Add some InternalSolver tests to main package

miplearn/solvers/tests/__init__.py

@@ -0,0 +1,81 @@
+#  MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization
+#  Copyright (C) 2020-2021, UChicago Argonne, LLC. All rights reserved.
+#  Released under the modified BSD license. See COPYING.md for more details.
+
+from miplearn.solvers.internal import InternalSolver
+from miplearn.instance.base import Instance
+from typing import Any
+
+
+def assert_equals(left: Any, right: Any) -> None:
+    assert left == right, f"{left} != {right}"
+
+
+def test_internal_solver(
+    solver: InternalSolver,
+    instance: Instance,
+    model: Any,
+) -> None:
+    solver.set_instance(instance, model)
+
+    assert_equals(
+        solver.get_variable_names(),
+        ["x[0]", "x[1]", "x[2]", "x[3]"],
+    )
+
+    lp_stats = solver.solve_lp()
+    assert not solver.is_infeasible()
+    assert lp_stats["LP value"] is not None
+    assert_equals(round(lp_stats["LP value"], 3), 1287.923)
+    assert len(lp_stats["LP log"]) > 100
+
+    solution = solver.get_solution()
+    assert solution is not None
+    assert solution["x[0]"] is not None
+    assert solution["x[1]"] is not None
+    assert solution["x[2]"] is not None
+    assert solution["x[3]"] is not None
+    assert_equals(round(solution["x[0]"], 3), 1.000)
+    assert_equals(round(solution["x[1]"], 3), 0.923)
+    assert_equals(round(solution["x[2]"], 3), 1.000)
+    assert_equals(round(solution["x[3]"], 3), 0.000)
+
+    mip_stats = solver.solve(
+        tee=True,
+        iteration_cb=None,
+        lazy_cb=None,
+        user_cut_cb=None,
+    )
+    assert not solver.is_infeasible()
+    assert len(mip_stats["MIP log"]) > 100
+    assert_equals(mip_stats["Lower bound"], 1183.0)
+    assert_equals(mip_stats["Upper bound"], 1183.0)
+    assert_equals(mip_stats["Sense"], "max")
+    assert isinstance(mip_stats["Wallclock time"], float)
+
+    solution = solver.get_solution()
+    assert solution is not None
+    assert solution["x[0]"] is not None
+    assert solution["x[1]"] is not None
+    assert solution["x[2]"] is not None
+    assert solution["x[3]"] is not None
+    assert_equals(solution["x[0]"], 1.0)
+    assert_equals(solution["x[1]"], 0.0)
+    assert_equals(solution["x[2]"], 1.0)
+    assert_equals(solution["x[3]"], 1.0)
+
+    assert_equals(solver.get_constraint_ids(), ["eq_capacity"])
+    assert_equals(
+        solver.get_constraint_rhs("eq_capacity"),
+        67.0,
+    )
+    assert_equals(
+        solver.get_constraint_lhs("eq_capacity"),
+        {
+            "x[0]": 23.0,
+            "x[1]": 26.0,
+            "x[2]": 20.0,
+            "x[3]": 18.0,
+        },
+    )
+    assert_equals(solver.get_constraint_sense("eq_capacity"), "<")