Port test_delay_exchange from SLI to Py

testsuite/pytests/mpi/4/test_delay_exchange.py

@@ -0,0 +1,43 @@
+# -*- coding: utf-8 -*-
+#
+# test_delay_exchange.py
+#
+# This file is part of NEST.
+#
+# Copyright (C) 2004 The NEST Initiative
+#
+# NEST is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#
+# NEST is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with NEST.  If not, see <http://www.gnu.org/licenses/>.
+
+import nest
+
+
+def test_delay_exchange():
+    """
+    Confirm that creating a single connection on a single rank will set delay extrema on all ranks.
+
+    @note This test must be run on multiple MPI ranks to be meaningful.
+    """
+
+    assert nest.num_processes == 4
+
+    min_delay = 0.5
+    max_delay = 2.5
+
+    n = nest.Create("parrot_neuron")
+    nest.Connect(n, n, "one_to_one", {"synapse_model": "static_synapse", "delay": min_delay})
+    nest.Connect(n, n, "one_to_one", {"synapse_model": "static_synapse", "delay": max_delay})
+
+    # Accessing kernel attributes forces GetKernelStatus with exchange of delay info
+    assert nest.min_delay == min_delay
+    assert nest.max_delay == max_delay