Fix resource warnings thanks to PDM (#68)

* Run Azure tests in python development mode
* Fix identified resource leaks

Author: Anthchirp

HISTORY.rst

@@ -5,6 +5,7 @@ History
 2.3.0 (????-??-??)
 ------------------
 * Python 3.6+ only, support for Python 3.5 has been dropped
+* Fix a file descriptor leak on subprocess execution
 
 2.2.0 (2020-09-07)
 ------------------

procrunner/__init__.py

@@ -132,6 +132,7 @@ def _thread_write_stream_to_buffer():
                 else:
                     if self._closing:
                         break
+            self._stream.close()
             self._terminated = True
             la.flush()
             if self._debug:
@@ -151,6 +152,7 @@ def _thread_write_stream_to_buffer_windows():
                             print(linedecode)
                         if callback:
                             callback(linedecode)
+            self._stream.close()
             self._terminated = True
             if self._debug:
                 logger.debug("Stream reader terminated")

tests/test_procrunner_system.py

@@ -56,7 +56,9 @@ def test_running_wget(tmp_path):
 def test_path_object_resolution(tmp_path):
     sentinel_value = b"sentinel"
     tmp_path.joinpath("tempfile").write_bytes(sentinel_value)
-    tmp_path.joinpath("reader.py").write_text("print(open('tempfile').read())")
+    tmp_path.joinpath("reader.py").write_text(
+        "with open('tempfile') as fh:\n    print(fh.read())"
+    )
     assert "LEAK_DETECTOR" not in os.environ
     result = procrunner.run(
         [sys.executable, tmp_path / "reader.py"],

tox.ini

@@ -14,6 +14,8 @@ deps =
     pytest-azurepipelines
     pytest-cov
     -r{toxinidir}/requirements_dev.txt
+setenv =
+    PYTHONDEVMODE = 1
 commands =
     pytest -ra --basetemp={envtmpdir} --cov=procrunner --cov-report=html --cov-report=xml --cov-branch