Remove noise_specs from local-emulator backends (#572)

Author: cqc-alec

docs/changelog.md

@@ -4,6 +4,10 @@
 
 # Changelog
 
+## Unreleased
+
+- Remove `noise_specs` from local-emulator backends.
+
 ## 0.43.0 (January 2025)
 
 - Check for language support when submitting programs.

pytket/extensions/quantinuum/__init__.py

@@ -12,8 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""Backends for processing pytket circuits with Quantinuum devices
-"""
+"""Backends for processing pytket circuits with Quantinuum devices"""
 
 # _metadata.py is copied to the folder after installation.
 from ._metadata import (

pytket/extensions/quantinuum/backends/__init__.py

@@ -12,8 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""Backends for processing pytket circuits with Quantinuum devices
-"""
+"""Backends for processing pytket circuits with Quantinuum devices"""
 
 from .api_wrappers import (
     QuantinuumAPI as QuantinuumAPI,

pytket/extensions/quantinuum/backends/quantinuum.py

@@ -390,6 +390,7 @@ def _dict_to_backendinfo(
             dct1["system_type"] = "local_emulator"
             dct1.pop("emulator", None)
             dct1["batching"] = False
+            dct1.pop("noise_specs", None)
         return BackendInfo(
             name=cls.__name__,
             device_name=name + "LE" if local_emulator else name,

tests/integration/local_emulator_test.py

@@ -479,3 +479,21 @@ def test_result_handling_for_empty_bits(
         n_shots=1,
     )
     assert result.get_counts() == {(0, 0): 1}
+
+
+@pytest.mark.skipif(skip_remote_tests, reason=REASON)
+@pytest.mark.skipif(not have_pecos(), reason="pecos not installed")
+@pytest.mark.parametrize(
+    "authenticated_quum_backend_prod",
+    [{"device_name": name} for name in pytest.ALL_LOCAL_SIMULATOR_NAMES],  # type: ignore
+    indirect=True,
+)
+def test_no_noise(
+    authenticated_quum_backend_prod: QuantinuumBackend,
+) -> None:
+    # https://github.com/CQCL/pytket-quantinuum/issues/571
+
+    backend = authenticated_quum_backend_prod
+    backend_info = backend.backend_info
+    assert backend_info is not None
+    assert "noise_specs" not in backend_info.misc