Providerv1 deprication patch

qiskit_braket_provider/providers/braket_provider.py

@@ -6,12 +6,12 @@
 from braket.device_schema.dwave import DwaveDeviceCapabilities
 from braket.device_schema.quera import QueraDeviceCapabilities
 from braket.device_schema.xanadu import XanaduDeviceCapabilities
-from qiskit.providers import ProviderV1
+from qiskit.providers.exceptions import QiskitBackendNotFoundError
 
 from .braket_backend import BraketAwsBackend, BraketLocalBackend
 
 
-class BraketProvider(ProviderV1):
+class BraketProvider:
     """BraketProvider class for accessing Amazon Braket backends.
 
     Example:
@@ -29,7 +29,36 @@ class BraketProvider(ProviderV1):
          BraketBackend[dm1]]
     """
 
+    def get_backend(self, name=None, **kwargs):
+        """Return a single backend matching the specififed filters.
+
+        Args:
+            name (str): name of the selected backend
+            **kwargs: dict with additional options for filitering and storing aws session
+        Returns:
+            BraketAwsBackend: a backend matching the filters.
+        Raises:
+            QiskitBackendNotFoundError: if no backend could be found or
+            more than one backend matches the filters.
+        """
+        backends = self.backends(name=name, **kwargs)
+        if len(backends) > 1:
+            raise QiskitBackendNotFoundError(
+                "More than one backend matches the criteria"
+            )
+        if not backends:
+            raise QiskitBackendNotFoundError("No backend matches the criteria")
+        return backends[0]
+
     def backends(self, name=None, **kwargs):
+        """Return a list of backends matching the specififed filters.
+
+        Args:
+            name (str): name of the selected backend
+            **kwargs: dict with additional options for filitering and storing aws session
+        Returns:
+            BraketAwsBackend: a list of backends matching the filters.
+        """
         if kwargs.get("local"):
             return [
                 BraketLocalBackend(name="braket_sv"),

tests/providers/test_braket_provider.py

@@ -10,6 +10,7 @@
 from qiskit import QuantumCircuit
 from qiskit import circuit as qiskit_circuit
 from qiskit.compiler import transpile
+from qiskit.providers.exceptions import QiskitBackendNotFoundError
 
 from qiskit_braket_provider.providers import BraketProvider
 from qiskit_braket_provider.providers.braket_backend import (
@@ -38,6 +39,30 @@ def setUp(self):
         self.mock_session.boto_session.region_name = SIMULATOR_REGION
         self.mock_session.search_devices.return_value = simulators
 
+        self.empty_mock_session = Mock()
+        self.empty_mock_session.get_device.side_effect = []
+        self.empty_mock_session.region = SIMULATOR_REGION
+        self.empty_mock_session.boto_session.region_name = SIMULATOR_REGION
+        self.empty_mock_session.search_devices.return_value = []
+
+    def test_provider_backend(self):
+        """Test QiskitBackendNotFoundError is raised"""
+        provider = BraketProvider()
+
+        # Matches QiskitBackendNotFoundError where multiple backends are found
+        with self.assertRaises(QiskitBackendNotFoundError) as err1:
+            provider.get_backend(
+                aws_session=self.mock_session, types=[AwsDeviceType.SIMULATOR]
+            )
+        self.assertIsInstance(err1.exception, QiskitBackendNotFoundError)
+
+        # Matches QiskitBackendNotFoundError where no backends are found
+        with self.assertRaises(QiskitBackendNotFoundError) as err2:
+            provider.get_backend(
+                aws_session=self.empty_mock_session, types=[AwsDeviceType.SIMULATOR]
+            )
+        self.assertIsInstance(err2.exception, QiskitBackendNotFoundError)
+
     def test_provider_backends(self):
         """Tests provider."""
         provider = BraketProvider()