bpo-42644: Validate values in logging.disable() (GH-23786)

* bpo-42644: Validate values in logging.disable()

Technically make the value of manager a property that checks and convert
values assigned to it properly. This has the side effect of making
`logging.disable` also accept strings representing the various level of
warnings.

We want to validate the type of the disable attribute at assignment
time, as it is later compared to other levels when emitting warnings and
would generate a `TypeError: '>=' not supported between ....` in a
different part of the code base, which can make it difficult to track
down.

When assigned an incorrect value; it will raise a TypeError when the
wrong type, or ValueError if an invalid str.

Co-authored-by: Andrew Svetlov <andrew.svetlov@gmail.com>
(cherry picked from commit b32d8b4f9bcd2e7d11240b6b9de0262cf8f5e09d)

Co-authored-by: Matthias Bussonnier <bussonniermatthias@gmail.com>

3 files changed, 20 insertions, 0 deletions

diff --git a/Lib/logging/__init__.py b/Lib/logging/__init__.py
index 7b169a1..6920a7b 100644
--- a/Lib/logging/__init__.py
+++ b/Lib/logging/__init__.py
@@ -1269,6 +1269,14 @@ class Manager(object):
         self.loggerClass = None
         self.logRecordFactory = None
 
+    @property
+    def disable(self):
+        return self._disable
+
+    @disable.setter
+    def disable(self, value):
+        self._disable = _checkLevel(value)
+
     def getLogger(self, name):
         """
         Get a logger with the specified name (channel name), creating it
diff --git a/Lib/test/test_logging.py b/Lib/test/test_logging.py
index 410eae2..a6cd291 100644
--- a/Lib/test/test_logging.py
+++ b/Lib/test/test_logging.py
@@ -4191,6 +4191,15 @@ class ModuleLevelMiscTest(BaseTest):
         logging.disable(83)
         self.assertEqual(logging.root.manager.disable, 83)
 
+        self.assertRaises(ValueError, logging.disable, "doesnotexists")
+
+        class _NotAnIntOrString:
+            pass
+
+        self.assertRaises(TypeError, logging.disable, _NotAnIntOrString())
+
+        logging.disable("WARN")
+
         # test the default value introduced in 3.7
         # (Issue #28524)
         logging.disable()
diff --git a/Misc/NEWS.d/next/Library/2020-12-15-10-00-04.bpo-42644.XgLCNx.rst b/Misc/NEWS.d/next/Library/2020-12-15-10-00-04.bpo-42644.XgLCNx.rst
new file mode 100644
index 0000000..f58b58e
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-12-15-10-00-04.bpo-42644.XgLCNx.rst
@@ -0,0 +1,3 @@
+`logging.disable` will now validate the types and value of its parameter. It
+also now accepts strings representing the levels (as does `loging.setLevel`)
+instead of only the numerical values.