GaudiKernel: migrate tests to pytest and various fixes

Migrate the GaudiKernel python tests from nose to pytest (they were already running as pytest but with several deprecation warnings).

In addition extend test_Configurables to cover more use-cases (in preparation for !1503 (merged)):

• Fix the cleanup function
• Extend the test to dict and list properties
• Migrate to pytest fixtures and exception handling

GaudiKernel/tests/nose/test_Configurables.py

 #####################################################################################
-# (c) Copyright 1998-2020 CERN for the benefit of the LHCb and ATLAS collaborations #
+# (c) Copyright 1998-2023 CERN for the benefit of the LHCb and ATLAS collaborations #
 #                                                                                   #
 # This software is distributed under the terms of the Apache version 2 licence,     #
 # copied verbatim in the file "LICENSE".                                            #
@@ -8,16 +8,19 @@
 # granted to it by virtue of its status as an Intergovernmental Organization        #
 # or submit itself to any jurisdiction.                                             #
 #####################################################################################
-# Prepare dummy configurables
+import pytest
 from GaudiKernel.Configurable import Configurable, ConfigurableAlgorithm
 from GaudiKernel.DataHandle import DataHandle
 
 
+# Prepare dummy configurables
 class MyAlg(ConfigurableAlgorithm):
     __slots__ = {
         "Text": "some text",
         "Int": 23,
         "DataHandle": DataHandle("Location", "R"),
+        "Dict": {},
+        "List": [],
     }
 
     def getDlls(self):
@@ -27,7 +30,10 @@ class MyAlg(ConfigurableAlgorithm):
         return "MyAlg"
 
 
-def _clean_confs():
+@pytest.fixture(autouse=True)
+def clean_confs():
+    """ensure that all tests start from a clean configuration"""
+    MyAlg.configurables.clear()
     Configurable.allConfigurables.clear()
 
 
@@ -41,10 +47,14 @@ def test_correct():
     a.Int = 42
     a.Text = "value"
     a.DataHandle = "/Event/X"
+    a.Dict = {"a": 1}
+    a.List = [1, 2]
     assert a.getValuedProperties() == {
         "Int": 42,
         "Text": "value",
         "DataHandle": DataHandle("/Event/X", "R"),
+        "Dict": {"a": 1},
+        "List": [1, 2],
     }
 
 
@@ -56,51 +66,34 @@ def test_str_from_datahandle():
 
 def test_invalid_value():
     a = MyAlg()
-    try:
+
+    with pytest.raises(ValueError):
         a.Int = "value"
-        assert False, "exception expected"
-    except AssertionError:
-        raise
-    except ValueError:
-        pass
-    except Exception as x:
-        assert False, "ValueError exception expected, got %s" % type(x).__name__
-
-    try:
+
+    with pytest.raises(ValueError):
         a.Text = [123]
-        assert False, "exception expected"
-    except AssertionError:
-        raise
-    except ValueError:
-        pass
-    except Exception as x:
-        assert False, "ValueError exception expected, got %s" % type(x).__name__
-
-    try:
+
+    with pytest.raises(ValueError):
         a.DataHandle = [123]
-        assert False, "exception expected"
-    except AssertionError:
-        raise
-    except ValueError:
-        pass
-    except Exception as x:
-        assert False, "ValueError exception expected, got %s" % type(x).__name__
+
+    with pytest.raises(ValueError):
+        a.Dict = []
+
+    with pytest.raises(ValueError):
+        a.List = {}
 
 
 def test_invalid_key():
     a = MyAlg()
-    try:
+
+    with pytest.raises(AttributeError):
         a.Dummy = "abc"
-        assert False, "exception expected"
-    except AssertionError:
-        raise
-    except AttributeError:
-        pass
-    except Exception as x:
-        assert False, "AttributeError exception expected, got %s" % type(x).__name__
-
-
-# ensure that all tests start from clean configuration
-for _f in dir():
-    if _f.startswith("test"):
-        setattr(locals()[_f], "setup", _clean_confs)
+
+
+def test_collection_defaults():
+    a = MyAlg()
+    assert a.Dict == {}
+    assert a.List == []
+
+    a.List += [1]
+    assert a.List == [1]