Nose to pytest transition (#183)

* Use mock from the standard lib if available.

* Migrate nose raises to pytest.raises.

This touches a lot of code because pytest.raises
is used in a context manager, so indentation
has to be changed.

Replacement happened with regex from
@raises\((.*)\) to @pytest.mark.xfail(raises=$1)
then from @pytest.mark.xfail\(raises=(.*)\)\ndef(.*)
to def$2\n    with pytest.raises($1):
then manual correction of indentation.

* Replace nose eq_ by assert, remove nottest.

* Move CI from nosetests to pytest, adapt docs.

Pin astroid version, too, to avoid wrong errors on CI.

* Fix some introduced errors flagged by pylint.

* Specify minimum pyserial requirement (see #58).

.gitignore

@@ -41,6 +41,7 @@ pip-log.txt
 .coverage
 .tox
 nosetests.xml
+.pytest_cache
 
 #Translations
 *.mo

.travis.yml

@@ -10,19 +10,20 @@ install:
   - "pip install -r dev-requirements.txt"
   - pip install python-coveralls
   - pip install coverage
+  - pip install pytest-cov
 before_script:
   # We use before_script to report version and path information in a way
   # that can be easily hidden by Travis' log folding. Moreover, a nonzero
   # exit code from this block kills the entire job, meaning that if we can't
   # even sensibly get version information, we correctly abort.
   - which python
   - python --version
-  - which nosetests
-  - nosetests --version
+  - which pytest
+  - pytest --version
   - which pylint
   - pylint --version
 script:
-  - nosetests --with-coverage -w instruments
+  - pytest --cov=instruments
   - pylint --py3k instruments
   - pylint --disable=I instruments
 after_success:

dev-requirements.txt

@@ -1,4 +1,5 @@
 mock
-nose
+pytest
 hypothesis
 pylint==1.7.1
+astroid==1.5.3

doc/source/devguide/index.rst

@@ -9,7 +9,7 @@ InstrumentKit Development Guide
     code_style
     testing
     util_fns
-    
+
 Introduction
 ============
 
@@ -34,7 +34,7 @@ provided ``dev-requirements.txt``::
 $ pip install -r dev-requirements.txt
 
 - mock
-- nose
+- pytest
 - pylint
 
 Optional Development Dependencies

doc/source/devguide/testing.rst

@@ -20,13 +20,13 @@ of InstrumentKit will not, in general, have access to each instrument that
 is supported--- we rely on automated testing to ensure that future changes
 do not cause invalid or undesired operation.
 
-For InstrumentKit, we rely heavily on `nose`_, a mature and flexible
+For InstrumentKit, we rely heavily on `pytest`_, a mature and flexible
 unit-testing framework for Python. When run from the command line via
-``nosetests``, or when run by Travis CI, nose will automatically execute
+``pytest``, or when run by Travis CI, pytest will automatically execute
 functions and methods whose names start with ``test`` in packages, modules
 and classes whose names start with ``test`` or ``Test``, depending. (Please
-see the `nose`_ documentation for full details, as this is not intended
-to be a guide to nose so much as a guide to how we use it in IK.)
+see the `pytest`_ documentation for full details, as this is not intended
+to be a guide to pytest so much as a guide to how we use it in IK.)
 Because of this, we keep all test cases in the ``instruments.tests``
 package, under a subpackage named for the particular manufacturer,
 such as ``instruments.tests.test_srs``. The tests for each instrument should
@@ -88,4 +88,4 @@ Protocol Assertion Functions
 
 .. autofunction:: expected_protocol
 
-.. _nose: https://nose.readthedocs.org/en/latest/
+.. _pytest: https://docs.pytest.org/en/latest/

instruments/tests/__init__.py

@@ -17,7 +17,10 @@
 
 from builtins import bytes, str
 
-from nose.tools import nottest, eq_
+try:
+    from unittest import mock  # from Python 3.3 onward, this is in the stdlib
+except ImportError:
+    import mock
 
 # FUNCTIONS ##################################################################
 
@@ -90,7 +93,6 @@ def expected_protocol(ins_class, host_to_ins, ins_to_host, sep="\n"):
     #     """Only read {} bytes out of {}""".format(current, end)
 
 
-@nottest
 def unit_eq(a, b, msg=None, thresh=1e-5):
     """
     Asserts that two unitful quantites ``a`` and ``b``
@@ -103,13 +105,12 @@ def unit_eq(a, b, msg=None, thresh=1e-5):
     assert a.units == b.units, "{} and {} have different units".format(a, b)
 
 
-@nottest
 def make_name_test(ins_class, name_cmd="*IDN?"):
     """
     Given an instrument class, produces a test which asserts that the instrument
     correctly reports its name in response to a standard command.
     """
     def test():
         with expected_protocol(ins_class, name_cmd + "\n", "NAME\n") as ins:
-            eq_(ins.name, "NAME")
+            assert ins.name == "NAME"
     return test