test(examples): introduce tests for examples

tests/test_examples.py

+import os
+from glob import glob
+from itertools import chain
+from typing import Callable, Generator
+
+import pytest
+
+from lp_nn_robustness_verification.examples.solve_instances_in_parallel import (
+    solve_and_store_timed_solutions,
+)
+from lp_nn_robustness_verification.examples.solve_one_instance import optimize
+
+
+@pytest.fixture(scope="module")
+def file_deleter() -> Callable[[tuple[str, ...]], None]:
+    def deleter(endings: tuple[str, ...]) -> None:
+        for file in chain(
+            *(glob(f"*{ending}") for ending in endings)
+        ):
+            try:
+                os.remove(file)
+            except FileNotFoundError:
+                pass
+
+    return deleter
+
+
+@pytest.fixture
+def cleanup_txt_sol_and_cip_after_run(
+    file_deleter: Callable[[tuple[str, ...]], None]
+) -> Generator[None, None, None]:
+    yield
+    file_deleter(("*_timings.txt", ".sol", ".cip"))
+
+
+@pytest.fixture
+def cleanup_txt_after_run(
+    file_deleter: Callable[[tuple[str, ...]], None]
+) -> Generator[None, None, None]:
+    yield
+    file_deleter(("*_timings.txt",))
+
+
+def test_solve_and_store_timed_solutions(
+    cleanup_txt_sol_and_cip_after_run: Generator[None, None, None]
+) -> None:
+    solve_and_store_timed_solutions(0, 0)
+
+
+def test_optimize(cleanup_txt_after_run: Generator[None, None, None]) -> None:
+    optimize()