Merge pull request 'feat: enforce PR review/merge workflow state machine gates (Closes #290)' (#378) from feat/issue-290-review-merge-state-machine into master

gitea_mcp_server.py

@@ -478,6 +478,7 @@ import agent_temp_artifacts
 import issue_lock_worktree  # noqa: E402
 import issue_claim_heartbeat  # noqa: E402
 import merged_cleanup_reconcile  # noqa: E402
+import review_merge_state_machine  # noqa: E402
 import native_mcp_preference  # noqa: E402
 
 
@@ -4084,6 +4085,14 @@ _GUIDE_RULES = {
         "inventory, summarize) needs no explicit authorization. Enforced "
         "fail closed via subagent_gate.assess_subagent_delegation and "
         "validate_subagent_report (#266)."),
+    "review_merge_state_machine": (
+        "PR review/merge must follow the enforced state machine: PRECHECK → "
+        "INVENTORY → SELECT_PR → PIN_HEAD_SHA → CREATE_BRANCHES_WORKTREE → "
+        "VALIDATE → REVIEW_DECISION → APPROVE_OR_REQUEST_CHANGES → "
+        "PRE_MERGE_RECHECK → MERGE → POST_MERGE_REPORT. Failed upstream "
+        "states forbid downstream approve/merge. infra_stop and capability "
+        "blocks stop immediately. Blocked recovery handoffs must restart the "
+        "full workflow — never replay approve/merge commands (#290)."),
     "native_mcp_preference": (
         "Gitea mutations must use native MCP tools first. When MCP is "
         "available, block shell scripts, direct API calls, WebFetch, "
@@ -4797,6 +4806,65 @@ def _build_runtime_task_capabilities(
 
 
 @mcp.tool()
+def gitea_assess_review_merge_state_machine(
+    target_state: str | None = None,
+    state_completion: dict[str, bool] | None = None,
+    pre_merge_gates: dict[str, bool] | None = None,
+    infra_stop: bool = False,
+    capability_blocked: bool = False,
+    recovery_handoff_text: str | None = None,
+    final_report_text: str | None = None,
+) -> dict:
+    """Read-only: assess enforced PR review/merge workflow state (#290)."""
+    completion = state_completion or {}
+    blockers = review_merge_state_machine.assess_workflow_blockers(
+        infra_stop=infra_stop,
+        capability_blocked=capability_blocked,
+    )
+    result = {
+        "workflow": review_merge_state_machine.workflow_status(
+            completion,
+            infra_stop=infra_stop,
+            capability_blocked=capability_blocked,
+        ),
+        "blockers": blockers,
+        "approve": review_merge_state_machine.can_approve(
+            completion,
+            infra_stop=infra_stop,
+            capability_blocked=capability_blocked,
+        ),
+        "merge": review_merge_state_machine.can_merge(
+            completion,
+            pre_merge_gates=pre_merge_gates,
+            infra_stop=infra_stop,
+            capability_blocked=capability_blocked,
+        ),
+    }
+    if target_state:
+        result["advancement"] = review_merge_state_machine.assess_state_advancement(
+            completion,
+            target_state=target_state,
+            infra_stop=infra_stop,
+            capability_blocked=capability_blocked,
+        )
+    if recovery_handoff_text is not None:
+        result["recovery_handoff"] = (
+            review_merge_state_machine.assess_blocked_recovery_handoff(
+                recovery_handoff_text
+            )
+        )
+    if final_report_text is not None:
+        result["final_report_claims"] = (
+            review_merge_state_machine.assess_final_report_state_claims(
+                final_report_text,
+                state_completion=completion,
+                approve_completed=bool(completion.get("APPROVE_OR_REQUEST_CHANGES")),
+                merge_completed=bool(completion.get("MERGE")),
+            )
+        )
+    return result
+
+
 @mcp.tool()
 def gitea_assess_gitea_operation_path(
     task: str,

review_merge_state_machine.py

@@ -0,0 +1,332 @@
+"""Enforced PR review/merge workflow state machine (#290).
+
+Review and merge must advance through explicit states. Any failed upstream
+gate forbids downstream approve/merge mutations until the full workflow is
+restarted after blockers clear.
+"""
+
+from __future__ import annotations
+
+import re
+from typing import Any
+
+REVIEW_MERGE_STATES: tuple[str, ...] = (
+    "PRECHECK",
+    "INVENTORY",
+    "SELECT_PR",
+    "PIN_HEAD_SHA",
+    "CREATE_BRANCHES_WORKTREE",
+    "VALIDATE",
+    "REVIEW_DECISION",
+    "APPROVE_OR_REQUEST_CHANGES",
+    "PRE_MERGE_RECHECK",
+    "MERGE",
+    "POST_MERGE_REPORT",
+)
+
+TERMINAL_BLOCKED_HEADING = (
+    "PR review/merge workflow blocked. Restart the full workflow after blockers clear."
+)
+
+_FORBIDDEN_RECOVERY_REPLAY_RE = re.compile(
+    r"\b(?:approve(?:\s+pr)?\s*#?\d+|merge(?:\s+pr)?\s*#?\d+|gitea_merge_pr|"
+    r"gitea_submit_pr_review|submit\s+approve|run\s+merge)\b",
+    re.IGNORECASE,
+)
+_RESTART_WORKFLOW_RE = re.compile(
+    r"restart(?:\s+the)?\s+full\s+workflow|rerun\s+the\s+full\s+workflow",
+    re.IGNORECASE,
+)
+_READY_TO_MERGE_RE = re.compile(
+    r"\bready\s+to\s+merge\b",
+    re.IGNORECASE,
+)
+_REVIEWED_VALIDATED_RE = re.compile(
+    r"\b(?:reviewed|validated|approval\s+submitted)\b",
+    re.IGNORECASE,
+)
+
+_PRE_MERGE_REQUIRED_GATES = (
+    "whoami_verified",
+    "profile_runtime_verified",
+    "merge_capability_verified",
+    "pr_refetched",
+    "reviewed_head_sha_unchanged",
+    "pr_mergeable",
+    "checks_passed",
+    "reviewer_not_author",
+    "worktree_clean",
+)
+
+
+def _clean(value: str | None) -> str:
+    return (value or "").strip()
+
+
+def state_index(state: str) -> int:
+    name = _clean(state).upper()
+    try:
+        return REVIEW_MERGE_STATES.index(name)
+    except ValueError as exc:
+        raise ValueError(f"unknown review/merge state '{state}' (fail closed)") from exc
+
+
+def downstream_states(from_state: str) -> list[str]:
+    idx = state_index(from_state)
+    return list(REVIEW_MERGE_STATES[idx + 1 :])
+
+
+def _completed_through(state_completion: dict[str, bool], state: str) -> bool:
+    return bool(state_completion.get(state))
+
+
+def _first_incomplete_state(state_completion: dict[str, bool]) -> str | None:
+    for state in REVIEW_MERGE_STATES:
+        if not _completed_through(state_completion, state):
+            return state
+    return None
+
+
+def assess_workflow_blockers(
+    *,
+    infra_stop: bool = False,
+    capability_blocked: bool = False,
+    mcp_reconnect_failed: bool = False,
+    stale_capability_state: bool = False,
+) -> dict[str, Any]:
+    """Return hard blockers that forbid all PR queue work (#290 AC3)."""
+    reasons: list[str] = []
+    if infra_stop:
+        reasons.append("infra_stop is active; PR selection/review/merge is forbidden")
+    if capability_blocked:
+        reasons.append("gitea_resolve_task_capability returned blocked/stop_required")
+    if mcp_reconnect_failed:
+        reasons.append("MCP reconnect failed; stale session state cannot be reused")
+    if stale_capability_state:
+        reasons.append("stale MCP capability state detected after reconnect failure")
+    return {
+        "block": bool(reasons),
+        "reasons": reasons,
+        "forbidden_states": list(REVIEW_MERGE_STATES) if reasons else [],
+        "safe_next_action": (
+            TERMINAL_BLOCKED_HEADING if reasons else "proceed with PRECHECK"
+        ),
+    }
+
+
+def assess_state_advancement(
+    state_completion: dict[str, bool] | None,
+    *,
+    target_state: str,
+    infra_stop: bool = False,
+    capability_blocked: bool = False,
+) -> dict[str, Any]:
+    """Fail closed when *target_state* is requested before upstream gates pass."""
+    completion = dict(state_completion or {})
+    target = _clean(target_state).upper()
+    blockers = assess_workflow_blockers(
+        infra_stop=infra_stop,
+        capability_blocked=capability_blocked,
+    )
+    reasons = list(blockers["reasons"])
+
+    try:
+        target_idx = state_index(target)
+    except ValueError as exc:
+        return {
+            "target_state": target,
+            "allowed": False,
+            "block": True,
+            "reasons": [str(exc)],
+            "next_allowed_state": None,
+            "safe_next_action": TERMINAL_BLOCKED_HEADING,
+        }
+
+    if blockers["block"]:
+        return {
+            "target_state": target,
+            "allowed": False,
+            "block": True,
+            "reasons": reasons,
+            "next_allowed_state": None,
+            "safe_next_action": blockers["safe_next_action"],
+        }
+
+    next_allowed = _first_incomplete_state(completion)
+    if next_allowed is None:
+        allowed = target_idx == len(REVIEW_MERGE_STATES) - 1
+        if not allowed:
+            reasons.append("workflow already completed through POST_MERGE_REPORT")
+    else:
+        allowed = state_index(next_allowed) >= target_idx
+        if not allowed:
+            reasons.append(
+                f"state '{target}' is forbidden until '{next_allowed}' completes"
+            )
+
+    return {
+        "target_state": target,
+        "allowed": allowed and not reasons,
+        "block": bool(reasons),
+        "reasons": reasons,
+        "next_allowed_state": next_allowed,
+        "completed_states": [s for s in REVIEW_MERGE_STATES if completion.get(s)],
+        "safe_next_action": (
+            f"complete state '{next_allowed}' before advancing"
+            if next_allowed and not allowed
+            else (
+                TERMINAL_BLOCKED_HEADING
+                if reasons
+                else f"advance to {target}"
+            )
+        ),
+    }
+
+
+def can_approve(state_completion: dict[str, bool] | None, **blocker_kwargs) -> dict[str, Any]:
+    """Approval requires all states through REVIEW_DECISION (#290 AC)."""
+    required = REVIEW_MERGE_STATES[: REVIEW_MERGE_STATES.index("REVIEW_DECISION") + 1]
+    completion = dict(state_completion or {})
+    advance = assess_state_advancement(
+        completion,
+        target_state="APPROVE_OR_REQUEST_CHANGES",
+        **blocker_kwargs,
+    )
+    missing = [s for s in required if not completion.get(s)]
+    reasons = list(advance["reasons"])
+    if missing:
+        reasons.append(
+            "approval blocked: incomplete states: " + ", ".join(missing)
+        )
+    block = bool(reasons) or advance["block"]
+    return {
+        "allowed": not block,
+        "block": block,
+        "reasons": reasons,
+        "missing_states": missing,
+        "safe_next_action": advance["safe_next_action"],
+    }
+
+
+def can_merge(
+    state_completion: dict[str, bool] | None,
+    *,
+    pre_merge_gates: dict[str, bool] | None = None,
+    **blocker_kwargs,
+) -> dict[str, Any]:
+    """Merge requires approve path plus fresh PRE_MERGE_RECHECK gates (#290 AC6)."""
+    completion = dict(state_completion or {})
+    approve = can_approve(completion, **blocker_kwargs)
+    reasons = list(approve["reasons"])
+
+    if not completion.get("APPROVE_OR_REQUEST_CHANGES"):
+        reasons.append("merge blocked: APPROVE_OR_REQUEST_CHANGES not completed")
+
+    gate_map = dict(pre_merge_gates or {})
+    missing_gates = [g for g in _PRE_MERGE_REQUIRED_GATES if not gate_map.get(g)]
+    if missing_gates:
+        reasons.append(
+            "merge blocked: pre-merge gates incomplete: " + ", ".join(missing_gates)
+        )
+
+    advance = assess_state_advancement(
+        completion,
+        target_state="MERGE",
+        **blocker_kwargs,
+    )
+    reasons.extend(advance["reasons"])
+
+    block = bool(reasons)
+    return {
+        "allowed": not block,
+        "block": block,
+        "reasons": reasons,
+        "missing_pre_merge_gates": missing_gates,
+        "safe_next_action": (
+            "complete PRE_MERGE_RECHECK with fresh whoami/capability/PR re-fetch "
+            "before merge"
+            if block
+            else "merge allowed"
+        ),
+    }
+
+
+def assess_blocked_recovery_handoff(report_text: str) -> dict[str, Any]:
+    """Blocked handoffs must not replay approve/merge commands (#290 AC4)."""
+    text = report_text or ""
+    reasons: list[str] = []
+    if _FORBIDDEN_RECOVERY_REPLAY_RE.search(text):
+        reasons.append(
+            "blocked recovery handoff contains direct approve/merge replay command"
+        )
+    if reasons and not _RESTART_WORKFLOW_RE.search(text):
+        reasons.append(
+            "blocked recovery handoff must direct operator to restart full workflow"
+        )
+    return {
+        "block": bool(reasons),
+        "allowed": not reasons,
+        "reasons": reasons,
+        "safe_next_action": (
+            "remove approve/merge replay commands and say to restart full workflow "
+            "after blockers clear"
+            if reasons
+            else "recovery handoff wording acceptable"
+        ),
+    }
+
+
+def assess_final_report_state_claims(
+    report_text: str,
+    *,
+    state_completion: dict[str, bool] | None = None,
+    approve_completed: bool = False,
+    merge_completed: bool = False,
+) -> dict[str, Any]:
+    """Reports must not claim reviewed/ready-to-merge without gate proof (#290 AC10)."""
+    text = report_text or ""
+    completion = dict(state_completion or {})
+    reasons: list[str] = []
+
+    if _READY_TO_MERGE_RE.search(text) and not (
+        merge_completed or completion.get("PRE_MERGE_RECHECK")
+    ):
+        reasons.append(
+            "report claims ready-to-merge without PRE_MERGE_RECHECK completion"
+        )
+
+    if _REVIEWED_VALIDATED_RE.search(text):
+        if not (approve_completed or completion.get("VALIDATE")):
+            reasons.append(
+                "report claims reviewed/validated without VALIDATE/APPROVE proof"
+            )
+
+    return {
+        "block": bool(reasons),
+        "allowed": not reasons,
+        "reasons": reasons,
+        "safe_next_action": (
+            "remove stale reviewed/ready-to-merge claims unless gates passed"
+            if reasons
+            else "final report state claims consistent with workflow"
+        ),
+    }
+
+
+def workflow_status(
+    state_completion: dict[str, bool] | None,
+    **blocker_kwargs,
+) -> dict[str, Any]:
+    """Summarize current state-machine position for MCP/runtime reporting."""
+    completion = dict(state_completion or {})
+    blockers = assess_workflow_blockers(**blocker_kwargs)
+    next_state = _first_incomplete_state(completion)
+    return {
+        "states": list(REVIEW_MERGE_STATES),
+        "completed_states": [s for s in REVIEW_MERGE_STATES if completion.get(s)],
+        "next_required_state": next_state,
+        "workflow_complete": next_state is None,
+        "approve_allowed": can_approve(completion, **blocker_kwargs)["allowed"],
+        "merge_allowed": can_merge(completion, **blocker_kwargs)["allowed"],
+        "blockers": blockers,
+    }

tests/test_review_merge_state_machine.py

@@ -0,0 +1,121 @@
+"""Tests for enforced PR review/merge state machine (#290)."""
+import sys
+import unittest
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+import review_merge_state_machine as rmsm  # noqa: E402
+
+FULL_REVIEW_COMPLETION = {state: True for state in rmsm.REVIEW_MERGE_STATES}
+
+
+def _completion_through(state_name: str) -> dict[str, bool]:
+    idx = rmsm.state_index(state_name)
+    return {state: i <= idx for i, state in enumerate(rmsm.REVIEW_MERGE_STATES)}
+
+
+class TestWorkflowBlockers(unittest.TestCase):
+    def test_infra_stop_blocks_all_states(self):
+        result = rmsm.assess_workflow_blockers(infra_stop=True)
+        self.assertTrue(result["block"])
+        self.assertEqual(result["forbidden_states"], list(rmsm.REVIEW_MERGE_STATES))
+
+    def test_infra_stop_forbids_advancement(self):
+        result = rmsm.assess_state_advancement(
+            {},
+            target_state="INVENTORY",
+            infra_stop=True,
+        )
+        self.assertTrue(result["block"])
+        self.assertFalse(result["allowed"])
+
+
+class TestStateAdvancement(unittest.TestCase):
+    def test_cannot_skip_inventory(self):
+        result = rmsm.assess_state_advancement(
+            {"PRECHECK": True},
+            target_state="SELECT_PR",
+        )
+        self.assertTrue(result["block"])
+        self.assertEqual(result["next_allowed_state"], "INVENTORY")
+
+    def test_sequential_advance_allowed(self):
+        completion = _completion_through("INVENTORY")
+        result = rmsm.assess_state_advancement(
+            completion,
+            target_state="SELECT_PR",
+        )
+        self.assertFalse(result["block"])
+        self.assertTrue(result["allowed"])
+
+
+class TestApproveAndMergeGates(unittest.TestCase):
+    def test_approve_blocked_without_validate(self):
+        completion = _completion_through("PIN_HEAD_SHA")
+        result = rmsm.can_approve(completion)
+        self.assertTrue(result["block"])
+        self.assertIn("VALIDATE", ",".join(result["missing_states"]))
+
+    def test_approve_allowed_when_review_path_complete(self):
+        completion = _completion_through("REVIEW_DECISION")
+        result = rmsm.can_approve(completion)
+        self.assertFalse(result["block"])
+        self.assertTrue(result["allowed"])
+
+    def test_merge_blocked_without_pre_merge_gates(self):
+        completion = _completion_through("APPROVE_OR_REQUEST_CHANGES")
+        result = rmsm.can_merge(completion)
+        self.assertTrue(result["block"])
+        self.assertTrue(result["missing_pre_merge_gates"])
+
+    def test_merge_allowed_with_pre_merge_gates(self):
+        completion = _completion_through("PRE_MERGE_RECHECK")
+        gates = {gate: True for gate in rmsm._PRE_MERGE_REQUIRED_GATES}
+        result = rmsm.can_merge(completion, pre_merge_gates=gates)
+        self.assertFalse(result["block"])
+        self.assertTrue(result["allowed"])
+
+    def test_merge_blocked_when_head_sha_gate_fails(self):
+        completion = _completion_through("PRE_MERGE_RECHECK")
+        gates = {gate: True for gate in rmsm._PRE_MERGE_REQUIRED_GATES}
+        gates["reviewed_head_sha_unchanged"] = False
+        result = rmsm.can_merge(completion, pre_merge_gates=gates)
+        self.assertTrue(result["block"])
+        self.assertIn("reviewed_head_sha_unchanged", result["missing_pre_merge_gates"])
+
+
+class TestRecoveryHandoff(unittest.TestCase):
+    def test_blocked_handoff_without_replay_passes(self):
+        report = (
+            "Blocked recovery handoff.\n"
+            "Restart the full workflow after infra_stop clears.\n"
+            "No approve/merge performed."
+        )
+        result = rmsm.assess_blocked_recovery_handoff(report)
+        self.assertFalse(result["block"])
+
+    def test_blocked_handoff_with_merge_replay_fails(self):
+        report = "Please merge PR #12 now using gitea_merge_pr."
+        result = rmsm.assess_blocked_recovery_handoff(report)
+        self.assertTrue(result["block"])
+
+
+class TestFinalReportClaims(unittest.TestCase):
+    def test_ready_to_merge_claim_without_gates_fails(self):
+        result = rmsm.assess_final_report_state_claims(
+            "PR is ready to merge after validation.",
+            state_completion=_completion_through("VALIDATE"),
+        )
+        self.assertTrue(result["block"])
+
+    def test_reviewed_claim_without_validate_fails(self):
+        result = rmsm.assess_final_report_state_claims(
+            "PR reviewed and looks good.",
+            state_completion={"PRECHECK": True},
+        )
+        self.assertTrue(result["block"])
+
+
+if __name__ == "__main__":
+    unittest.main()