Merge pull request #26 from nicoddemus/race-condition-on-collect

Race condition on collect

Author: nicoddemus

CHANGELOG.md

@@ -1,3 +1,7 @@
+# 0.4.1 #
+
+- Fix error that may happen during collection when using xdist (#25).
+
 # 0.4.0 #
 
 - Integrated most of the examples found in boost-1.55 for Boost Test into the
@@ -32,4 +36,4 @@ it behave correctly if a test writes in `std::cout` or `std::cerr`.
 
 # 0.1.0 #
 
-Support for Google Test and Boost Test.
+Support for Google Test and Boost Test.

pytest_cpp/plugin.py

@@ -13,7 +13,11 @@
 
 
 def pytest_collect_file(parent, path):
-    is_executable = os.stat(str(path)).st_mode & stat.S_IXUSR
+    try:
+        is_executable = os.stat(str(path)).st_mode & stat.S_IXUSR
+    except OSError:
+        # in some situations the file might not be available anymore at this point
+        return False
     if not is_executable:
         return
     masks = parent.config.getini('cpp_files') or DEFAULT_MASKS

setup.py

@@ -3,7 +3,7 @@
 
 setup(
     name="pytest-cpp",
-    version='0.4',
+    version='0.4.1',
     packages=['pytest_cpp'],
     entry_points={
         'pytest11': ['cpp = pytest_cpp.plugin'],

tests/test_pytest_cpp.py

@@ -241,6 +241,22 @@ def test_passing_files_directly_in_command_line(testdir, exes):
     result.stdout.fnmatch_lines(['*1 passed*'])
 
 
+def test_race_condition_on_collect(tmpdir):
+    """
+    Check that collection correctly handles when a path no longer is valid.
+
+    This might happen in some situations when xdist is collecting multiple files, and that
+    causes temporary .pyc files to be generated; in those situations, pytest may obtain that
+    filename and ask plugins if they can collect it, but by the time a plugin is called
+    the file may be gone already:
+
+    OSError: [Errno 2] No such file or directory:
+        '/../test_duplicate_filenames.cpython-27-PYTEST.pyc.21746'
+    """
+    import pytest_cpp.plugin
+    assert not pytest_cpp.plugin.pytest_collect_file(None, tmpdir / 'invalid-file')
+
+
 class TestError:
 
     def test_get_whitespace(self):