Inconsistent ordering of tags (#6123)

* added sorted(*) to fix issue of identical sets being labeled unequal and added tests

* only comparing description when given

* Update cirq-core/cirq/ops/gateset_test.py

Co-authored-by: Tanuj Khattar <tanujkhattar@google.com>

* ran formatter

---------

Co-authored-by: Tanuj Khattar <tanujkhattar@google.com>

cirq-core/cirq/ops/gateset.py

@@ -257,11 +257,12 @@ def __repr__(self) -> str:
 
     def _value_equality_values_(self) -> Any:
         # `isinstance` is used to ensure the a gate type and gate instance is not compared.
+        description = self.description if self.description != self._default_description() else None
         return (
             isinstance(self.gate, raw_types.Gate),
             self.gate,
             self.name,
-            self.description,
+            description,
             self._ignore_global_phase,
             self._tags_to_accept,
             self._tags_to_ignore,

cirq-core/cirq/ops/gateset_test.py

@@ -81,6 +81,27 @@ def test_gate_family_default_name_and_description(gate, tags_to_accept, tags_to_
     assert (ignored_match is None) == (tags_to_ignore == [])
 
 
+@pytest.mark.parametrize(
+    'tags_to_accept_fam1, tags_to_ignore_fam1, tags_to_accept_fam2, tags_to_ignore_fam2',
+    [
+        (tuple("ab"), tuple("cd"), tuple("ba"), tuple("dc")),
+        (tuple("ab"), [], tuple("ba"), []),
+        ([], tuple("ab"), [], tuple("ba")),
+    ],
+)
+def test_gate_family_equality_with_tags(
+    tags_to_accept_fam1, tags_to_ignore_fam1, tags_to_accept_fam2, tags_to_ignore_fam2
+):
+    gate_fam1 = cirq.GateFamily(
+        cirq.X, tags_to_accept=tags_to_accept_fam1, tags_to_ignore=tags_to_ignore_fam1
+    )
+    gate_fam2 = cirq.GateFamily(
+        cirq.X, tags_to_accept=tags_to_accept_fam2, tags_to_ignore=tags_to_ignore_fam2
+    )
+
+    assert gate_fam1 == gate_fam2
+
+
 def test_invalid_gate_family():
     with pytest.raises(ValueError, match='instance or subclass of `cirq.Gate`'):
         _ = cirq.GateFamily(gate=cirq.Operation)