New test file for session in unit test

test/unit/test_session.py

@@ -0,0 +1,55 @@
+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2021.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+"""IBMBackend Test."""
+
+from qiskit import QuantumCircuit
+from qiskit.test.reference_circuits import ReferenceCircuits
+
+from qiskit_ibm_provider import IBMProvider
+from qiskit_ibm_provider.session import Session
+from qiskit_ibm_provider.exceptions import IBMInputValueError
+
+from ..ibm_test_case import IBMTestCase
+
+
+class TestSession(IBMTestCase):
+    """Test Session module."""
+
+    def test_provider_and_no_backend(self):
+        """Test missing backend."""
+        circ = ReferenceCircuits.bell()
+        backend = "ibmq_qasm_simulator"
+        session = Session()
+        provider = IBMProvider(session=session)
+        _ = provider.backends(name=backend)[0]
+        self.assertTrue(session.backend() is None)
+        self.assertEqual(provider._session, session)
+
+    def test_passing_ibm_backend(self):
+        """Test passing in IBMBackend instance."""
+        backend_name = "ibm_gotham"
+        session = Session(backend_name=backend_name)
+        self.assertEqual(session.backend(), "ibm_gotham")
+
+    def test_max_time(self):
+        """Test max time."""
+        max_times = [
+            (42, 42),
+            ("1h", 1 * 60 * 60),
+            ("2h 30m 40s", 2 * 60 * 60 + 30 * 60 + 40),
+            ("40s 1h", 40 + 1 * 60 * 60),
+        ]
+        for max_t, expected in max_times:
+            with self.subTest(max_time=max_t):
+                session = Session(backend_name="ibm_gotham", max_time=max_t)
+                self.assertEqual(session._max_time, expected)