Add default provider options (#74)

* Specifically pass the hub, group and project to IBMQ.get_provider * Update documentation with provider options * Update docs with passing a provider explicitly * Add custom provider and default provider unit tests * Linting * Unit test for custom provider options * Changing to use plugin specific device creation, adding needed mocking of active_account * Whitespaces * Update README.rst Co-Authored-By: Nathan Killoran <[email protected]> * Update README.rst Co-Authored-By: Nathan Killoran <[email protected]> * Update README.rst Co-Authored-By: Nathan Killoran <[email protected]> * Update tests/test_ibmq.py Co-Authored-By: Nathan Killoran <[email protected]> Co-authored-by: Nathan Killoran <[email protected]>
PennyLaneAI · Mar 15, 2020 · 2b94058 · 2b94058
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diff --git a/README.rst b/README.rst
@@ -205,6 +205,29 @@ Note that, by default, the ``qiskit.ibmq`` device uses the simulator backend
 
     dev.capabilities()['backend']
 
+When getting a ``qiskit.ibmq`` device a Qiskit provider is used to connect to the IBM Q systems.
+
+Custom providers can be passed as arguments when a ``qiskit.ibmq`` device is created:
+
+.. code-block:: python
+
+    from qiskit import IBMQ
+    provider = IBMQ.enable_account('XYZ')
+
+    import pennylane as qml
+    dev = qml.device('qiskit.ibmq', wires=2, backend='ibmq_qasm_simulator', provider=provider)
+
+If no provider is passed explicitly, then the official provider is used, with options of ``hub='ibm-q'``, ``group='open'`` and ``project='main'``.
+
+Custom provider options can be passed as keyword arguments when creating a device:
+
+.. code-block:: python
+
+    import pennylane as qml
+    dev = qml.device('qiskit.ibmq', wires=2, backend='ibmq_qasm_simulator', ibmqx_token='XXX', hub='MYHUB', group='MYGROUP', project='MYPROJECT')
+
+More details on Qiskit providers can be found at the `IBMQ provider documentation <https://qiskit.org/documentation/apidoc/ibmq-provider.html>`_.
+
 .. gettingstarted-end-inclusion-marker-do-not-remove
 
 Please refer to the `plugin documentation <https://pennylane-qiskit.readthedocs.io/>`_ as

diff --git a/pennylane_qiskit/ibmq.py b/pennylane_qiskit/ibmq.py
@@ -33,7 +33,6 @@
 ~~~~~~~~~~~~
 """
 import os
-import warnings
 
 from qiskit import IBMQ
 from qiskit.providers.ibmq.exceptions import IBMQAccountError
@@ -75,6 +74,11 @@ def __init__(self, wires, provider=None, backend="ibmq_qasm_simulator", shots=10
         token = os.getenv("IBMQX_TOKEN") or kwargs.get("ibmqx_token", None)
         url = os.getenv("IBMQX_URL") or kwargs.get("ibmqx_url", None)
 
+        # Specify a single hub, group and project
+        hub = kwargs.get("hub", 'ibm-q')
+        group = kwargs.get("group", 'open')
+        project = kwargs.get("project", 'main')
+
         if token is not None:
             # token was provided by the user, so attempt to enable an
             # IBM Q account manually
@@ -101,6 +105,6 @@ def __init__(self, wires, provider=None, backend="ibmq_qasm_simulator", shots=10
         # IBM Q account is now enabled
 
         # get a provider
-        p = provider or IBMQ.get_provider()
+        p = provider or IBMQ.get_provider(hub=hub, group=group, project=project)
 
         super().__init__(wires=wires, provider=p, backend=backend, shots=shots, **kwargs)
diff --git a/tests/test_ibmq.py b/tests/test_ibmq.py
@@ -8,6 +8,8 @@
 from qiskit.providers.ibmq.exceptions import IBMQAccountError
 
 from pennylane_qiskit import IBMQDevice
+from pennylane_qiskit import ibmq as ibmq
+from pennylane_qiskit import qiskit_device as qiskit_device
 
 
 @pytest.fixture
@@ -36,6 +38,74 @@ def test_account_already_loaded(token):
     dev = IBMQDevice(wires=1)
     assert dev.provider.credentials.is_ibmq()
 
+class MockQiskitDeviceInit:
+    """A mocked version of the QiskitDevice __init__ method which
+    is called on by the IBMQDevice"""
+
+    def mocked_init(self, wires, provider, backend, shots, **kwargs):
+        """Stores the provider which QiskitDevice.__init__ was
+        called with."""
+        self.provider = provider
+
+def test_custom_provider(monkeypatch):
+    """Tests that a custom provider can be passed when creating an IBMQ
+    device."""
+    mock_provider = "MockProvider"
+    mock_qiskit_device = MockQiskitDeviceInit()
+
+    with monkeypatch.context() as m:
+        m.setattr(ibmq.QiskitDevice, "__init__",mock_qiskit_device.mocked_init)
+        m.setattr(ibmq.IBMQ, "enable_account", lambda *args, **kwargs: None)
+
+        # Here mocking to a value such that it is not None
+        m.setattr(ibmq.IBMQ, "active_account", lambda *args, **kwargs: True)
+        dev = IBMQDevice(wires=2, backend='ibmq_qasm_simulator', provider=mock_provider)
+
+    assert mock_qiskit_device.provider == mock_provider
+
+def mock_get_provider(*args, **kwargs):
+    """A mock function for the get_provider Qiskit function to record the
+    arguments which it was called with."""
+    return (args, kwargs)
+
+def test_default_provider(monkeypatch):
+    """Tests that the default provider is used when no custom provider was
+    specified."""
+    mock_qiskit_device = MockQiskitDeviceInit()
+
+    with monkeypatch.context() as m:
+        m.setattr(ibmq.QiskitDevice, "__init__", mock_qiskit_device.mocked_init)
+        m.setattr(ibmq.IBMQ, "get_provider", mock_get_provider)
+        m.setattr(ibmq.IBMQ, "enable_account", lambda *args, **kwargs: None)
+
+        # Here mocking to a value such that it is not None
+        m.setattr(ibmq.IBMQ, "active_account", lambda *args, **kwargs: True)
+        dev = IBMQDevice(wires=2, backend='ibmq_qasm_simulator')
+
+    assert mock_qiskit_device.provider[0] == ()
+    assert mock_qiskit_device.provider[1] == {'hub': 'ibm-q', 'group': 'open', 'project': 'main'}
+
+def test_custom_provider_hub_group_project(monkeypatch):
+    """Tests that the custom arguments passed during device instantiation are
+    used when calling get_provider."""
+    mock_qiskit_device = MockQiskitDeviceInit()
+
+    custom_hub = "SomeHub"
+    custom_group = "SomeGroup"
+    custom_project = "SomeProject"
+
+    with monkeypatch.context() as m:
+        m.setattr(ibmq.QiskitDevice, "__init__", mock_qiskit_device.mocked_init)
+        m.setattr(ibmq.IBMQ, "get_provider", mock_get_provider)
+        m.setattr(ibmq.IBMQ, "enable_account", lambda *args, **kwargs: None)
+
+        # Here mocking to a value such that it is not None
+        m.setattr(ibmq.IBMQ, "active_account", lambda *args, **kwargs: True)
+        dev = IBMQDevice(wires=2, backend='ibmq_qasm_simulator', hub=custom_hub, group=custom_group, project=custom_project)
+
+    assert mock_qiskit_device.provider[0] == ()
+    assert mock_qiskit_device.provider[1] == {'hub': custom_hub, 'group': custom_group, 'project': custom_project}
+
 
 def test_load_from_disk(token):
     IBMQ.save_account(token)