SCANPY-180 The scanner should not publish non-error logs to stderr

Author: ghislainpiot

src/pysonar_scanner/app_logging.py

@@ -18,10 +18,34 @@
 # Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 #
 import logging
+import sys
+
+
+class LevelFilter(logging.Filter):
+    def __init__(self, level):
+        super().__init__()
+        self.__level = level
+
+    def filter(self, record):
+        return record.levelno < self.__level
 
 
 def setup() -> None:
-    logging.basicConfig(level=logging.INFO, format="%(levelname)s: %(message)s")
+    logger = logging.getLogger()
+
+    non_error_handler = logging.StreamHandler(sys.stdout)
+    non_error_handler.setLevel(logging.DEBUG)
+    non_error_handler.addFilter(LevelFilter(logging.ERROR))
+
+    error_handler = logging.StreamHandler(sys.stderr)
+    error_handler.setLevel(logging.ERROR)
+
+    formatter = logging.Formatter("%(levelname)s: %(message)s")
+    non_error_handler.setFormatter(formatter)
+    error_handler.setFormatter(formatter)
+
+    logger.addHandler(non_error_handler)
+    logger.addHandler(error_handler)
 
 
 def configure_logging_level(verbose: bool) -> None:

tests/unit/test_app_logging.py

@@ -0,0 +1,25 @@
+import logging
+import unittest
+
+import pytest
+
+from pysonar_scanner import app_logging
+
+
+class TestAppLogging(unittest.TestCase):
+    @pytest.fixture(autouse=True)
+    def set_capsys(self, capsys):
+        self.capsys = capsys
+
+    def setUp(self) -> None:
+        app_logging.setup()
+
+    def test_logging_output_destinations(self):
+        logging.info("hello world")
+        logging.error("boom!")
+
+        captured = self.capsys.readouterr()
+        self.assertIn("INFO: hello world", captured.out)
+        self.assertIn("ERROR: boom!", captured.err)
+        self.assertEqual(len(captured.err.splitlines()), 1)
+        self.assertEqual(len(captured.out.splitlines()), 1)