Merge pull request #2964 from nicolossus/port_issue_311

Port `issue-311` from SLI-2-Py

Author: heplesser

testsuite/pytests/sli2py_regressions/test_issue_311.py

@@ -0,0 +1,61 @@
+# -*- coding: utf-8 -*-
+#
+# test_issue_311.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/>.
+
+"""
+Regression test for Issue #311 (GitHub).
+
+This test ensures that NEST behaves properly when a model triggers an exception
+during update.
+"""
+
+import nest
+import pytest
+
+
+def test_nest_behaves_well_after_exception_during_update():
+    # Pathological parameters to trigger numerical exception
+    nrn = nest.Create("aeif_cond_alpha", params={"I_e": 10000000.0, "g_L": 0.01})
+
+    # Execute in try-except context so exception does not propagate out
+    did_crash = False
+    try:
+        nest.Simulate(100.0)
+    except nest.kernel.NESTErrors.NumericalInstability:
+        did_crash = True
+        pass
+
+    # did_crash must be true, otherwise no exception was triggered
+    assert did_crash
+
+    # Test that we still can inspect the kernel after an exception
+    nest.GetKernelStatus()
+
+    # Test that we cannot continue simulation after an exception.
+    # Set neuron parameters to values that should stabilize numerics
+    nrn.set({"V_m": -70.0, "w": 0.0, "I_e": 0.0})
+
+    with pytest.raises(nest.kernel.NESTErrors.KernelException):
+        nest.Simulate(0.1)
+
+    # Test that we can simulate again after a ResetKernel
+    nest.ResetKernel()
+    nest.Create("aeif_cond_alpha", params={"I_e": 1000.0})
+    nest.Simulate(100.0)