From 5d425f2ded9d4063d1c3cfd2f11537a8460a9c03 Mon Sep 17 00:00:00 2001
From: Taka <taka@vm-linux-dev>
Date: Fri, 18 Mar 2022 19:26:11 +1100
Subject: [PATCH] Allow logging to a file during tests.

---
 conftest.py                          | 20 ++++++++++++++++++--
 vasl_templates/webapp/tests/utils.py |  9 +++++++++
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/conftest.py b/conftest.py
index ddde4b1..aaa0dea 100644
--- a/conftest.py
+++ b/conftest.py
@@ -100,7 +100,7 @@ def _make_webapp():
     if webapp_url and not webapp_url.startswith( "http://" ):
         webapp_url = "http://" + webapp_url
     app.base_url = webapp_url if webapp_url else "http://localhost:{}".format( FLASK_WEBAPP_PORT )
-    logging.disable( logging.CRITICAL )
+    _disable_console_logging()
 
     # initialize
     # WTF?! https://github.com/pallets/flask/issues/824
@@ -191,7 +191,7 @@ def _make_webapp():
 @pytest.fixture( scope="session" )
 def test_client():
     """Return a test client that can be used to connect to the webapp."""
-    logging.disable( logging.CRITICAL )
+    _disable_console_logging()
     return app.test_client()
 
 # - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -232,3 +232,19 @@ def webdriver( request ):
         yield driver
     finally:
         driver.quit()
+
+# ---------------------------------------------------------------------
+
+def _disable_console_logging():
+    """Disable Python logging to the console.
+
+    We do this when running tests because:
+    (1) pytest's output is voluminous enough without including our stuff in there as well (and it tends to be
+        not that helpful, anyway)
+    (2) pytest captures all output and shows it when the test ends i.e. we don't get to see messages in real-time.
+    """
+    for logger in utils.get_all_loggers():
+        # NOTE: FileHandler derives from StreamHandler, and we want to keep those, so we can't use isinstance().
+        handlers = [ h for h in logger.handlers if type( h ) is logging.StreamHandler ] #pylint: disable=unidiomatic-typecheck
+        for h in handlers:
+            logger.removeHandler( h )
diff --git a/vasl_templates/webapp/tests/utils.py b/vasl_templates/webapp/tests/utils.py
index e4fb219..f504068 100644
--- a/vasl_templates/webapp/tests/utils.py
+++ b/vasl_templates/webapp/tests/utils.py
@@ -7,6 +7,7 @@ import time
 import re
 import typing
 import uuid
+import logging
 from collections import defaultdict
 
 import lxml.html
@@ -646,3 +647,11 @@ def get_css_classes( elem ):
     """Get the CSS classes for the specified element."""
     classes = elem.get_attribute( "class" )
     return classes.split() if classes else []
+
+# ---------------------------------------------------------------------
+
+def get_all_loggers():
+    """Return all Python loggers."""
+    yield logging.getLogger() # nb: this is the root logger
+    for name in logging.root.manager.loggerDict: #pylint: disable=no-member
+        yield logging.getLogger( name )