Begin mypy type-checking (#229)

* mypy config
* narrow initial type-checking
* add type stubs
* allow any generics
* compat typing
* make types
* add type check step to `make test`
* pre-commit fixes
* remove explicit override

this would require depending on typing_extensions

* exceptions
* implicity rexport
* type ignores
* remove unused
* formatting

---------

Co-authored-by: Giorgio Salluzzo <giorgio.salluzzo@gmail.com>

Makefile

@@ -18,7 +18,12 @@ setup: develop
 
 develop: install-dev-requirements install-test-requirements
 
-test:
+types:
+	@echo "Type checking Python files"
+	.venv/bin/mypy --pretty
+	@echo ""
+
+test: types
 	@echo "Running Python tests"
 	export VIRTUAL_ENV=.venv; .venv/bin/wait-for-it --service httpbin.local:443 --service localhost:6379 --timeout 5 -- .venv/bin/pytest tests/ || exit 1
 	@echo ""

mocket/compat.py

@@ -1,27 +1,30 @@
+from __future__ import annotations
+
 import codecs
 import os
 import shlex
+from typing import Any, Final
 
-ENCODING = os.getenv("MOCKET_ENCODING", "utf-8")
+ENCODING: Final[str] = os.getenv("MOCKET_ENCODING", "utf-8")
 
 text_type = str
 byte_type = bytes
 basestring = (str,)
 
 
-def encode_to_bytes(s, encoding=ENCODING):
+def encode_to_bytes(s: str | bytes, encoding: str = ENCODING) -> bytes:
     if isinstance(s, text_type):
         s = s.encode(encoding)
     return byte_type(s)
 
 
-def decode_from_bytes(s, encoding=ENCODING):
+def decode_from_bytes(s: str | bytes, encoding: str = ENCODING) -> str:
     if isinstance(s, byte_type):
         s = codecs.decode(s, encoding, "ignore")
     return text_type(s)
 
 
-def shsplit(s):
+def shsplit(s: str | bytes) -> list[str]:
     s = decode_from_bytes(s)
     return shlex.split(s)
 

mocket/utils.py

@@ -1,17 +1,26 @@
+from __future__ import annotations
+
 import binascii
 import io
 import os
 import ssl
-from typing import Tuple, Union
+from typing import TYPE_CHECKING, Any, Callable, ClassVar
 
 from .compat import decode_from_bytes, encode_to_bytes
 from .exceptions import StrictMocketException
 
+if TYPE_CHECKING:
+    from _typeshed import ReadableBuffer
+    from typing_extensions import NoReturn
+
 SSL_PROTOCOL = ssl.PROTOCOL_TLSv1_2
 
 
 class MocketSocketCore(io.BytesIO):
-    def write(self, content):
+    def write(  # type: ignore[override] # BytesIO returns int
+        self,
+        content: ReadableBuffer,
+    ) -> None:
         super(MocketSocketCore, self).write(content)
 
         from mocket import Mocket
@@ -20,7 +29,7 @@ def write(self, content):
             os.write(Mocket.w_fd, content)
 
 
-def hexdump(binary_string):
+def hexdump(binary_string: bytes) -> str:
     r"""
     >>> hexdump(b"bar foobar foo") == decode_from_bytes(encode_to_bytes("62 61 72 20 66 6F 6F 62 61 72 20 66 6F 6F"))
     True
@@ -29,7 +38,7 @@ def hexdump(binary_string):
     return " ".join(a + b for a, b in zip(bs[::2], bs[1::2]))
 
 
-def hexload(string):
+def hexload(string: str) -> bytes:
     r"""
     >>> hexload("62 61 72 20 66 6F 6F 62 61 72 20 66 6F 6F") == encode_to_bytes("bar foobar foo")
     True
@@ -38,39 +47,40 @@ def hexload(string):
     return encode_to_bytes(binascii.unhexlify(string_no_spaces))
 
 
-def get_mocketize(wrapper_):
+def get_mocketize(wrapper_: Callable) -> Callable:
     import decorator
 
-    if decorator.__version__ < "5":  # pragma: no cover
+    if decorator.__version__ < "5":  # type: ignore[attr-defined] # pragma: no cover
         return decorator.decorator(wrapper_)
-    return decorator.decorator(wrapper_, kwsyntax=True)
+    return decorator.decorator(  # type: ignore[call-arg] # kwsyntax
+        wrapper_,
+        kwsyntax=True,
+    )
 
 
 class MocketMode:
-    __shared_state = {}
-    STRICT = None
-    STRICT_ALLOWED = None
+    __shared_state: ClassVar[dict[str, Any]] = {}
+    STRICT: ClassVar = None
+    STRICT_ALLOWED: ClassVar = None
 
-    def __init__(self):
+    def __init__(self) -> None:
         self.__dict__ = self.__shared_state
 
-    def is_allowed(self, location: Union[str, Tuple[str, int]]) -> bool:
+    def is_allowed(self, location: str | tuple[str, int]) -> bool:
         """
         Checks if (`host`, `port`) or at least `host`
         are allowed locations to perform real `socket` calls
         """
         if not self.STRICT:
             return True
-        try:
-            host, _ = location
-        except ValueError:
-            host = None
-        return location in self.STRICT_ALLOWED or (
-            host is not None and host in self.STRICT_ALLOWED
-        )
+
+        host_allowed = False
+        if isinstance(location, tuple):
+            host_allowed = location[0] in self.STRICT_ALLOWED
+        return host_allowed or location in self.STRICT_ALLOWED
 
     @staticmethod
-    def raise_not_allowed():
+    def raise_not_allowed() -> NoReturn:
         from .mocket import Mocket
 
         current_entries = [

pyproject.toml

@@ -55,6 +55,8 @@ test = [
     "twine",
     "fastapi",
     "wait-for-it",
+    "mypy",
+    "types-decorator",
 ]
 speedups = [
     "xxhash;platform_python_implementation=='CPython'",
@@ -81,3 +83,27 @@ include = [
 exclude = [
   ".*",
 ]
+
+[tool.mypy]
+python_version = "3.8"
+files = [
+    "mocket/exceptions.py",
+    "mocket/compat.py",
+    "mocket/utils.py",
+    # "tests/"
+    ]
+strict = true
+warn_unused_configs = true
+ignore_missing_imports = true
+warn_redundant_casts = true
+warn_unused_ignores = true
+show_error_codes = true
+implicit_reexport = true
+disallow_any_generics = false
+follow_imports = "silent"  # enable this once majority is typed
+enable_error_code = ['ignore-without-code']
+disable_error_code = ["no-untyped-def"] # enable this once full type-coverage is reached
+
+[[tool.mypy.overrides]]
+module = "tests.*"
+disable_error_code = ['type-arg', 'no-untyped-def']