add typing (except protocols) and update docstring to use Numpy-style

.github/workflows/ci.yml

@@ -30,7 +30,7 @@ jobs:
       - name: Install tools
         run: |
           python -m pip install --upgrade pip
-          pip install flake8 black isort
+          pip install flake8 black isort mypy
           pip install git+https://github.com/pyvisa/pyvisa.git#egg=pyvisa
       - name: Isort
         run: |
@@ -41,6 +41,9 @@ jobs:
       - name: Flake8
         run: |
           flake8 pyvisa-py;
+      - name: Mypy
+        run: |
+          mypy pyvisa;
   tests:
     name: Unit tests
     runs-on: ${{ matrix.os }}
@@ -86,5 +89,5 @@ jobs:
         if: needs.tests.result == 'success'
         run: exit 0
       - name: Mark the job as a failure
-        if: needs.tests.result == 'failure'
+        if: needs.tests.result != 'success'
         run: exit 1

pyvisa-py/common.py

@@ -1,40 +1,44 @@
 # -*- coding: utf-8 -*-
-"""
-    pyvisa-sim.common
-    ~~~~~~~~~~~~~~~~~
+"""Common code.
 
-    Common code.
+:copyright: 2014-2020 by PyVISA-sim Authors, see AUTHORS for more details.
+:license: MIT, see LICENSE for more details.
 
-    :copyright: 2014-2020 by PyVISA-sim Authors, see AUTHORS for more details.
-    :license: MIT, see LICENSE for more details.
 """
 import logging
+from typing import Optional, SupportsBytes
 
 from pyvisa import logger
 
 logger = logging.LoggerAdapter(logger, {"backend": "py"})
 
 
 class MockInterface(object):
-    def __init__(self, resource_name):
+
+    #: Name of the resource used to create this interface
+    resource_name: str
+
+    def __init__(self, resource_name) -> None:
         self.resource_name = resource_name
 
 
 class NamedObject(object):
-    """A class to construct named sentinels.
-    """
+    """A class to construct named sentinels."""
 
-    def __init__(self, name):
+    #: Name used to identify the sentinel
+    name: str
+
+    def __init__(self, name) -> None:
         self.name = name
 
-    def __repr__(self):
+    def __repr__(self) -> str:
         return "<%s>" % self.name
 
     __str__ = __repr__
 
 
-def iter_bytes(data, mask=None, send_end=False):
-
+# XXX can probably be removed
+def iter_bytes(data: SupportsBytes, mask: Optional[int] = None, send_end: bool = False):
     if send_end and mask is None:
         raise ValueError("send_end requires a valid mask.")