptography_version.split(".")))
     except ValueError:
         return
 
-    if cryptography_version < [1, 3, 4]:
-        warning = (
-            f"Old version of cryptography ({cryptography_version}) may cause slowdown."
-        )
+    if cryptography_version_list < [1, 3, 4]:
+        warning = f"Old version of cryptography ({cryptography_version_list}) may cause slowdown."
         warnings.warn(warning, RequestsDependencyWarning)
 
 
 # Check imported dependencies for compatibility.
 try:
     check_compatibility(
-        urllib3.__version__, chardet_version, charset_normalizer_version
+        urllib3.__version__,  # type: ignore[reportPrivateImportUsage]
+        chardet_version,  # type: ignore[reportUnknownArgumentType]
+        charset_normalizer_version,
     )
 except (AssertionError, ValueError):
     warnings.warn(
-        f"urllib3 ({urllib3.__version__}) or chardet "
+        f"urllib3 ({urllib3.__version__}) or chardet "  # type: ignore[reportPrivateImportUsage]
         f"({chardet_version})/charset_normalizer ({charset_normalizer_version}) "
         "doesn't match a supported version!",
         RequestsDependencyWarning,
@@ -132,9 +138,11 @@ def _check_cryptography(cryptography_version):
         pyopenssl.inject_into_urllib3()
 
         # Check cryptography version
-        from cryptography import __version__ as cryptography_version
+        from cryptography import (  # type: ignore[reportMissingImports]
+            __version__ as cryptography_version,  # type: ignore[reportUnknownVariableType]
+        )
 
-        _check_cryptography(cryptography_version)
+        _check_cryptography(cryptography_version)  # type: ignore[reportUnknownArgumentType]
 except ImportError:
     pass
 
@@ -177,6 +185,34 @@ def _check_cryptography(cryptography_version):
 from .sessions import Session, session
 from .status_codes import codes
 
+__all__ = (
+    "ConnectionError",
+    "ConnectTimeout",
+    "HTTPError",
+    "JSONDecodeError",
+    "PreparedRequest",
+    "ReadTimeout",
+    "Request",
+    "RequestException",
+    "Response",
+    "Session",
+    "Timeout",
+    "TooManyRedirects",
+    "URLRequired",
+    "codes",
+    "delete",
+    "get",
+    "head",
+    "options",
+    "packages",
+    "patch",
+    "post",
+    "put",
+    "request",
+    "session",
+    "utils",
+)
+
 logging.getLogger(__name__).addHandler(NullHandler())
 
 # FileModeWarnings go off per the default.

src/requests/_internal_utils.py

@@ -23,7 +23,7 @@
 }
 
 
-def to_native_string(string, encoding="ascii"):
+def to_native_string(string: str | bytes, encoding: str = "ascii") -> str:
     """Given a string object, regardless of type, returns a representation of
     that string in the native string type, encoding and decoding where
     necessary. This assumes ASCII unless told otherwise.
@@ -36,7 +36,7 @@ def to_native_string(string, encoding="ascii"):
     return out
 
 
-def unicode_is_ascii(u_string):
+def unicode_is_ascii(u_string: str) -> bool:
     """Determine if unicode string only contains ASCII characters.
 
     :param str u_string: unicode string to check. Must be unicode

src/requests/_types.py

@@ -0,0 +1,133 @@
+"""
+requests._types
+~~~~~~~~~~~~~~~
+
+This module contains type aliases used internally by the Requests library.
+These types are not part of the public API and must not be relied upon
+by external code.
+"""
+
+from __future__ import annotations
+
+from collections.abc import Callable, Iterable, Mapping, MutableMapping
+from typing import (
+    TYPE_CHECKING,
+    Any,
+    Protocol,
+    TypeVar,
+    runtime_checkable,
+)
+
+_T_co = TypeVar("_T_co", covariant=True)
+
+
+@runtime_checkable
+class SupportsRead(Protocol[_T_co]):
+    def read(self, length: int = ...) -> _T_co: ...
+
+
+@runtime_checkable
+class SupportsItems(Protocol):
+    def items(self) -> Iterable[tuple[Any, Any]]: ...
+
+
+# These are needed at runtime for default_hooks() return type
+HookType = Callable[["Response"], Any]
+HooksInputType = Mapping[str, "Iterable[HookType] | HookType"]
+
+
+def is_prepared(request: PreparedRequest) -> TypeIs[_ValidatedRequest]:
+    """Verify a PreparedRequest has been fully prepared."""
+    if TYPE_CHECKING:
+        return request.url is not None and request.method is not None
+    # noop at runtime to avoid AssertionError
+    return True
+
+
+if TYPE_CHECKING:
+    from typing import TypeAlias
+
+    from typing_extensions import TypeIs  # move to typing when Python >= 3.13
+
+    from .auth import AuthBase
+    from .cookies import RequestsCookieJar
+    from .models import PreparedRequest, Response
+    from .structures import CaseInsensitiveDict
+
+    class _ValidatedRequest(PreparedRequest):
+        """Subtype asserting a PreparedRequest has been fully prepared before calling.
+
+        The override suppression is required because mutable attribute types are
+        invariant (Liskov), but we only narrow after preparation is complete. This
+        is the explicit contract for Requests but Python's typing doesn't have a
+        better way to represent the requirement.
+        """
+
+        url: str  # type: ignore[reportIncompatibleVariableOverride]
+        method: str  # type: ignore[reportIncompatibleVariableOverride]
+
+    # Type aliases for core API concepts (ordered by request() signature)
+    UriType: TypeAlias = str | bytes
+
+    _ParamsMappingKeyType: TypeAlias = str | bytes | int | float
+    _ParamsMappingValueType: TypeAlias = (
+        str | bytes | int | float | Iterable[str | bytes | int | float] | None
+    )
+    ParamsType: TypeAlias = (
+        Mapping[_ParamsMappingKeyType, _ParamsMappingValueType]
+        | tuple[tuple[_ParamsMappingKeyType, _ParamsMappingValueType], ...]
+        | Iterable[tuple[_ParamsMappingKeyType, _ParamsMappingValueType]]
+        | str
+        | bytes
+        | None
+    )
+
+    KVDataType: TypeAlias = Iterable[tuple[Any, Any]] | Mapping[Any, Any]
+
+    EncodableDataType: TypeAlias = KVDataType | str | bytes | SupportsRead[str | bytes]
+
+    DataType: TypeAlias = (
+        KVDataType
+        | Iterable[bytes | str]
+        | str
+        | bytes
+        | SupportsRead[str | bytes]
+        | None
+    )
+
+    BodyType: TypeAlias = (
+        bytes | str | Iterable[bytes | str] | SupportsRead[bytes | str] | None
+    )
+
+    HeadersType: TypeAlias = CaseInsensitiveDict[str] | Mapping[str, str | bytes]
+    HeadersUpdateType: TypeAlias = Mapping[str, str | bytes | None]
+
+    CookiesType: TypeAlias = RequestsCookieJar | Mapping[str, str]
+
+    # Building blocks for FilesType
+    _FileName: TypeAlias = str | None
+    _FileContent: TypeAlias = SupportsRead[str | bytes] | str | bytes
+    _FileSpecBasic: TypeAlias = tuple[_FileName, _FileContent]
+    _FileSpecWithContentType: TypeAlias = tuple[_FileName, _FileContent, str]
+    _FileSpecWithHeaders: TypeAlias = tuple[
+        _FileName, _FileContent, str, CaseInsensitiveDict[str] | Mapping[str, str]
+    ]
+    _FileSpec: TypeAlias = (
+        _FileContent | _FileSpecBasic | _FileSpecWithContentType | _FileSpecWithHeaders
+    )
+    FilesType: TypeAlias = (
+        Mapping[str, _FileSpec] | Iterable[tuple[str, _FileSpec]] | None
+    )
+
+    AuthType: TypeAlias = (
+        tuple[str, str] | AuthBase | Callable[[PreparedRequest], PreparedRequest] | None
+    )
+
+    TimeoutType: TypeAlias = float | tuple[float | None, float | None] | None
+    ProxiesType: TypeAlias = MutableMapping[str, str]
+    HooksType: TypeAlias = dict[str, list["HookType"]] | None
+    VerifyType: TypeAlias = bool | str
+    CertType: TypeAlias = str | tuple[str, str] | None
+    JsonType: TypeAlias = (
+        None | bool | int | float | str | list["JsonType"] | dict[str, "JsonType"]
+    )