Make mypy run cleanly

docs/contributing.rst

@@ -68,6 +68,9 @@ following are also required for developers to run the test suite manually:
 `pylint <https://pypi.python.org/pypi/pylint>`__
    Code analysis.
 
+`mypy <http://www.mypy-lang.org/>`__
+   Optional static typing for Python.
+
 Code coverage
 ~~~~~~~~~~~~~
 

tests/lint/test_mypy.py

@@ -0,0 +1,24 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# Copyright (c) 2014-2019, Lars Asplund lars.anders.asplund@gmail.com
+
+"""
+MyPy check
+"""
+
+import unittest
+import sys
+from subprocess import check_call
+from vunit import ROOT
+
+
+class TestMyPy(unittest.TestCase):
+    """
+    Run MyPy static type analysis
+    """
+
+    @staticmethod
+    def test_pycodestyle():
+        check_call([sys.executable, "-m", "mypy", "vunit"])

tox.ini

@@ -11,6 +11,7 @@ deps=
     pytest
     lint: pycodestyle
     lint: pylint
+    lint: mypy
     docs: docutils
     docs: sphinx
     docs: sphinx-argparse

vunit/color_printer.py

@@ -15,9 +15,9 @@
 from vunit.ostools import IS_WINDOWS_SYSTEM
 
 
-class LinuxColorPrinter(object):
+class ColorPrinter(object):
     """
-    Print in color on linux
+    Base class
     """
 
     BLUE = "b"
@@ -29,6 +29,45 @@ class LinuxColorPrinter(object):
     def __init__(self):
         pass
 
+    @staticmethod
+    def write(
+        text, output_file=None, fg=None, bg=None
+    ):  # pylint: disable=unused-argument
+        """
+        Print the text in color to the output_file
+        uses stdout if output_file is None
+        """
+
+
+class NoColorPrinter(ColorPrinter):
+    """
+    Dummy printer that does not print in color
+    """
+
+    def __init__(self):
+        ColorPrinter.__init__(self)
+
+    @staticmethod
+    def write(
+        text, output_file=None, fg=None, bg=None
+    ):  # pylint: disable=unused-argument
+        """
+        Print the text in color to the output_file
+        uses stdout if output_file is None
+        """
+        if output_file is None:
+            output_file = sys.stdout
+        output_file.write(text)
+
+
+class LinuxColorPrinter(ColorPrinter):
+    """
+    Print in color on linux
+    """
+
+    def __init__(self):
+        ColorPrinter.__init__(self)
+
     def write(self, text, output_file=None, fg=None, bg=None):
         """
         Print the text in color to the output_file
@@ -110,13 +149,13 @@ class ConsoleScreenBufferInfo(Structure):
     ]
 
 
-class Win32ColorPrinter(LinuxColorPrinter):
+class Win32ColorPrinter(ColorPrinter):
     """
     Prints in color on windows
     """
 
     def __init__(self):
-        LinuxColorPrinter.__init__(self)
+        ColorPrinter.__init__(self)
         self._stdout_handle = ctypes.windll.kernel32.GetStdHandle(-11)
         self._stderr_handle = ctypes.windll.kernel32.GetStdHandle(-12)
         self._default_attr = self._get_text_attr(self._stdout_handle)
@@ -186,32 +225,13 @@ def _decode_color(self, color_str):
         return code
 
 
-class NoColorPrinter(object):
-    """
-    Dummy printer that does not print in color
-    """
-
-    def __init__(self):
-        pass
-
-    @staticmethod
-    def write(
-        text, output_file=None, fg=None, bg=None
-    ):  # pylint: disable=unused-argument
-        """
-        Print the text in color to the output_file
-        uses stdout if output_file is None
-        """
-        if output_file is None:
-            output_file = sys.stdout
-        output_file.write(text)
-
-
-NO_COLOR_PRINTER = NoColorPrinter()
+NO_COLOR_PRINTER: ColorPrinter = NoColorPrinter()
 
 # On MSYS/MINGW shells (https://www.msys2.org/) with Python installed through pacman, IS_WINDOWS_SYSTEM is true.
 # However, regular Linux color strings are supported/required, instead of 'native' windows color format.
 # Environment variable MSYSTEM is checked, which should contain 'msys'|'mingw32'|'mingw64' or be unset/empty.
+COLOR_PRINTER: ColorPrinter
+
 if IS_WINDOWS_SYSTEM and ("MSYSTEM" not in os.environ):
     COLOR_PRINTER = Win32ColorPrinter()
 else:

vunit/parsing/tokenizer.py

@@ -19,7 +19,11 @@ def Token(kind, value="", location=None):  # pylint: disable=invalid-name
     return TokenType(kind, value, location)
 
 
-def new_token_kind(name):
+class TokenKind:
+    pass
+
+
+def new_token_kind(name: str) -> TokenKind:
     """
     Create a new token kind with nice __repr__
     """

vunit/parsing/verilog/tokens.py

@@ -8,7 +8,8 @@
 Verilog tokens
 """
 
-from vunit.parsing.tokenizer import new_token_kind
+from typing import Dict
+from vunit.parsing.tokenizer import new_token_kind, TokenKind
 
 
 def __token(kind):
@@ -27,7 +28,7 @@ def __keyword(kind):
     return token_kind
 
 
-KEYWORDS = {}
+KEYWORDS: Dict[str, TokenKind] = {}
 
 PREPROCESSOR = __token("preprocessor")
 STRING = __token("string")

vunit/sim_if/__init__.py

@@ -11,21 +11,38 @@
 import sys
 import os
 import subprocess
+from typing import List
 from ..ostools import Process, simplify_path
 from ..exceptions import CompileError
 from ..color_printer import NO_COLOR_PRINTER
 
 
+class Option(object):
+    """
+    A compile or sim option
+    """
+
+    def __init__(self, name):
+        self._name = name
+
+    @property
+    def name(self):
+        return self._name
+
+    def validate(self, value):
+        pass
+
+
 class SimulatorInterface(object):  # pylint: disable=too-many-public-methods
     """
     Generic simulator interface
     """
 
-    name = None
+    name: str = "none"
     supports_gui_flag = False
     package_users_depend_on_bodies = False
-    compile_options = []
-    sim_options = []
+    compile_options: List[Option] = []
+    sim_options: List[Option] = []
 
     # True if simulator supports ANSI colors in GUI mode
     supports_colors_in_gui = False
@@ -347,22 +364,6 @@ def check_output(command, env=None):
     return output.decode("utf-8")
 
 
-class Option(object):
-    """
-    A compile or sim option
-    """
-
-    def __init__(self, name):
-        self._name = name
-
-    @property
-    def name(self):
-        return self._name
-
-    def validate(self, value):
-        pass
-
-
 class BooleanOption(Option):
     """
     Must be a boolean

vunit/test/runner.py

@@ -464,7 +464,9 @@ def wrap(file_obj, use_color=True):
     NOTE:
     imports colorama here to avoid dependency from setup.py importing VUnit before colorama is installed
     """
-    from colorama import AnsiToWin32  # pylint: disable=import-outside-toplevel
+    from colorama import (  # type: ignore # pylint: disable=import-outside-toplevel
+        AnsiToWin32,
+    )
 
     if use_color:
         return AnsiToWin32(file_obj).stream