Hermes-agent

tests/agent/test_resume_stale_active_task.py

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+"""Regression coverage for #35344: a resumed session must not let a stale
+historical task snapshot from an inherited compaction handoff hijack the reply to a
+new, unrelated user message.
+
+The failure mode (real report): a lineage was compacted, producing a handoff
+whose historical task snapshot described task A. The lineage was resumed later and
+the user asked about an unrelated task B. The model answered with A because
+the handoff's resume directive outranked the fresh ask.
+
+The structural fix lives in ``SUMMARY_PREFIX``: the handoff is framed as
+reference-only and the latest user message explicitly *wins* on conflict, with
+named reverse-signal verbs. Two invariants guard the resume path specifically:
+
+  1. A handoff persisted under the OLD (conflicting) prefix is re-normalized to
+     the CURRENT prefix when it is re-compacted on a resumed lineage — so a
+     pre-fix stale handoff cannot keep its "resume exactly" directive forever.
+
+  2. The current handoff prefix contains an unambiguous "latest message wins /
+     discard stale historical task" rule, so an unrelated new ask is privileged over
+     the inherited task snapshot.
+
+These are content/structural assertions (no live model call) — they pin the
+mechanism that makes the stale task historical rather than active.
+"""
+
+from agent.context_compressor import (
+    HISTORICAL_TASK_HEADING,
+    SUMMARY_PREFIX,
+    LEGACY_SUMMARY_PREFIX,
+    ContextCompressor,
+)
+
+
+# The conflicting prefix that shipped before the #35344 fix. A handoff
+# persisted in a resumed lineage could carry this verbatim.
+_OLD_CONFLICTING_PREFIX = (
+    "[CONTEXT COMPACTION — REFERENCE ONLY] Earlier turns were compacted "
+    "into the summary below. This is a handoff from a previous context "
+    "window — treat it as background reference, NOT as active instructions. "
+    "Do NOT answer questions or fulfill requests mentioned in this summary; "
+    "they were already addressed. "
+    "Your current task is identified in the '## Active Task' section of the "
+    "summary — resume exactly from there. "
+    "Respond ONLY to the latest user message "
+    "that appears AFTER this summary. The current session state (files, "
+    "config, etc.) may reflect work described here — avoid repeating it:"
+)
+
+
+def test_latest_message_wins_over_inherited_active_task():
+    """The handoff must explicitly privilege the latest user message over a
+    stale historical task snapshot — the core #35344 contract."""
+    lower = SUMMARY_PREFIX.lower()
+    assert "latest user message" in lower
+    assert HISTORICAL_TASK_HEADING.lower() in lower
+    # Conflict-resolution must be explicit, not implied.
+    assert "wins" in lower or "supersede" in lower
+    assert "discard" in lower
+    # The "consistent -> use as background" carveout licensed stale-task
+    # resumption on topic overlap (#41607, #38364) — it must stay gone.
+    assert "you may use the summary as background" not in lower
+    assert "topic overlap" in lower
+
+
+def test_no_resume_exactly_directive_can_hijack():
+    """The directive that caused the hijack ("resume exactly from Active
+    Task") must be gone."""
+    assert "resume exactly" not in SUMMARY_PREFIX.lower()
+
+
+def test_resumed_stale_handoff_gets_renormalized_to_current_prefix():
+    """A handoff persisted under the OLD conflicting prefix (e.g. saved before
+    the fix and inherited into a resumed lineage) is upgraded to the CURRENT
+    prefix when re-normalized on re-compaction — so the "resume exactly"
+    directive cannot survive into a resumed session."""
+    stale_body = (
+        f"{HISTORICAL_TASK_HEADING}\n"
+        "User asked: 'Migrate the billing module to Stripe'\n\n"
+        "## Goal\nMigrate billing.\n"
+    )
+    stale_handoff = f"{_OLD_CONFLICTING_PREFIX}\n{stale_body}"
+
+    # Sanity: the fixture really does carry the old directive.
+    assert "resume exactly" in stale_handoff.lower()
+
+    renormalized = ContextCompressor._with_summary_prefix(stale_handoff)
+
+    # The body is preserved...
+    assert "Migrate the billing module to Stripe" in renormalized
+    # ...but the conflicting directive is stripped and replaced with the
+    # current latest-message-wins framing.
+    assert "resume exactly" not in renormalized.lower()
+    assert renormalized.startswith(SUMMARY_PREFIX)
+    assert ("wins" in renormalized.lower()
+            or "priority" in renormalized.lower()
+            or "supersede" in renormalized.lower())
+
+
+def test_legacy_prefix_handoff_also_renormalized():
+    """The same upgrade applies to the oldest ``[CONTEXT SUMMARY]:`` handoff
+    format that may sit in a long-lived resumed lineage."""
+    legacy = f"{LEGACY_SUMMARY_PREFIX} {HISTORICAL_TASK_HEADING}\nUser asked: 'task A'"
+    renormalized = ContextCompressor._with_summary_prefix(legacy)
+    assert renormalized.startswith(SUMMARY_PREFIX)
+    assert LEGACY_SUMMARY_PREFIX not in renormalized
+    assert "task A" in renormalized
+
+
+def test_inherited_handoff_detected_in_resumed_protected_head():
+    """On a resumed lineage the handoff commonly sits right after the system
+    prompt (in the protected head). ``_find_latest_context_summary`` must
+    detect it there so re-compaction rehydrates state from it rather than
+    serializing it as a fresh user turn (which is what let the stale Active
+    Task read as live intent)."""
+    messages = [
+        {"role": "system", "content": "system prompt"},
+        {"role": "user", "content": f"{SUMMARY_PREFIX}\n{HISTORICAL_TASK_HEADING}\nUser asked: 'task A'"},
+        {"role": "assistant", "content": "ok"},
+        {"role": "user", "content": "Unrelated task B: what's the capital of France?"},
+    ]
+    # Search the whole post-system range.
+    idx, body = ContextCompressor._find_latest_context_summary(
+        messages, 1, len(messages)
+    )
+    assert idx == 1, "handoff in protected head must be found"
+    assert "task A" in body
+    # The detected body is stripped of the prefix (treated as state, not a
+    # standalone instruction message).
+    assert not body.startswith(SUMMARY_PREFIX)
+
+
+def test_historical_prefixed_handoff_detected_and_stripped():
+    """A pre-fix handoff (old conflicting prefix) inherited into a resumed
+    lineage must still be recognized as a context summary AND have its old
+    directive stripped on detection — otherwise re-compaction serializes the
+    stale 'resume exactly' text as a fresh turn."""
+    messages = [
+        {"role": "system", "content": "system prompt"},
+        {"role": "user", "content": f"{_OLD_CONFLICTING_PREFIX}\n{HISTORICAL_TASK_HEADING}\nUser asked: 'task A'"},
+        {"role": "assistant", "content": "ok"},
+        {"role": "user", "content": "Unrelated task B"},
+    ]
+    idx, body = ContextCompressor._find_latest_context_summary(
+        messages, 1, len(messages)
+    )
+    assert idx == 1
+    assert "task A" in body
+    assert "resume exactly" not in body.lower()