feat: add gated Gitea PR merge workflow (#16) #26

Merged
sysadmin merged 3 commits from feature/16-gated-gitea-pr-merge-workflow into master 2026-07-01 20:10:51 -05:00
3 changed files with 462 additions and 27 deletions
Showing only changes of commit f04cf44975 - Show all commits
+1 -1
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@@ -44,7 +44,7 @@ Any MCP-compatible agent (Antigravity, Claude Code, etc.) can call these tools n
| `gitea_edit_pr` | Edit details of an existing pull request |
| `gitea_list_prs` | List pull requests with state/remote |
| `gitea_view_pr` | Get full details of a single pull request |
| `gitea_merge_pr` | Merge a pull request (merge, squash, or rebase) |
| `gitea_merge_pr` | Gated merge: merge/squash/rebase only after identity+profile+eligibility gates pass, explicit `confirmation="MERGE PR <n>"`, optional head-SHA and changed-files pinning (no self-merge, no force) |
| `gitea_review_pr` | Legacy wrapper for `gitea_submit_pr_review` (merging disabled) |
| `gitea_delete_branch` | Delete a remote branch |
| `gitea_close_issue` | Close an issue by number |
+164 -18
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@@ -671,47 +671,193 @@ def gitea_commit_files(
}
# Merge methods supported by the Gitea merge API.
_MERGE_METHODS = ("merge", "squash", "rebase")
@mcp.tool()
def gitea_merge_pr(
pr_number: int,
confirmation: str = "",
expected_head_sha: str | None = None,
expected_changed_files: list[str] | None = None,
do: str = "merge",
title: str | None = None,
message: str | None = None,
force: bool = False,
remote: str = "dadeschools",
host: str | None = None,
org: str | None = None,
repo: str | None = None,
) -> dict:
"""Merge a Gitea pull request.
"""Gated merge of a Gitea pull request (#16).
This is the ONLY merge path this server exposes, and it mutates only after
every safety gate passes. No ungated merge tool remains: legacy
``gitea_review_pr`` fails closed on ``merge=True`` and
``gitea_submit_pr_review`` never merges.
Gate order (fail-closed at each step; the merge API is called only if all
gates pass):
1. Merge method (``do``) is 'merge', 'squash', or 'rebase'.
2. Explicit confirmation: ``confirmation`` must equal ``"MERGE PR <n>"``.
Without it, the tool makes no API calls at all.
3. Reuse ``gitea_check_pr_eligibility`` (#14) with action 'merge': this
proves the authenticated identity, the active profile (and that it
allows merge), the PR author, blocks self-merge, requires the PR to be
open, and fails closed when the PR is not mergeable or mergeability is
unknown.
4. If ``expected_head_sha`` is given and the PR head moved → refuse.
5. If ``expected_changed_files`` is given and the PR's changed file set
differs → refuse.
6. Redundant self-merge block (authenticated user == PR author).
No force / ignore-checks option is exposed. Gitea's own ``mergeable`` signal
(which reflects branch-protection required reviews and status checks) must
be positive, so required approval/check state is honoured, never bypassed.
Never returns the token, Authorization header, or any credential material.
Args:
pr_number: The PR number to merge.
confirmation: Must be exactly ``"MERGE PR <pr_number>"`` or merge is refused.
expected_head_sha: Strongly recommended. If set and the PR head differs, refuse.
expected_changed_files: Optional. If set and the PR's changed file set
differs, refuse.
do: Merge style — 'merge', 'squash', or 'rebase'.
title: Optional merge title.
message: Optional merge message.
force: Force merge, ignoring status checks.
title: Optional merge commit title.
message: Optional merge commit message.
remote: Known instance — 'dadeschools' or 'prgs'.
host: Override the Gitea host.
org: Override the owner/organization.
repo: Override the repository name.
Returns:
dict with 'success' and 'message'.
dict describing the attempt: performed, authenticated user, profile
name, PR author, PR number, head SHA checked, merge method,
reasons/gates passed or blocked, and merge result / merge commit if
available. Never secrets.
"""
h, o, r = _resolve(remote, host, org, repo)
auth = _auth(h)
url = f"{repo_api_url(h, o, r)}/pulls/{pr_number}/merge"
payload = {
"Do": do,
"force_merge": force,
do = (do or "").strip().lower()
result = {
"performed": False,
"authenticated_user": None,
"profile_name": get_profile()["profile_name"],
"pr_author": None,
"pr_number": pr_number,
"head_sha": None,
"expected_head_sha": expected_head_sha,
"merge_method": do,
"mergeable": None,
"remote": remote if remote in REMOTES else None,
"merge_result": None,
"merge_commit": None,
"reasons": [],
}
if title:
payload["MergeTitleField"] = title
if message:
payload["MergeMessageField"] = message
api_request("POST", url, auth, payload)
return {"success": True, "message": f"PR #{pr_number} merged via '{do}'."}
reasons = result["reasons"]
# Gate 1 — valid merge method (no API call on a bad method).
if do not in _MERGE_METHODS:
reasons.append(
f"unknown merge method '{do}'; expected one of {list(_MERGE_METHODS)}"
)
return result
# Gate 2 — explicit confirmation (fail fast; zero API calls without it).
expected_confirmation = f"MERGE PR {pr_number}"
if (confirmation or "").strip() != expected_confirmation:
reasons.append(
f"explicit confirmation required: pass confirmation='{expected_confirmation}'"
)
return result
# Gate 3 — reuse #14 eligibility (identity + profile + merge-allowed +
# author + self-merge block + open + mergeable/unknown fail-closed).
# Read-only GETs only.
elig = gitea_check_pr_eligibility(
pr_number=pr_number, action="merge", remote=remote,
host=host, org=org, repo=repo,
)
result["authenticated_user"] = elig.get("authenticated_user")
result["profile_name"] = elig.get("profile_name", result["profile_name"])
result["pr_author"] = elig.get("pr_author")
result["head_sha"] = elig.get("head_sha")
result["mergeable"] = elig.get("mergeable")
if not elig.get("eligible"):
reasons.append("eligibility check for 'merge' failed (fail closed)")
reasons.extend(elig.get("reasons", []))
return result
# Gate 4 — head SHA must match if the caller pinned a reviewed SHA.
actual_sha = result["head_sha"]
if expected_head_sha and actual_sha and expected_head_sha != actual_sha:
reasons.append(
"expected head SHA does not match current PR head (fail closed)"
)
return result
if not actual_sha:
# Unreachable — eligibility fails closed without a head SHA — but never
# merge a PR whose head commit we could not read.
reasons.append("PR head SHA unavailable (fail closed)")
return result
h, o, r = _resolve(remote, host, org, repo)
# Gate 5 — changed files must match the reviewed set, if provided.
if expected_changed_files is not None:
try:
auth = _auth(h)
files = api_request(
"GET", f"{repo_api_url(h, o, r)}/pulls/{pr_number}/files", auth
)
actual_files = sorted(
(f or {}).get("filename", "") for f in (files or [])
)
except Exception as exc: # noqa: BLE001 — redact before surfacing
reasons.append(
f"could not verify changed files (fail closed): {_redact(str(exc))}"
)
return result
result["changed_files"] = actual_files
if actual_files != sorted(expected_changed_files):
reasons.append(
"PR changed files do not match expected_changed_files (fail closed)"
)
return result
# Gate 6 — redundant self-merge block (belt-and-suspenders over #14).
auth_user = result["authenticated_user"]
pr_author = result["pr_author"]
if auth_user and pr_author and auth_user == pr_author:
reasons.append("self-merge blocked (authenticated user is PR author)")
return result
# All gates passed — perform the single merge mutation.
try:
auth = _auth(h)
merge_url = f"{repo_api_url(h, o, r)}/pulls/{pr_number}/merge"
payload = {"Do": do}
if title:
payload["MergeTitleField"] = title
if message:
payload["MergeMessageField"] = message
api_request("POST", merge_url, auth, payload)
# Best-effort read-back of the merge commit SHA (redacted on error).
try:
merged = api_request(
"GET", f"{repo_api_url(h, o, r)}/pulls/{pr_number}", auth
)
result["merge_commit"] = (merged or {}).get("merged_commit_sha")
except Exception:
result["merge_commit"] = None
except Exception as exc: # noqa: BLE001 — redact before surfacing
reasons.append(f"merge failed: {_redact(str(exc))}")
return result
result["performed"] = True
result["merge_result"] = f"PR #{pr_number} merged via '{do}'."
reasons.append(f"all gates passed; merged PR #{pr_number} via '{do}'")
return result
@mcp.tool()
+297 -8
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@@ -298,20 +298,309 @@ class TestViewPR(unittest.TestCase):
# Merge PR
# ---------------------------------------------------------------------------
class TestMergePR(unittest.TestCase):
"""Gated merge workflow (#16). gitea_merge_pr is the only merge path."""
def _pr(self, author, state="open", sha="abc123", mergeable=True):
return {
"user": {"login": author},
"state": state,
"head": {"sha": sha},
"mergeable": mergeable,
}
def _confirm(self, n):
return f"MERGE PR {n}"
def _assert_no_merge_call(self, mock_api):
for c in mock_api.call_args_list:
method, url = c.args[0], c.args[1]
self.assertFalse(
method == "POST" and url.endswith("/merge"),
f"unexpected merge mutation: {method} {url}",
)
# -- success --------------------------------------------------------------
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_merge_pr(self, _auth, mock_api):
mock_api.return_value = {}
result = gitea_merge_pr(pr_number=1, do="squash", title="T", message="M", force=True)
self.assertTrue(result["success"])
self.assertIn("merged", result["message"])
# Check payload
payload = mock_api.call_args[0][3]
def test_merge_succeeds_when_all_gates_pass(self, _auth, mock_api):
mock_api.side_effect = [
{"login": "merger-bot"}, self._pr("author-bot"),
{}, # merge POST
{"merged_commit_sha": "mergecommit99"}, # read-back
]
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8),
expected_head_sha="abc123", do="squash",
title="T", message="M", remote="prgs")
self.assertTrue(r["performed"])
self.assertEqual(r["authenticated_user"], "merger-bot")
self.assertEqual(r["pr_author"], "author-bot")
self.assertEqual(r["head_sha"], "abc123")
self.assertEqual(r["merge_method"], "squash")
self.assertEqual(r["merge_commit"], "mergecommit99")
# 3rd call is the merge POST with the requested method/title/message.
merge_call = mock_api.call_args_list[2]
self.assertEqual(merge_call.args[0], "POST")
self.assertTrue(merge_call.args[1].endswith("/pulls/8/merge"))
payload = merge_call.args[3]
self.assertEqual(payload["Do"], "squash")
self.assertEqual(payload["MergeTitleField"], "T")
self.assertEqual(payload["MergeMessageField"], "M")
self.assertEqual(payload["force_merge"], True)
self.assertNotIn("force_merge", payload)
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_expected_changed_files_match_allows(self, _auth, mock_api):
mock_api.side_effect = [
{"login": "merger-bot"}, self._pr("author-bot"),
[{"filename": "a.py"}, {"filename": "b.py"}], # files
{}, # merge POST
{"merged_commit_sha": "c1"}, # read-back
]
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8),
expected_changed_files=["b.py", "a.py"], remote="prgs")
self.assertTrue(r["performed"])
# -- confirmation ---------------------------------------------------------
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_missing_confirmation_blocks_with_no_api_call(self, _auth, mock_api):
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(pr_number=8, confirmation="", remote="prgs")
self.assertFalse(r["performed"])
self.assertTrue(any("explicit confirmation required" in x for x in r["reasons"]))
mock_api.assert_not_called()
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_wrong_confirmation_blocks(self, _auth, mock_api):
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(pr_number=8, confirmation="MERGE PR 9", remote="prgs")
self.assertFalse(r["performed"])
mock_api.assert_not_called()
# -- identity / profile / eligibility fail-closed -------------------------
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_self_author_cannot_merge(self, _auth, mock_api):
mock_api.side_effect = [{"login": "jcwalker3"}, self._pr("jcwalker3")]
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8), remote="prgs")
self.assertFalse(r["performed"])
self.assertIn("authenticated user is PR author", r["reasons"])
self._assert_no_merge_call(mock_api)
@patch("mcp_server.get_auth_header", return_value=None)
def test_unknown_identity_blocks(self, _auth):
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8), remote="prgs")
self.assertFalse(r["performed"])
self.assertIsNone(r["authenticated_user"])
self.assertIn("authenticated identity could not be determined", r["reasons"])
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_unknown_profile_blocks(self, _auth, mock_api):
mock_api.side_effect = [{"login": "merger-bot"}, self._pr("author-bot")]
env = {} # no GITEA_ALLOWED_OPERATIONS → empty allowed ops
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8), remote="prgs")
self.assertFalse(r["performed"])
self.assertIn(
"profile has no configured allowed operations (fail closed)",
r["reasons"])
self._assert_no_merge_call(mock_api)
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_profile_without_merge_permission_blocks(self, _auth, mock_api):
mock_api.side_effect = [{"login": "merger-bot"}, self._pr("author-bot")]
env = {"GITEA_PROFILE_NAME": "gitea-reviewer",
"GITEA_ALLOWED_OPERATIONS": "read,review,approve"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8), remote="prgs")
self.assertFalse(r["performed"])
self.assertIn("profile is not allowed to merge", r["reasons"])
self._assert_no_merge_call(mock_api)
# -- PR state / mergeability ----------------------------------------------
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_closed_pr_blocks(self, _auth, mock_api):
mock_api.side_effect = [
{"login": "merger-bot"}, self._pr("author-bot", state="closed")]
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8), remote="prgs")
self.assertFalse(r["performed"])
self.assertIn("PR is not open (state=closed)", r["reasons"])
self._assert_no_merge_call(mock_api)
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_non_mergeable_pr_blocks(self, _auth, mock_api):
mock_api.side_effect = [
{"login": "merger-bot"}, self._pr("author-bot", mergeable=False)]
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8), remote="prgs")
self.assertFalse(r["performed"])
self.assertIn("PR is not mergeable", r["reasons"])
self._assert_no_merge_call(mock_api)
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_unknown_mergeability_fails_closed(self, _auth, mock_api):
mock_api.side_effect = [
{"login": "merger-bot"}, self._pr("author-bot", mergeable=None)]
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8), remote="prgs")
self.assertFalse(r["performed"])
self.assertIn("PR mergeability unknown", r["reasons"])
self._assert_no_merge_call(mock_api)
# -- head SHA / changed files ---------------------------------------------
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_head_sha_mismatch_blocks(self, _auth, mock_api):
mock_api.side_effect = [
{"login": "merger-bot"}, self._pr("author-bot", sha="abc123")]
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8),
expected_head_sha="deadbeef", remote="prgs")
self.assertFalse(r["performed"])
self.assertIn(
"expected head SHA does not match current PR head (fail closed)",
r["reasons"])
self._assert_no_merge_call(mock_api)
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_changed_files_mismatch_blocks(self, _auth, mock_api):
mock_api.side_effect = [
{"login": "merger-bot"}, self._pr("author-bot"),
[{"filename": "a.py"}, {"filename": "c.py"}], # actual files
]
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8),
expected_changed_files=["a.py", "b.py"], remote="prgs")
self.assertFalse(r["performed"])
self.assertIn(
"PR changed files do not match expected_changed_files (fail closed)",
r["reasons"])
self._assert_no_merge_call(mock_api)
# -- misc -----------------------------------------------------------------
@patch("mcp_server.api_request")
def test_invalid_merge_method_rejected(self, mock_api):
with patch.dict(os.environ, {}, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation="MERGE PR 8", do="octopus", remote="prgs")
self.assertFalse(r["performed"])
self.assertTrue(any("unknown merge method" in x for x in r["reasons"]))
mock_api.assert_not_called()
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_output_redacts_secrets(self, _auth, mock_api):
mock_api.side_effect = [
{"login": "merger-bot"}, self._pr("author-bot"),
{}, {"merged_commit_sha": "c1"},
]
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge",
"GITEA_TOKEN": "super-secret-token"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8), remote="prgs")
blob = repr(r).lower()
for secret in ("super-secret-token", "authorization", "basic ", FAKE_AUTH.lower()):
self.assertNotIn(secret, blob)
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_merge_error_message_redacts_credential(self, _auth, mock_api):
mock_api.side_effect = [
{"login": "merger-bot"}, self._pr("author-bot"),
RuntimeError("HTTP 500: token abc-secret-xyz rejected"),
]
env = {"GITEA_PROFILE_NAME": "gitea-merger",
"GITEA_ALLOWED_OPERATIONS": "read,merge"}
with patch.dict(os.environ, env, clear=True):
r = gitea_merge_pr(
pr_number=8, confirmation=self._confirm(8), remote="prgs")
self.assertFalse(r["performed"])
blob = repr(r)
self.assertIn("[REDACTED]", blob)
self.assertNotIn("abc-secret-xyz", blob)
class TestNoUngatedMergePath(unittest.TestCase):
"""Prove no other exposed tool can merge (#16 surface audit)."""
def test_submit_pr_review_has_no_merge(self):
import inspect
import mcp_server
# No merge parameter on the review-mutation tool.
params = inspect.signature(mcp_server.gitea_submit_pr_review).parameters
self.assertNotIn("merge", params)
# And 'merge' is not a reviewable action.
self.assertNotIn("merge", mcp_server._REVIEW_ACTIONS)
@patch("mcp_server.api_request")
@patch("mcp_server.get_auth_header", return_value=FAKE_AUTH)
def test_review_pr_merge_true_makes_no_api_call(self, _auth, mock_api):
r = gitea_review_pr(pr_number=1, event="APPROVE", body="x", merge=True)
self.assertFalse(r["success"])
self.assertEqual(mock_api.call_count, 0)
def test_only_merge_endpoint_is_in_gated_tool(self):
# Source-level audit: the merge endpoint appears only inside
# gitea_merge_pr, which is the gated path.
import inspect
import mcp_server
src = inspect.getsource(mcp_server)
self.assertEqual(src.count("/merge\""), 1)
merge_src = inspect.getsource(mcp_server.gitea_merge_pr)
self.assertIn("/merge\"", merge_src)
# ---------------------------------------------------------------------------