fix mypy issues, add mypy to linting

Author: rhpvorderman

src/isal/isal_zlib.pyi

@@ -50,25 +50,26 @@ class IsalError(OSError): ...
 
 error: IsalError
 
-def adler32(data, value: int) -> int: ...
-def crc32(data, value: int) -> int: ...
+def adler32(data, value: int = ...) -> int: ...
+def crc32(data, value: int = ...) -> int: ...
 
-def compress(data, level: int, wbits: int) -> bytes: ...
-def decompress(data, wbits: int, bufsize: int) -> bytes: ...
+def compress(data, level: int = ..., wbits: int = ...) -> bytes: ...
+def decompress(data, wbits: int = ..., bufsize: int = ...) -> bytes: ...
 
 class Compress:
     def compress(self, data) -> bytes: ...
-    def flush(self, mode: int) -> bytes: ...
+    def flush(self, mode: int = ...) -> bytes: ...
 
 class Decompress:
     unused_data: bytes
     unconsumed_tail: bytes
     eof: bool
     crc: int
 
-    def decompress(self, data, max_length: int) -> bytes: ...
-    def flush(self, length: int) -> bytes: ...
+    def decompress(self, data, max_length: int = ...) -> bytes: ...
+    def flush(self, length: int = ...) -> bytes: ...
 
-def compressobj(level: int, method: int, wbits: int, memLevel: int,
-                strategy: int, zdict) -> Compress: ...
-def decompressobj(wbits: int, zdict) -> Decompress: ...
+def compressobj(level: int = ..., method: int = ..., wbits: int = ...,
+                memLevel: int = ..., strategy: int = ..., zdict = ...
+                ) -> Compress: ...
+def decompressobj(wbits: int = ..., zdict = ...) -> Decompress: ...

tests/test_gzip_compliance.py

@@ -26,8 +26,8 @@
 import tempfile
 import unittest
 from subprocess import PIPE, Popen
-from test.support import _4G, bigmemtest
-from test.support.script_helper import assert_python_failure, assert_python_ok
+from test.support import _4G, bigmemtest  # type: ignore
+from test.support.script_helper import assert_python_failure, assert_python_ok  # type: ignore  # noqa: E501
 
 from isal import igzip
 

tests/test_zlib_compliance.py

@@ -19,8 +19,8 @@
 import random
 import sys
 import unittest
-from test import support
-from test.support import _1G, _4G, bigmemtest
+from test import support  # type: ignore
+from test.support import _1G, _4G, bigmemtest  # type: ignore
 
 import isal
 from isal import isal_zlib

tox.ini

@@ -39,13 +39,14 @@ commands=
     pytest tests/test_isal.py
 
 [testenv:lint]
+# pytest dep needed for mypy check
 deps=flake8
      flake8-import-order
      mypy
-# Linting does not need the installed package.
-skip_install=true
+     pytest
 commands =
     flake8 src tests setup.py benchmark.py
+    mypy src/ tests/
 
 # Documentation should build on python version 3
 [testenv:docs]