[bugfix] Make attrs() utility function pass when an AttributeError is raised

reframe/utility/__init__.py

@@ -275,7 +275,9 @@ def repr(obj, htchar=' ', lfchar='\n', indent=4, basic_offset=0):
 def attrs(obj):
     '''Inspect object and return its attributes and their values.
 
-    This function returns also any descriptors found at the owner class.
+    This function returns also any descriptors found at the owner class,
+    with the exception of descriptors without an assigned value, which are
+    expected to raise an ``AttributeError``.
 
     :arg obj: The object to inspect.
     :returns: an iterator over ``(attr_name, value)`` tuples
@@ -287,9 +289,13 @@ def attrs(obj):
 
     # Look for descriptors
     for cls in type(obj).mro():
-        for attr, value in cls.__dict__.items():
-            if inspect.isdatadescriptor(value):
-                ret[attr] = getattr(obj, attr)
+        for attr in cls.__dict__:
+            if inspect.isdatadescriptor(cls.__dict__[attr]):
+                try:
+                    ret[attr] = getattr(obj, attr)
+                except AttributeError:
+                    # Pass if the descriptor does not have an assigned value
+                    pass
 
     return ret
 

unittests/test_utility.py

@@ -658,9 +658,14 @@ def test_repr_default():
 
 
 def test_attrs():
-    class C:
+    class B:
         z = fields.TypedField(int)
 
+        def __init__(self, x, y):
+            self.x = x
+            self.y = y
+
+    class C(B):
         def __init__(self, x, y):
             self._x = x
             self.y = y
@@ -676,6 +681,13 @@ def x(self):
     class D(C):
         pass
 
+    # Test undefined descriptors are not returned
+    b = B(-1, 0)
+    b_attrs = util.attrs(b)
+    assert b_attrs['x'] == -1
+    assert b_attrs['y'] == 0
+    assert 'z' not in b_attrs
+
     c = C(1, 2)
     c_attrs = util.attrs(c)
     assert c_attrs['x'] == 1