Move instance fixtures into the main source; remove duplication

tests/solvers/__init__.py

@@ -1,33 +0,0 @@
-#  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 inspect import isclass
-from typing import Any
-
-from miplearn.instance.base import Instance
-from miplearn.problems.knapsack import KnapsackInstance, GurobiKnapsackInstance
-from miplearn.solvers.gurobi import GurobiSolver
-from miplearn.solvers.pyomo.base import BasePyomoSolver
-
-
-def _is_subclass_or_instance(obj: Any, parent_class: Any) -> bool:
-    return isinstance(obj, parent_class) or (
-        isclass(obj) and issubclass(obj, parent_class)
-    )
-
-
-def _get_knapsack_instance(solver: Any) -> Instance:
-    if _is_subclass_or_instance(solver, BasePyomoSolver):
-        return KnapsackInstance(
-            weights=[23.0, 26.0, 20.0, 18.0],
-            prices=[505.0, 352.0, 458.0, 220.0],
-            capacity=67.0,
-        )
-    if _is_subclass_or_instance(solver, GurobiSolver):
-        return GurobiKnapsackInstance(
-            weights=[23.0, 26.0, 20.0, 18.0],
-            prices=[505.0, 352.0, 458.0, 220.0],
-            capacity=67.0,
-        )
-    assert False

tests/solvers/test_internal_solver.py

@@ -13,11 +13,9 @@ from miplearn import InternalSolver
 from miplearn.solvers import _RedirectOutput
 from miplearn.solvers.gurobi import GurobiSolver
 from miplearn.solvers.pyomo.base import BasePyomoSolver
-from . import _get_knapsack_instance
 
 # noinspection PyUnresolvedReferences
 from .. import internal_solvers
-from ..fixtures.infeasible import get_infeasible_instance
 
 logger = logging.getLogger(__name__)
 
@@ -38,7 +36,7 @@ def test_internal_solver_warm_starts(
 ) -> None:
     for solver in internal_solvers:
         logger.info("Solver: %s" % solver)
-        instance = _get_knapsack_instance(solver)
+        instance = solver.build_test_instance_knapsack()
         model = instance.to_model()
         solver.set_instance(instance, model)
         solver.set_warm_start({"x[0]": 1.0, "x[1]": 0.0, "x[2]": 0.0, "x[3]": 1.0})
@@ -64,7 +62,7 @@ def test_internal_solver(
     for solver in internal_solvers:
         logger.info("Solver: %s" % solver)
 
-        instance = _get_knapsack_instance(solver)
+        instance = solver.build_test_instance_knapsack()
         model = instance.to_model()
         solver.set_instance(instance, model)
 
@@ -169,7 +167,7 @@ def test_relax(
     internal_solvers: List[InternalSolver],
 ) -> None:
     for solver in internal_solvers:
-        instance = _get_knapsack_instance(solver)
+        instance = solver.build_test_instance_knapsack()
         solver.set_instance(instance)
         solver.relax()
         stats = solver.solve()
@@ -181,7 +179,7 @@ def test_infeasible_instance(
     internal_solvers: List[InternalSolver],
 ) -> None:
     for solver in internal_solvers:
-        instance = get_infeasible_instance(solver)
+        instance = solver.build_test_instance_infeasible()
         solver.set_instance(instance)
         mip_stats = solver.solve()
 
@@ -200,7 +198,7 @@ def test_iteration_cb(
 ) -> None:
     for solver in internal_solvers:
         logger.info("Solver: %s" % solver)
-        instance = _get_knapsack_instance(solver)
+        instance = solver.build_test_instance_knapsack()
         solver.set_instance(instance)
         count = 0
 

tests/solvers/test_lazy_cb.py

@@ -7,14 +7,13 @@ from typing import Any
 
 from miplearn import InternalSolver
 from miplearn.solvers.gurobi import GurobiSolver
-from . import _get_knapsack_instance
 
 logger = logging.getLogger(__name__)
 
 
 def test_lazy_cb() -> None:
     solver = GurobiSolver()
-    instance = _get_knapsack_instance(solver)
+    instance = solver.build_test_instance_knapsack()
     model = instance.to_model()
 
     def lazy_cb(cb_solver: InternalSolver, cb_model: Any) -> None:

tests/solvers/test_learning_solver.py

@@ -13,7 +13,6 @@ from miplearn import Instance, InternalSolver
 from miplearn.instance.picklegz import PickleGzInstance, write_pickle_gz, read_pickle_gz
 from miplearn.solvers.gurobi import GurobiSolver
 from miplearn.solvers.learning import LearningSolver
-from . import _get_knapsack_instance
 
 # noinspection PyUnresolvedReferences
 from tests import internal_solvers
@@ -27,7 +26,7 @@ def test_learning_solver(
     for mode in ["exact", "heuristic"]:
         for internal_solver in internal_solvers:
             logger.info("Solver: %s" % internal_solver)
-            instance = _get_knapsack_instance(internal_solver)
+            instance = internal_solver.build_test_instance_knapsack()
             solver = LearningSolver(
                 solver=internal_solver,
                 mode=mode,
@@ -71,7 +70,7 @@ def test_solve_without_lp(
 ) -> None:
     for internal_solver in internal_solvers:
         logger.info("Solver: %s" % internal_solver)
-        instance = _get_knapsack_instance(internal_solver)
+        instance = internal_solver.build_test_instance_knapsack()
         solver = LearningSolver(
             solver=internal_solver,
             solve_lp=False,
@@ -85,7 +84,7 @@ def test_parallel_solve(
     internal_solvers: List[InternalSolver],
 ) -> None:
     for internal_solver in internal_solvers:
-        instances = [_get_knapsack_instance(internal_solver) for _ in range(10)]
+        instances = [internal_solver.build_test_instance_knapsack() for _ in range(10)]
         solver = LearningSolver(solver=internal_solver)
         results = solver.parallel_solve(instances, n_jobs=3)
         assert len(results) == 10
@@ -102,7 +101,7 @@ def test_solve_fit_from_disk(
         # Create instances and pickle them
         instances: List[Instance] = []
         for k in range(3):
-            instance = _get_knapsack_instance(internal_solver)
+            instance = internal_solver.build_test_instance_knapsack()
             with tempfile.NamedTemporaryFile(suffix=".pkl", delete=False) as file:
                 instances += [PickleGzInstance(file.name)]
                 write_pickle_gz(instance, file.name)
@@ -132,7 +131,7 @@ def test_solve_fit_from_disk(
 
 def test_simulate_perfect() -> None:
     internal_solver = GurobiSolver()
-    instance = _get_knapsack_instance(internal_solver)
+    instance = internal_solver.build_test_instance_knapsack()
     with tempfile.NamedTemporaryFile(suffix=".pkl", delete=False) as tmp:
         write_pickle_gz(instance, tmp.name)
         solver = LearningSolver(