Checkpoint experiments through SWE pilot v2

tests/test_communication_plan.py

@@ -0,0 +1,38 @@
+from copy import deepcopy
+
+import pytest
+
+from messageboardbench.communication_plan import (
+    build_communication_plan,
+    verify_communication_plan,
+)
+
+
+def binding():
+    return {
+        "teams": 3,
+        "model": "openrouter/example/model",
+        "schedule": [{"team": 1, "cohort": 1, "condition": "sham"}],
+    }
+
+
+def test_plan_binds_configuration_and_analysis() -> None:
+    frozen = build_communication_plan(binding())
+    verify_communication_plan(frozen, binding())
+    assert frozen["analysis"]["unit_of_assignment_and_inference"].startswith("independent")
+    assert frozen["analysis"]["estimand"].startswith("intention-to-treat")
+    assert frozen["analysis"]["primary_label_workflow"]["primary_labels_frozen_before_unblinding"]
+    assert frozen["failure_handling"]["sample_retries"] == 0
+
+
+def test_plan_rejects_too_few_teams_tampering_and_config_drift() -> None:
+    with pytest.raises(ValueError, match="at least two"):
+        build_communication_plan({"teams": 1})
+    frozen = build_communication_plan(binding())
+    tampered = deepcopy(frozen)
+    tampered["analysis"]["point_estimator"] = "changed after freezing"
+    with pytest.raises(ValueError, match="self-hash"):
+        verify_communication_plan(tampered, binding())
+    changed = {**binding(), "model": "openrouter/other/model"}
+    with pytest.raises(ValueError, match="configuration"):
+        verify_communication_plan(frozen, changed)