Add some basic warnings configuration overrides for the common offenders. Should fix #694 and fix #693.

Author: ionelmc

src/pytest_cov/plugin.py

@@ -9,11 +9,13 @@
 
 import coverage
 import pytest
+from coverage.exceptions import CoverageWarning
 from coverage.results import display_covered
 from coverage.results import should_fail_under
 
 from . import CovDisabledWarning
 from . import CovReportWarning
+from . import PytestCovWarning
 from . import compat
 from . import embed
 
@@ -312,6 +314,11 @@ def _should_report(self):
     # runs, it's too late to set testsfailed
     @pytest.hookimpl(hookwrapper=True)
     def pytest_runtestloop(self, session):
+        # override some warning configuration to prevent certain warnings to bubble up as errors due to rigid filterwarnings configuration
+        warnings.filterwarnings('default', 'unclosed database in <sqlite3.Connection object at', ResourceWarning)
+        warnings.simplefilter('once', PytestCovWarning)
+        warnings.simplefilter('once', CoverageWarning)
+
         yield
 
         if self._disabled:

tests/test_pytest_cov.py

@@ -1348,8 +1348,6 @@ def test_filterwarnings_error(testdir):
     [pytest]
     filterwarnings =
         error
-        once::coverage.exceptions.CoverageWarning
-        once::pytest_cov.PytestCovWarning
     """)
     testdir.makepyfile(mod=MODULE)
     testdir.makepyfile(plug=CONFTEST)