Fix for empty job properties

qiskit/providers/ibmq/job/ibmqjob.py

@@ -189,12 +189,21 @@ def qobj(self):
     def properties(self):
         """Return the backend properties for this job.
 
+        The properties might not be available if the job hasn't completed,
+        in which case None is returned.
+
         Returns:
-            BackendProperties: the backend properties used for this job.
+            BackendProperties: the backend properties used for this job, or None if
+                properties are not available.
         """
         self._wait_for_submission()
 
         properties = self._api.job_properties(job_id=self.job_id())
+
+        # Backend properties of a job might not be available if the job hasn't
+        # completed. This is to ensure the properties returned are up to date.
+        if not properties:
+            return None
         return BackendProperties.from_dict(properties)
 
     # pylint: disable=arguments-differ

test/ibmq/test_ibmq_job.py

@@ -407,6 +407,17 @@ def test_error_message_qasm(self, qe_token, qe_url):
         message = job_sim.error_message()
         self.assertIn('Job resulted in the following QASM status(es): ', message)
 
+    @slow_test
+    @requires_qe_access
+    def test_running_job_properties(self, qe_token, qe_url):
+        """Test fetching properties of a running job."""
+        IBMQ.enable_account(qe_token, qe_url)
+        backend = least_busy(IBMQ.backends(simulator=False))
+
+        qobj = assemble(transpile(self._qc, backend=backend), backend=backend)
+        job = backend.run(qobj)
+        _ = job.properties()
+
 
 def _bell_circuit():
     qr = QuantumRegister(2, 'q')