Add skip statement to doctests; start ipopt unit tests

doc/OnlineDocs/developer_reference/solvers.rst

@@ -35,6 +35,7 @@ Backwards Compatible Mode
 ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 .. testcode::
+   :skipif: not ipopt_available
 
    import pyomo.environ as pyo
    from pyomo.contrib.solver.util import assert_optimal_termination
@@ -53,6 +54,7 @@ Backwards Compatible Mode
    model.pprint()
 
 .. testoutput::
+   :skipif: not ipopt_available
    :hide:
 
    2 Var Declarations
@@ -66,6 +68,7 @@ There are multiple ways to utilize the future capability mode: direct import
 or changed ``SolverFactory`` version.
 
 .. testcode::
+   :skipif: not ipopt_available
 
     # Direct import
    import pyomo.environ as pyo
@@ -89,6 +92,7 @@ or changed ``SolverFactory`` version.
    model.pprint()
 
 .. testoutput::
+   :skipif: not ipopt_available
    :hide:
 
    solution_loader: ...
@@ -98,6 +102,7 @@ or changed ``SolverFactory`` version.
 Changing the ``SolverFactory`` version:
 
 .. testcode::
+   :skipif: not ipopt_available
 
     # Change SolverFactory version
    import pyomo.environ as pyo
@@ -120,13 +125,15 @@ Changing the ``SolverFactory`` version:
    model.pprint()
 
 .. testoutput::
+   :skipif: not ipopt_available
    :hide:
 
    solution_loader: ...
    ...
    3 Declarations: x y obj
 
 .. testcode::
+   :skipif: not ipopt_available
    :hide:
 
    from pyomo.__future__ import solver_factory_v1

pyomo/contrib/solver/tests/unit/test_ipopt.py

@@ -0,0 +1,73 @@
+#  ___________________________________________________________________________
+#
+#  Pyomo: Python Optimization Modeling Objects
+#  Copyright (c) 2008-2024
+#  National Technology and Engineering Solutions of Sandia, LLC
+#  Under the terms of Contract DE-NA0003525 with National Technology and
+#  Engineering Solutions of Sandia, LLC, the U.S. Government retains certain
+#  rights in this software.
+#  This software is distributed under the 3-clause BSD License.
+#  ___________________________________________________________________________
+
+from pyomo.common import unittest, Executable
+from pyomo.repn.plugins.nl_writer import NLWriter
+from pyomo.contrib.solver import ipopt
+
+
+ipopt_available = ipopt.Ipopt().available()
+
+
+@unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
+class TestIpoptSolverConfig(unittest.TestCase):
+    def test_default_instantiation(self):
+        config = ipopt.IpoptConfig()
+        # Should be inherited
+        self.assertIsNone(config._description)
+        self.assertEqual(config._visibility, 0)
+        self.assertFalse(config.tee)
+        self.assertTrue(config.load_solutions)
+        self.assertTrue(config.raise_exception_on_nonoptimal_result)
+        self.assertFalse(config.symbolic_solver_labels)
+        self.assertIsNone(config.timer)
+        self.assertIsNone(config.threads)
+        self.assertIsNone(config.time_limit)
+        # Unique to this object
+        self.assertIsInstance(config.executable, type(Executable('path')))
+        self.assertIsInstance(config.writer_config, type(NLWriter.CONFIG()))
+
+    def test_custom_instantiation(self):
+        config = ipopt.IpoptConfig(description="A description")
+        config.tee = True
+        self.assertTrue(config.tee)
+        self.assertEqual(config._description, "A description")
+        self.assertFalse(config.time_limit)
+        # Default should be `ipopt`
+        self.assertIsNotNone(str(config.executable))
+        self.assertIn('ipopt', str(config.executable))
+        # Set to a totally bogus path
+        config.executable = Executable('/bogus/path')
+        self.assertIsNone(config.executable.executable)
+        self.assertFalse(config.executable.available())
+
+
+class TestIpoptResults(unittest.TestCase):
+    def test_default_instantiation(self):
+        res = ipopt.IpoptResults()
+        # Inherited methods/attributes
+        self.assertIsNone(res.solution_loader)
+        self.assertIsNone(res.incumbent_objective)
+        self.assertIsNone(res.objective_bound)
+        self.assertIsNone(res.solver_name)
+        self.assertIsNone(res.solver_version)
+        self.assertIsNone(res.iteration_count)
+        self.assertIsNone(res.timing_info.start_timestamp)
+        self.assertIsNone(res.timing_info.wall_time)
+        # Unique to this object
+        self.assertIsNone(res.timing_info.ipopt_excluding_nlp_functions)
+        self.assertIsNone(res.timing_info.nlp_function_evaluations)
+        self.assertIsNone(res.timing_info.total_seconds)
+
+
+@unittest.skipIf(not ipopt_available, "The 'ipopt' command is not available")
+class TestIpoptInterface(unittest.TestCase):
+    pass