Checkpoint experiments through SWE pilot v2

tests/test_seed_files.py

@@ -0,0 +1,20 @@
+import pytest
+
+from messageboardbench.task import validate_seed_files
+
+
+@pytest.mark.parametrize("name", ["../escape.py", "/tmp/file", "a/b", ".", "..", "", "a\\b"])
+def test_seeds_cannot_escape_scratch(name):
+    with pytest.raises(ValueError):
+        validate_seed_files({name: "content"})
+
+
+def test_seed_is_copied_without_changing_content():
+    files = {"reference.py": "# agent-written\ndef f(): return 3\n"}
+    assert validate_seed_files(files) == files
+    assert validate_seed_files(files) is not files
+
+
+def test_byte_limit_handles_multibyte_text():
+    with pytest.raises(ValueError):
+        validate_seed_files({"reference.py": "é" * 40000})