feat: add held-out Qwen3.8 experiment protocol (#185)

tests/test_experiment_protocol.py

@@ -0,0 +1,53 @@
+from __future__ import annotations
+
+import json
+
+import pytest
+
+from obliteratus.experiment_protocol import build_qwen38_split
+
+
+def _corpus(size: int = 842) -> tuple[list[str], list[str]]:
+    return (
+        [f"harmful-{index}" for index in range(size)],
+        [f"harmless-{index}" for index in range(size)],
+    )
+
+
+def test_qwen38_split_is_exact_disjoint_and_reproducible():
+    harmful, harmless = _corpus()
+    first = build_qwen38_split(harmful, harmless)
+    second = build_qwen38_split(list(harmful), list(harmless))
+
+    assert [len(first.train), len(first.tune), len(first.test)] == [500, 142, 200]
+    assert first.manifest == second.manifest
+    identities = first.manifest["pair_ids"]
+    train = set(identities["train"])
+    tune = set(identities["tune"])
+    test = set(identities["test"])
+    assert not train & tune
+    assert not train & test
+    assert not tune & test
+    assert len(train | tune | test) == 842
+
+
+def test_qwen38_split_manifest_contains_no_prompt_text():
+    harmful, harmless = _corpus()
+    split = build_qwen38_split(harmful, harmless)
+    serialized = json.dumps(split.manifest)
+
+    assert "harmful-0" not in serialized
+    assert "harmless-0" not in serialized
+    assert len(split.manifest["manifest_sha256"]) == 64
+
+
+def test_qwen38_split_rejects_wrong_size_and_duplicate_pairs():
+    harmful, harmless = _corpus(4)
+    with pytest.raises(ValueError, match="split sizes total"):
+        build_qwen38_split(harmful, harmless)
+
+    harmful, harmless = _corpus()
+    harmful[1] = harmful[0]
+    harmless[1] = harmless[0]
+    with pytest.raises(ValueError, match="duplicate prompt pair"):
+        build_qwen38_split(harmful, harmless)