[drake_cmake_external] Add test case to disable solver

drake_cmake_external/CMakeLists.txt

@@ -112,6 +112,7 @@ ExternalProject_Add(drake
     -DWITH_USER_EIGEN:BOOLEAN=ON
     -DWITH_USER_FMT:BOOLEAN=ON
     -DWITH_USER_SPDLOG:BOOLEAN=ON
+    -DWITH_CSDP:BOOLEAN=OFF
   PREFIX "${DRAKE_PREFIX}"
   BINARY_DIR "${PROJECT_BINARY_DIR}/drake"
   BUILD_ALWAYS ON

drake_cmake_external/drake_external_examples/CMakeLists.txt

@@ -27,3 +27,13 @@ set_tests_properties(import_all_test PROPERTIES
   ENVIRONMENT "PYTHONPATH=${DRAKE_PYTHONPATH}"
 )
 
+add_test(NAME solver_disabled_test
+  COMMAND Python3::Interpreter -B -m unittest solver_disabled_test
+)
+set_tests_properties(solver_disabled_test PROPERTIES
+  ENVIRONMENT "PYTHONPATH=${DRAKE_PYTHONPATH}"
+  LABELS small
+  REQUIRED_FILES "${CMAKE_CURRENT_SOURCE_DIR}/solver_disabled_test.py"
+  TIMEOUT 60
+  WORKING_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}"
+)

drake_cmake_external/drake_external_examples/solver_disabled_test.py

@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: MIT-0
+
+"""
+Provides an example of disabling the open-source CSDP solver.
+"""
+
+import unittest
+
+from pydrake.solvers import CsdpSolver
+
+class TestCsdpSolver(unittest.TestCase):
+    def test_unavailable(self):
+        solver = CsdpSolver()
+        self.assertFalse(solver.available())
+
+if __name__ == '__main__':
+    unittest.main()