fix(pr-pipeline): hold native lane PRs on marketplace and cost paths

.changes/pr-pipeline/fix-9449-native-lane-holds-cc7e4173.md

@@ -0,0 +1,7 @@
+---
+bump: patch
+---
+
+### Fixed
+
+- `ci-status` and `enable-auto-merge` hold a lanes App pull request that changes the marketplace manifest (until a trusted approval of the head) or a merge-gate cost path (until the owner's linked cost decision).

.changes/source-control/fix-9449-native-lane-holds-79900ccb.md

@@ -0,0 +1,7 @@
+---
+bump: patch
+---
+
+### Fixed
+
+- A test keeps the native auto-merge cost paths and manifest holds in step with `babysit_risk`.

.github/scripts/pr-merge/enable-auto-merge.mjs

@@ -22,6 +22,8 @@
 //   wrote its Hold: line can add one. The rule is merge-holds.pathHold, which
 //   ci-status also runs on every lanes App pull request event and merge
 //   group, so a push after arming is held without waiting for this job.
+// - Its head changes no cost path, unless its body links the owner's cost
+//   decision: merge-holds.costHold and costDecision, which ci-status runs too.
 // - No person turned its auto-merge off: the newest auto-merge-disabled event
 //   by a user account keeps it off until a person turns it on again.
 // - pr-merge's gate would take its verifier verdict at the head just read:
@@ -52,19 +54,22 @@
 //   TRACKER_CONFIG       the base .work-item-tracker.json, for the human-gated
 //                        label (default .base/.work-item-tracker.json)
 //   RESOLVED_CONFIG      the resolve-config output, for the hold paths
+//   TRUSTED_ACTORS       the base trusted-actors.json, for the owner of a cost
+//                        decision (default .base/.github/standards/trusted-actors/trusted-actors.json)
 //   EVENT_NAME           the run's event; only READER_EVENTS read verdicts and arm
 //   BABYSIT_VERIFY_*, BABYSIT_RUN_CACHE  the reader's Actions token (the
 //                        job's GITHUB_TOKEN), saved listing, head-ref map and
 //                        run cache, as the gate's
 //   GITHUB_API_URL
 import { spawnSync } from "node:child_process";
+import { readFileSync } from "node:fs";
 import process from "node:process";
 import { pathToFileURL } from "node:url";
 
 import { createGitHub } from "../../actions/check-trusted-trigger/check-trusted-trigger.mjs";
 import { humanGatedLabelFrom } from "../pr-unblock/address-feedback.mjs";
 import { readHoldPaths } from "../work-resolve-issue/report-outcome.mjs";
-import { BODY_HOLD, pathHold, vetoers } from "./merge-holds.mjs";
+import { BODY_HOLD, costDecision, costHold, humansOf, pathHold, vetoers } from "./merge-holds.mjs";
 
 export { BODY_HOLD, HUMAN_VETO } from "./merge-holds.mjs";
 
@@ -161,6 +166,17 @@ export function discussionHold(detail) {
   return vetoes.length ? `${vetoes.join(", ")} asked not to merge it` : null;
 }
 
+// The trusted-actor list's people; an unreadable list names none, so no cost
+// decision clears.
+function trustedHumans(env) {
+  try {
+    const { actors } = JSON.parse(readFileSync(env.TRUSTED_ACTORS || ".base/.github/standards/trusted-actors/trusted-actors.json", "utf8"));
+    return humansOf(actors);
+  } catch {
+    return new Set();
+  }
+}
+
 async function changedFiles(github, slug, number) {
   const paths = [];
   for (let page = 1; page <= MAX_FILE_PAGES; page += 1) {
@@ -245,7 +261,7 @@ export function decide(pull, { bot, humanGated, holdPaths = null }, detail) {
   if (detail === null) {
     return { action: "none", reason: "its discussion did not read" };
   }
-  const vetoed = pathHold(detail.files, holdPaths) ?? discussionHold(detail);
+  const vetoed = pathHold(detail.files, holdPaths) ?? costHold(detail.files, detail.costDecision) ?? discussionHold(detail);
   if (vetoed !== null) {
     return { action: armed ? "disarm" : "none", reason: vetoed };
   }
@@ -314,7 +330,9 @@ export async function main({ env = process.env, github, verify } = {}) {
           const variables = { owner: repo[1], name: repo[2], number: pull.number };
           detail = (await github("POST", "/graphql", { query: DETAIL_QUERY, variables }))?.data?.repository?.pullRequest ?? null;
           if (detail !== null) {
-            detail = { ...detail, files: await changedFiles(github, `${repo[1]}/${repo[2]}`, pull.number) };
+            const files = await changedFiles(github, `${repo[1]}/${repo[2]}`, pull.number);
+            const decision = costHold(files, null) ? await costDecision(github, repo[0], pull.number, pull.body, trustedHumans(env)) : null;
+            detail = { ...detail, files, costDecision: decision };
           }
         } catch (error) {
           console.log(`enable-auto-merge: #${pull.number} discussion did not read: ${escapeCommand(error?.message ?? error)}`);
@@ -339,12 +357,12 @@ export async function main({ env = process.env, github, verify } = {}) {
       }
       if (action === "none") {
         if (reason !== "not the lanes App's") {
-          console.log(`enable-auto-merge: #${pull.number} left: ${reason}`);
+          console.log(`enable-auto-merge: #${pull.number} left: ${escapeCommand(reason)}`);
         }
         continue;
       }
       if (!write) {
-        console.log(`enable-auto-merge: #${pull.number} would ${action} (report-only): ${reason}`);
+        console.log(`enable-auto-merge: #${pull.number} would ${action} (report-only): ${escapeCommand(reason)}`);
         continue;
       }
       try {
@@ -353,7 +371,7 @@ export async function main({ env = process.env, github, verify } = {}) {
           console.log(`enable-auto-merge: #${pull.number} armed at ${pull.headRefOid}`);
         } else {
           await github("POST", "/graphql", { query: DISARM_MUTATION, variables: { id: pull.id } });
-          console.log(`enable-auto-merge: #${pull.number} disarmed: ${reason}`);
+          console.log(`enable-auto-merge: #${pull.number} disarmed: ${escapeCommand(reason)}`);
         }
       } catch (error) {
         failed += 1;

.github/scripts/pr-merge/enable-auto-merge.test.mjs

@@ -26,7 +26,7 @@ import {
   main,
   verifyHold,
 } from "./enable-auto-merge.mjs";
-import { VERIFY_PATH, verdictHold } from "./merge-holds.mjs";
+import { COMMENT_EDITED_QUERY, PULL_OPENED_QUERY, VERIFY_PATH, verdictHold } from "./merge-holds.mjs";
 import { VERIFY_PATH as RESOLVER_VERIFY_PATH } from "../pr-verify/resolve-pr.mjs";
 import { decide as decideOutcome } from "../work-resolve-issue/report-outcome.mjs";
 
@@ -74,6 +74,15 @@ const said = (login, body, at, association = "OWNER", typename = "User") => ({
   authorAssociation: association,
 });
 const PASSED = { refusal: null, head: HEAD };
+const COST_LINK = `https://github.com/${REPO}/issues/1040#issuecomment-7`;
+const COST_COMMENT = {
+  issue_url: `https://api.github.com/repos/${REPO}/issues/1040`,
+  user: { login: "kyle-sexton", id: 5, type: "User" },
+  performed_via_github_app: null,
+  body: "**Decision recorded.** Cost: approve it.",
+  node_id: "IC_7",
+  created_at: "2026-10-22T12:00:00Z",
+};
 const labels = (...names) => ({ totalCount: names.length, nodes: names.map((name) => ({ name })) });
 
 function world(pulls, { failArm = false } = {}) {
@@ -85,7 +94,20 @@ function world(pulls, { failArm = false } = {}) {
       const files = pulls.find((candidate) => candidate.number === Number(listing[1]))?.files ?? [{ filename: "plugins/work-items/README.md" }];
       return files.slice((Number(listing[2]) - 1) * 100, Number(listing[2]) * 100);
     }
+    // The cost decision reads (merge-holds.costDecision): the owner's comment
+    // 7 on pull request 40's closing issue, and each pull request closes its own
+    // number plus 1000.
+    if (method === "GET" && path === "/repos/melodic-software/claude-code-plugins/issues/comments/7") {
+      return COST_COMMENT;
+    }
     assert.equal(`${method} ${path}`, "POST /graphql");
+    if (body.query === PULL_OPENED_QUERY) {
+      const nodes = [{ number: body.variables.number + 1000, repository: { nameWithOwner: REPO } }];
+      return { data: { repository: { pullRequest: { createdAt: "2026-10-22T10:00:00Z", closingIssuesReferences: { totalCount: 1, nodes } } } } };
+    }
+    if (body.query === COMMENT_EDITED_QUERY) {
+      return { data: { node: { lastEditedAt: null } } };
+    }
     if (body.query === PULLS_QUERY) {
       assert.deepEqual(body.variables, { owner: "melodic-software", name: "claude-code-plugins", after: null });
       return { data: { repository: { pullRequests: { pageInfo: { hasNextPage: false, endCursor: null }, nodes: pulls } } } };
@@ -112,9 +134,9 @@ function world(pulls, { failArm = false } = {}) {
   };
   const writes = () =>
     calls
-      .filter(({ method, body }) => method === "POST" && body.query !== PULLS_QUERY && body.query !== DETAIL_QUERY)
+      .filter(({ method, body }) => method === "POST" && ![PULLS_QUERY, DETAIL_QUERY, PULL_OPENED_QUERY, COMMENT_EDITED_QUERY].includes(body.query))
       .map(({ body }) => ({ mutation: body.query === ARM_MUTATION ? "arm" : body.query === DISARM_MUTATION ? "disarm" : "?", ...body.variables }));
-  return { github, writes, verify, verified };
+  return { github, writes, verify, verified, calls };
 }
 
 async function run(pulls, env = {}, options = {}) {
@@ -362,6 +384,49 @@ test("a pull request whose head now changes a hold path is not armed, or is disa
   ]);
 });
 
+// The gate scores the marketplace manifest HIGH (babysit_risk.is_manifest_path),
+// so it is a hold path like every plugin manifest.
+test("a pull request whose head changes the marketplace manifest is not armed, or is disarmed", () => {
+  const options = { bot: LANES.login, humanGated: "needs-human", holdPaths: [] };
+  const files = ["docs/a.md", ".claude-plugin/marketplace.json"];
+  assert.deepEqual(decide(pull(1), options, { ...detail(), files, verify: PASSED }), {
+    action: "none",
+    reason: "it changes .claude-plugin/marketplace.json, a hold path",
+  });
+  assert.equal(decide(pull(1, { autoMergeRequest: {} }), options, { ...detail(), files, verify: PASSED }).action, "disarm");
+});
+
+// The gate holds a cost path (babysit_risk.COST_PATHS) until the body links
+// the owner's cost decision (babysit_merge_policy.cost_decision).
+test("a cost path holds until the body links the owner's cost decision", async () => {
+  const options = { bot: LANES.login, humanGated: "needs-human", holdPaths: [] };
+  const files = ["infra/Pulumi.prod.yaml"];
+  assert.deepEqual(decide(pull(1), options, { ...detail(), files, verify: PASSED }), {
+    action: "none",
+    reason: "it changes infra/Pulumi.prod.yaml, a cost path",
+  });
+  assert.equal(decide(pull(1, { autoMergeRequest: {} }), options, { ...detail(), files, verify: PASSED }).action, "disarm");
+  assert.equal(decide(pull(1), options, { ...detail(), files, costDecision: COST_LINK, verify: PASSED }).action, "arm");
+
+  const dir = mkdtempSync(join(tmpdir(), "enable-auto-merge-"));
+  writeFileSync(join(dir, "actors.json"), JSON.stringify({ actors: [{ kind: "human", login: "kyle-sexton", id: 5 }] }));
+  const cost = [{ filename: "plugins/multi-agent/reference/defaults.yaml" }];
+  const decided = `Closes #1040\n\nCost decision: ${COST_LINK}`;
+  const { writes } = await run(
+    [pull(40, { files: cost, body: decided }), pull(41, { files: cost }), pull(42, { files: cost, body: decided })],
+    { TRUSTED_ACTORS: join(dir, "actors.json") },
+  );
+  // Pull request 41 links no decision; 42 closes a different issue, so pull
+  // request 40's decision does not cover it.
+  assert.deepEqual(writes, [{ mutation: "arm", id: "PR_40", head: HEAD }]);
+  // A changed file's name cannot start a workflow command on its own line.
+  const { lines } = await run([pull(43, { files: [{ filename: "x\n::warning::forged/main.tf" }] })]);
+  assert.ok(lines.some((line) => line.includes("x ::warning::forged/main.tf, a cost path")));
+  assert.ok(!lines.some((line) => /(^|\n)::warning::/.test(line)));
+  // Not on the trusted-actor list, the commenter decides nothing.
+  assert.deepEqual((await run([pull(40, { files: cost, body: decided })], { TRUSTED_ACTORS: "/nonexistent/actors.json" })).writes, []);
+});
+
 // ci-status runs merge-holds.mjs on the live files with the base config's
 // denied paths, by the same pathHold that decides arming above.
 test("merge-holds.mjs holds a changed or renamed-from hold path from the command line", () => {