Handle scip limits in BranchingDynamics::step_transition. Finish fix #98

Author: AntoinePrv

libecole/src/dynamics/branching.cpp

@@ -50,7 +50,11 @@ auto BranchingDynamics::step_dynamics(scip::Model& model, std::size_t const& act
 	}
 	model.solve_iter_branch(SCIPcolGetVar(lp_cols[action]));
 
-	return {model.solve_iter_is_done(), action_set(model, pseudo_candidates)};
+	auto const done = model.solve_iter_is_done();
+	if (done) {
+		return {done, {}};
+	}
+	return {done, action_set(model, pseudo_candidates)};
 }
 
 }  // namespace ecole::dynamics

libecole/tests/src/dynamics/test-branching.cpp

@@ -25,7 +25,7 @@ TEST_CASE("BranchingDynamics unit tests", "[unit][dynamics]") {
 
 TEST_CASE("BranchingDynamics functional tests", "[dynamics]") {
 	bool const pseudo_candidates = GENERATE(true, false);
-	dynamics::BranchingDynamics dyn{pseudo_candidates};
+	auto dyn = dynamics::BranchingDynamics{pseudo_candidates};
 	auto model = get_model();
 
 	SECTION("Return valid action set") {
@@ -56,3 +56,25 @@ TEST_CASE("BranchingDynamics functional tests", "[dynamics]") {
 		REQUIRE_THROWS_AS(dyn.step_dynamics(model, action), std::exception);
 	}
 }
+
+TEST_CASE("BranchingDynamics handles limits", "[dynamics]") {
+	bool const pseudo_candidates = GENERATE(true, false);
+	auto dyn = dynamics::BranchingDynamics{pseudo_candidates};
+	auto model = get_model();
+
+	SECTION("Node limit") {
+		auto const node_limit = GENERATE(0, 1, 2);
+		model.set_param("limits/totalnodes", node_limit);
+	}
+
+	SECTION("Time limit") {
+		auto const time_limit = GENERATE(0, 1, 2);
+		model.set_param("limits/time", time_limit);
+	}
+
+	auto [done, action_set] = dyn.reset_dynamics(model);
+	while (!done) {
+		REQUIRE(action_set.has_value());
+		std::tie(done, action_set) = dyn.step_dynamics(model, action_set.value()[0]);
+	}
+}