Convert MIPSolveStats into dataclass

tests/components/test_objective.py

@@ -255,5 +255,5 @@ def test_usage() -> None:
     solver.solve(instance)
     solver.fit([instance])
     stats = solver.solve(instance)
-    assert stats["Lower bound"] == stats["Objective: Predicted lower bound"]
-    assert stats["Upper bound"] == stats["Objective: Predicted upper bound"]
+    assert stats["mip_lower_bound"] == stats["Objective: Predicted lower bound"]
+    assert stats["mip_upper_bound"] == stats["Objective: Predicted upper bound"]

tests/components/test_primal.py

@@ -221,7 +221,7 @@ def test_usage() -> None:
     stats = solver.solve(instance)
     assert stats["Primal: Free"] == 0
     assert stats["Primal: One"] + stats["Primal: Zero"] == 10
-    assert stats["Lower bound"] == stats["Warm start value"]
+    assert stats["mip_lower_bound"] == stats["mip_warm_start_value"]
 
 
 def test_evaluate() -> None:

tests/problems/test_stab.py

@@ -16,7 +16,7 @@ def test_stab() -> None:
     instance = MaxWeightStableSetInstance(graph, weights)
     solver = LearningSolver()
     stats = solver.solve(instance)
-    assert stats["Lower bound"] == 2.0
+    assert stats["mip_lower_bound"] == 2.0
 
 
 def test_stab_generator_fixed_graph() -> None:

tests/problems/test_tsp.py

@@ -47,8 +47,8 @@ def test_instance() -> None:
     assert solution["x[(1, 2)]"] == 1.0
     assert solution["x[(1, 3)]"] == 0.0
     assert solution["x[(2, 3)]"] == 1.0
-    assert stats["Lower bound"] == 4.0
-    assert stats["Upper bound"] == 4.0
+    assert stats["mip_lower_bound"] == 4.0
+    assert stats["mip_upper_bound"] == 4.0
 
 
 def test_subtour() -> None:

tests/solvers/test_learning_solver.py

@@ -140,7 +140,7 @@ def test_simulate_perfect() -> None:
             simulate_perfect=True,
         )
         stats = solver.solve(PickleGzInstance(tmp.name))
-        assert stats["Lower bound"] == stats["Objective: Predicted lower bound"]
+        assert stats["mip_lower_bound"] == stats["Objective: Predicted lower bound"]
 
 
 def test_gap() -> None: