tests: use os.devnull instead of '/dev/null' for Windows CI

Author: rhysd

tests/test_cli.py

@@ -85,7 +85,7 @@ def test_cli_run_with_args_fd(capfd):
 def test_cli_run_subprocess_exception(runner, mocker):
     result = runner.invoke(cli.run, [os.devnull])
     out = result.output.splitlines()
-    assert out[-1].startswith("Error: Failed to run ['/dev/null', '--cmd',")
+    assert out[-1].startswith("Error: Failed to run ['%s', '--cmd'," % os.devnull)
     assert '[Errno 13] Permission denied' in out[-1]
     assert result.exit_code == 1
 
@@ -136,7 +136,7 @@ def test_cli_run_args(runner, mocker, devnull, tmpdir):
     assert m.call_args[0] == (['printf', '--', '--headless'],)
     assert result.output.splitlines() == [
         'Running cmd: printf -- --headless (in %s)' % os.getcwd(),
-        'Parsing profile file /dev/null.',
+        'Parsing profile file %s.' % os.devnull,
         'Not writing coverage file: no data to report!',
         'Error: Command exited non-zero: 3.']
 
@@ -329,7 +329,7 @@ def test_cli_call_verbosity_fd(capfd):
     out, err = capfd.readouterr()
     assert out == ''
     assert err.splitlines() == [
-        'Parsing file: /dev/null',
+        'Parsing file: %s' % os.devnull,
         'source_files: []',
         'Not writing coverage file: no data to report!',
         'Error: No data to report.']
@@ -338,7 +338,7 @@ def test_cli_call_verbosity_fd(capfd):
     out, err = capfd.readouterr()
     assert out == ''
     assert err.splitlines() == [
-        'Parsing file: /dev/null',
+        'Parsing file: %s' % os.devnull,
         'source_files: []',
         'Not writing coverage file: no data to report!',
         'Error: No data to report.']
@@ -490,7 +490,7 @@ def test_report_profile_or_data_file(runner, tmpdir):
         'report', '--data-file', os.devnull])
     cov_exc = 'CoverageException: Doesn\'t seem to be a coverage.py data file'
     assert result.output.splitlines()[-1] == \
-        'Error: Coverage could not read data_file: /dev/null (%s)' % cov_exc
+        'Error: Coverage could not read data_file: %s (%s)' % (os.devnull, cov_exc)
     assert result.exit_code == 1
 
     with tmpdir.as_cwd():

tests/test_coveragepy.py

@@ -1,3 +1,4 @@
+import os
 import sys
 
 import attr
@@ -165,7 +166,7 @@ def test_coveragewrapper(coverage_fileobj, devnull):
     with pytest.raises(CoverageWrapperException) as excinfo:
         CoverageWrapper(data_file=devnull.name)
     assert excinfo.value.args == (
-        'Coverage could not read data_file: /dev/null',)
+        'Coverage could not read data_file: %s' % os.devnull,)
 
     f = StringIO()
     with pytest.raises(CoverageWrapperException) as excinfo:

tests/test_main.py

@@ -1,4 +1,5 @@
 import logging
+import os
 import textwrap
 
 import coverage
@@ -39,7 +40,7 @@ def test_profile_fname_or_fobj(caplog, devnull):
     with caplog.at_level(logging.DEBUG, logger='covimerage'):
         Profile(devnull).parse()
     msgs = [(r.levelname, r.message) for r in caplog.records]
-    assert msgs == [('DEBUG', 'Parsing file: /dev/null')]
+    assert msgs == [('DEBUG', 'Parsing file: %s' % os.devnull)]
 
     fileobj = StringIO('')
     with caplog.at_level(logging.DEBUG, logger='covimerage'):

tests/test_utils.py

@@ -1,3 +1,5 @@
+import os
+
 from covimerage._compat import StringIO
 
 
@@ -27,7 +29,7 @@ def test_get_fname_and_fobj_and_str(devnull):
     F = get_fname_and_fobj_and_str
     assert F('foo') == ('foo', None, 'foo')
     assert F(None) == (None, None, 'None')
-    assert F(devnull) == ('/dev/null', devnull, '/dev/null')
+    assert F(devnull) == (os.devnull, devnull, os.devnull)
     s = StringIO('')
     assert F(s) == (None, s, str(s))