add test for EasyConfig comparison & hashing + add __ne__ definition

easybuild/framework/easyconfig/easyconfig.py

@@ -722,10 +722,16 @@ def get(self, key, default=None):
         else:
             return default
 
+    # *both* __eq__ and __ne__ must be implemented for == and != comparisons to work correctly
+    # see also https://docs.python.org/2/reference/datamodel.html#object.__eq__
     def __eq__(self, ec):
         """Is this EasyConfig instance equivalent to the provided one?"""
         return self.asdict() == ec.asdict()
 
+    def __ne__(self, ec):
+        """Is this EasyConfig instance equivalent to the provided one?"""
+        return self.asdict() != ec.asdict()
+
     def __hash__(self):
         """Return hash value for a hashable representation of this EasyConfig instance."""
         def make_hashable(val):
@@ -736,11 +742,12 @@ def make_hashable(val):
                 val = tuple([(key, make_hashable(val)) for (key, val) in sorted(val.items())])
             return val
 
-        tup = ()
+        lst = []
         for (key, val) in sorted(self.asdict().items()):
-            tup += (key, make_hashable(val))
+            lst.append((key, make_hashable(val)))
 
-        return hash(tup)
+        # a list is not hashable, but a tuple is
+        return hash(tuple(lst))
 
     def asdict(self):
         """

test/framework/easyconfig.py

@@ -1535,6 +1535,26 @@ def test_param_value_type_checking(self):
         error_msg_pattern = "Type checking of easyconfig parameter values failed: .*'name'.*'version'.*"
         self.assertErrorRegex(EasyBuildError, error_msg_pattern, EasyConfig, ec_file)
 
+    def test_eq_hash(self):
+        """Test comparing two EasyConfig instances."""
+        test_easyconfigs = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'easyconfigs')
+        ec1 = EasyConfig(os.path.join(test_easyconfigs, 'toy-0.0.eb'))
+        ec2 = EasyConfig(os.path.join(test_easyconfigs, 'toy-0.0.eb'))
+
+        # different instances, same parsed easyconfig
+        self.assertFalse(ec1 is ec2)
+        self.assertEqual(ec1, ec2)
+        self.assertTrue(ec1 == ec2)
+        self.assertFalse(ec1 != ec2)
+
+        # hashes should also be identical
+        self.assertEqual(hash(ec1), hash(ec2))
+
+        # other parsed easyconfig is not equal
+        ec3 = EasyConfig(os.path.join(test_easyconfigs, 'gzip-1.4.eb'))
+        self.assertFalse(ec1 == ec3)
+        self.assertTrue(ec1 != ec3)
+
 
 def suite():
     """ returns all the testcases in this module """