Merge d6e7ca6 into 7af287c

src/quantuminspire/api.py

@@ -26,7 +26,7 @@
 from coreapi.exceptions import CoreAPIException, ErrorMessage
 
 from quantuminspire.credentials import load_account
-from quantuminspire.exceptions import ApiError
+from quantuminspire.exceptions import ApiError, AuthenticationError
 from quantuminspire.job import QuantumInspireJob
 
 QI_URL = 'https://api.quantum-inspire.com'
@@ -61,7 +61,7 @@ def __init__(self, base_uri: str = QI_URL, authentication: Optional[coreapi.auth
             authentication: The authentication, can be one of the following coreapi authentications:
                             BasicAuthentication(email, password), HTTP authentication with valid email/password.
                             TokenAuthentication(token, scheme="token"), token authentication with a valid API-token.
-                            When authentication is None, a token is read from the default resource.
+                            When authentication is None, a token is read from the default location.
             project_name: The project used for executing the jobs.
             coreapi_client_class: Coreapi client to interact with the API through a schema.
                                   Default set to coreapi.Client.
@@ -72,15 +72,16 @@ def __init__(self, base_uri: str = QI_URL, authentication: Optional[coreapi.auth
               project name is supplied here.
 
         Raises:
-            ApiError: An ApiError exception is raised when no authentication is given and the token could not be
-                      loaded or the schema could not be loaded.
+            AuthenticationError: An AuthenticationError exception is raised when no authentication is given
+                                 and the token could not be loaded from the default location.
+            ApiError: An ApiError exception is raised when the schema could not be loaded.
         """
         if authentication is None:
             token = load_account()
             if token is not None:
                 authentication = TokenAuthentication(token, scheme="token")
             else:
-                raise ApiError('No credentials have been provided or found on disk')
+                raise AuthenticationError('No credentials have been provided or found on disk')
         self.__client = coreapi_client_class(auth=authentication)
         self.project_name = project_name
         self.base_uri = base_uri

src/quantuminspire/exceptions.py

@@ -25,5 +25,9 @@ class ProjectQBackendError(Exception):
     """ Exception for SDK errors related to the projectq backend."""
 
 
+class AuthenticationError(Exception):
+    """ Exception for SDK errors related to authentication."""
+
+
 class ApiError(Exception):
     """ Exception for SDK errors related to the API functionality."""

src/quantuminspire/projectq/backend_qx.py

@@ -30,6 +30,7 @@
                           Measure, Ph, Rx, Ry, Rz, S, Sdag, Swap, T, Tdag, X,
                           Y, Z, Command)
 from projectq.types import Qubit
+from quantuminspire.exceptions import AuthenticationError
 from quantuminspire.api import QuantumInspireAPI
 from quantuminspire.exceptions import ProjectQBackendError
 
@@ -47,7 +48,7 @@ def __init__(self, num_runs: int = 1024, verbose: int = 0, quantum_inspire_api:
         Args:
             num_runs: Number of runs to collect statistics (default is 1024).
             verbose: Verbosity level, defaults to 0, which produces no extra output.
-            quantum_inspire_api: Connection to QI platform, required parameter.
+            quantum_inspire_api: Connection to QI platform, optional parameter.
             backend_type: Backend to use for execution. When no backend_type is provided, the default backend will be
                           used.
         """
@@ -63,8 +64,12 @@ def __init__(self, num_runs: int = 1024, verbose: int = 0, quantum_inspire_api:
         self._measured_ids: List[int] = []
         self._allocated_qubits: Set[int] = set()
         self._max_qubit_id: int = -1
-        if not quantum_inspire_api:
-            raise RuntimeError("Api is required")
+        if quantum_inspire_api is None:
+            try:
+                quantum_inspire_api = QuantumInspireAPI()
+            except AuthenticationError as ex:
+                raise AuthenticationError('Make sure you have saved your token credentials on disk or '
+                                          'provide a QuantumInspireAPI instance as parameter to QIBackend') from ex
         self.quantum_inspire_api: QuantumInspireAPI = quantum_inspire_api
         self.backend_type: Optional[Union[Dict[str, Any], int, str]] = backend_type
 

src/tests/quantuminspire/projectq/test_backend_qx.py

@@ -18,6 +18,9 @@
 import io
 import unittest
 import warnings
+import json
+import os
+import coreapi
 from collections import OrderedDict
 from unittest.mock import MagicMock, patch
 
@@ -27,7 +30,7 @@
                           Ph, Rx, Ry, Rz, S, Sdag, Swap, T, Tdag, Toffoli, X,
                           Y, Z)
 
-from quantuminspire.exceptions import ProjectQBackendError
+from quantuminspire.exceptions import ProjectQBackendError, AuthenticationError
 from quantuminspire.projectq.backend_qx import QIBackend
 
 
@@ -51,9 +54,23 @@ def test_init_has_correct_values(self):
         self.assertEqual(backend.quantum_inspire_api, api)
         self.assertIsNone(backend.backend_type)
 
-    def test_init_raises_runtime_error(self):
-        api = None
-        self.assertRaises(RuntimeError, QIBackend, quantum_inspire_api=api)
+    def test_init_without_api_has_correct_values(self):
+        os.environ.get = MagicMock()
+        os.environ.get.return_value = 'token'
+        coreapi.Client.get = MagicMock()
+        backend = QIBackend()
+        self.assertIsInstance(backend.qasm, str)
+        self.assertNotEqual(backend.quantum_inspire_api, None)
+        self.assertIsNone(backend.backend_type)
+
+    def test_init_raises_no_account_authentication_error(self):
+        json.load = MagicMock()
+        json.load.return_value = {'faulty_key': 'faulty_token'}
+        os.environ.get = MagicMock()
+        os.environ.get.return_value = None
+        self.assertRaisesRegex(AuthenticationError, 'Make sure you have saved your token credentials on disk '
+                                                    'or provide a QuantumInspireAPI instance as parameter to QIBackend',
+                               QIBackend)
 
     def test_cqasm_returns_correct_cqasm_data(self):
         api = MockApiClient()

src/tests/quantuminspire/test_api.py

@@ -25,7 +25,7 @@
 from unittest.mock import Mock, patch, call, MagicMock, mock_open
 
 from quantuminspire.api import QuantumInspireAPI
-from quantuminspire.exceptions import ApiError
+from quantuminspire.exceptions import ApiError, AuthenticationError
 from quantuminspire.job import QuantumInspireJob
 
 
@@ -109,7 +109,7 @@ def test_no_authentication(self):
             api = QuantumInspireAPI(base_url, coreapi_client_class=self.coreapi_client)
             self.assertEqual(expected, api.document)
 
-    def test_no_authentication_raises_api_error(self):
+    def test_no_authentication_raises_authentication_error(self):
         expected_token = 'secret'
         json.load = MagicMock()
         json.load.return_value = {'wrong_key': expected_token}
@@ -120,7 +120,7 @@ def test_no_authentication_raises_api_error(self):
         url = ''.join([base_url, expected])
         self.coreapi_client.getters[url] = expected
         with patch("builtins.open", mock_open(read_data="secret_token")) as mock_file:
-            self.assertRaisesRegex(ApiError, 'No credentials have been provided', QuantumInspireAPI,
+            self.assertRaisesRegex(AuthenticationError, 'No credentials have been provided', QuantumInspireAPI,
                                    base_url, coreapi_client_class=self.coreapi_client)
 
     def test_load_schema_collects_correct_schema(self):