From 24913064ff33ced14d79c488ae4c6ae611c576ec Mon Sep 17 00:00:00 2001 From: Tonio Date: Fri, 21 Aug 2026 16:44:26 -0700 Subject: [PATCH] feat(commitperclip): surface the Co-Authored-By trailers a squash merge needs (#11498) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ## Thinking Path > - Paperclip is the open source app people use to manage AI agents for work, and it takes contributions from outside the core team > - Those contributions arrive as PRs, and this repository squash-merges every one of them > - A squash collapses the whole branch into a single commit authored by whoever pressed the button > - So when a maintainer rebases and lands a contributor's stale PR, the contributor's name survives only if the squash message carries a `Co-Authored-By` trailer > - Nothing prompts for that trailer, and the PR page keeps showing the original author either way, so losing it is invisible at the moment it happens > - This pull request has commitperclip detect the situation and print the exact trailers to paste > - The benefit is that keeping an outside contributor's name is a default rather than something a maintainer has to remember ## Linked Issues or Issue Description No public issue exists. The problem follows, and it is not hypothetical. **What happened?** #11370, #11371 and #11379 landed @stubbi's work yesterday. Each of those PRs carries a comment from me telling them their authorship would be preserved. All three squash commits went in without a `Co-Authored-By` trailer, so `git log` credits none of them: | commit | landed from | credited | | --- | --- | --- | | `66515582e` | #9900 | Claude only | | `bc0b5a164` | #9501 | Claude only | | `35a9b9873` | #8982 | Claude only | | `6542ad1f4` | #11259 | ✅ Jannes Stubbemann + Claude | The last one has the trailer because that message was written by hand with the contributor in mind. The only difference between the two outcomes was memory. Master history cannot be rewritten, so those three are now credited by comment on the original PRs — which is a worse record than a commit trailer, and the reason to make this automatic. **Expected behavior** When a branch carries commits by someone other than the PR author, the merger is told what trailers the squash needs. **Paperclip version or commit** `master` at `92047cac4`. ## What Changed - `.github/scripts/check-pr-coauthors.mjs` — new gate. - `.github/scripts/run-quality-gates.mjs` — fetches the PR's commits and runs it. - `.github/scripts/tests/check-pr-coauthors.test.mjs` — 12 cases. - `.github/workflows/pr.yml` — runs `.github/scripts/tests/`. ### Informational, not a failure The squash message does not exist while the PR is open. This can neither be verified there nor fixed there, so failing a PR on it would block work on something its author cannot satisfy. The gate notices that the situation applies and prints the lines to paste. Run against #11370's actual commits it produces exactly what was missing: ``` This branch carries commits by stubbi. Squash-merging drops that authorship unless the squash message carries their trailers, and nothing else will notice if it does not. Add to the squash body when merging: Co-Authored-By: Jannes Stubbemann ``` ### Edge cases it handles Bots skipped; the PR author's own commits skipped; logins compared case-insensitively (`PR_AUTHOR` does not always arrive in the same case as the commit author login); each contributor listed once however many commits they wrote; and a commit GitHub could not match to an account falls back to its raw git author — that identity being the one most likely to be lost, not least likely. Paging stops at the API's own 250-commit ceiling rather than spinning on full pages of nothing new. ### The test directory was not running `.github/scripts/tests/` held ten test files covering the existing gates, and no workflow ran any of them. Adding an eleventh would have meant adding a test that never executes, so `pr.yml` now runs the directory. All **149** pass, including the 137 that were already there and previously unverified in CI. ## Verification - 149 tests pass via `node --test '.github/scripts/tests/*.test.mjs'` — the exact command CI now runs. - The gate was run against the real commit shape from #11370 and produces the missing trailer verbatim. This PR is its own negative control: the branch carries only my commits, so the new gate should stay silent on it. If commitperclip prints a co-author note below, the gate is wrong. ## Risks Low. Informational output only — it cannot fail a PR, and `allPassed` is unchanged. It adds one API call per gate run (`/pulls/{n}/commits`), fetched in the same `Promise.all` as the existing PR and files calls. Enabling the previously-unrun test directory could in principle surface a pre-existing failure; all 149 pass locally, so it does not. Revert the commit to restore. ## Model Used Claude Opus 5 (`claude-opus-5`), through Claude Code. Extended thinking enabled. Tool use enabled: file read and edit, shell for test runs. ## Checklist - [x] I have included a thinking path that traces from project context to this change - [x] I have specified the model used (with version and capability details) - [x] I have checked ROADMAP.md and confirmed this PR does not duplicate planned core work - [x] I have searched GitHub for duplicate or related PRs and linked them above - [x] I have either (a) linked existing issues with `Fixes: #` / `Closes #` / `Refs #` OR (b) described the issue in-PR following the relevant issue template - [x] I have not referenced internal/instance-local Paperclip issues or links - [x] My branch name describes the change and contains no internal ticket id - [x] I have run tests locally and they pass - [x] I have added or updated tests where applicable - [x] I have updated relevant documentation to reflect my changes - [x] I have considered and documented any risks above - [x] All Paperclip CI gates are green - [x] Greptile is 5/5 with no open P2s, recommendations, or follow-ups - [x] I will address all Greptile and reviewer comments before requesting merge --------- Co-authored-by: Claude Opus 5 --- .github/scripts/check-pr-coauthors.mjs | 135 +++++++++++++ .github/scripts/run-quality-gates.mjs | 14 ++ .../scripts/tests/check-pr-coauthors.test.mjs | 179 ++++++++++++++++++ .github/workflows/pr.yml | 2 + 4 files changed, 330 insertions(+) create mode 100644 .github/scripts/check-pr-coauthors.mjs create mode 100644 .github/scripts/tests/check-pr-coauthors.test.mjs diff --git a/.github/scripts/check-pr-coauthors.mjs b/.github/scripts/check-pr-coauthors.mjs new file mode 100644 index 0000000000..13239dd8e1 --- /dev/null +++ b/.github/scripts/check-pr-coauthors.mjs @@ -0,0 +1,135 @@ +#!/usr/bin/env node +/** + * check-pr-coauthors.mjs + * Surfaces the `Co-Authored-By` trailers a squash merge needs to keep + * contributors credited. + * Export: checkCoauthors(commits, prAuthor) → { passed, informational } + * + * This repository squash-merges, so every commit on a branch collapses into + * one commit authored by whoever presses the button. When a branch carries + * someone else's work — a rebase of a stale contributor PR, a port of an + * abandoned branch, a pairing session — their name survives only if the squash + * message carries a `Co-Authored-By` trailer for them. Nothing prompts for it, + * and the PR page keeps showing the original author either way, so the loss is + * invisible at exactly the moment it happens. + * + * Identity matching is a heuristic and is deliberately biased. A commit GitHub + * could not match to an account is credited unless its name or email resolves + * to the PR author, which will occasionally credit someone as a co-author of + * themselves — their git config carrying a real name where the comparison has + * only a login. That error costs a line a human drops while pasting. The + * opposite error costs a contributor their attribution silently, which is the + * failure this gate exists to prevent, so the bias runs towards over-crediting. + * + * Informational rather than a failure, on purpose. The squash message does not + * exist while the PR is open, so this cannot be verified here and cannot be + * fixed here either. Failing the PR would block work on something its author + * has no way to satisfy. What this can do is notice that the situation applies + * and hand over the exact lines to paste. + */ +import { fileURLToPath } from 'node:url'; + +/** + * Fetches every commit on a PR across GitHub pagination. + * + * Capped at the API's own ceiling: `/pulls/{n}/commits` returns at most 250 + * commits and silently stops. A branch that large is not the case this gate is + * about, and a partial list still surfaces the contributors it did see. + */ +export async function fetchAllPullRequestCommits(ghFetchFn, repo, prNumber, token) { + const commits = []; + + for (let page = 1; page <= 3; page += 1) { + const batch = await ghFetchFn( + `/repos/${repo}/pulls/${prNumber}/commits?per_page=100&page=${page}`, + token + ); + commits.push(...batch); + + if (batch.length < 100) break; + } + + return commits; +} + +/** GitHub's own no-reply address for a login, which is what trailers should use. */ +function noReplyEmail(login) { + return `${login}@users.noreply.github.com`; +} + +export function checkCoauthors(commits, prAuthor) { + const author = (prAuthor ?? '').toLowerCase(); + const contributors = new Map(); + // Emails already accounted for under a GitHub login. One person can appear + // both ways in the same branch — some commits matched to their account, some + // authored with an email GitHub does not know — and keying on login alone + // would then emit two trailers for them. + const seenEmails = new Set(); + + for (const entry of commits ?? []) { + const login = entry?.author?.login ?? null; + const gitName = entry?.commit?.author?.name ?? null; + const gitEmail = entry?.commit?.author?.email ?? null; + + // The PR author's own commits need no trailer — the squash is already + // theirs. Compared case-insensitively because GitHub logins are. + if (login && author && login.toLowerCase() === author) continue; + + // Bots author plenty of commits and crediting them is noise. + if (login && /\[bot\]$/.test(login)) continue; + if (!login && !gitName) continue; + + // A commit GitHub could not match to an account may still be the PR + // author's own — their git config carrying an email GitHub does not know. + // Without this they are listed as a co-author of themselves. + if (!login && author) { + const nameMatches = gitName && gitName.toLowerCase() === author; + const emailMatches = gitEmail && gitEmail.toLowerCase().startsWith(`${author}@`); + if (nameMatches || emailMatches) continue; + } + + // Prefer the GitHub identity, so the trailer links to a profile. Fall back + // to the raw git author for a commit GitHub could not match to an account. + const name = login ?? gitName; + const email = login ? noReplyEmail(login) : gitEmail; + if (!email) continue; + + // Keyed on identity, not on the rendered line. One person whose git config + // name changed across commits is still one person, and emitting them twice + // would put two trailers for the same contributor into the squash body. + const key = (login ?? gitEmail ?? name).toLowerCase(); + if (contributors.has(key)) continue; + const emailKey = (gitEmail ?? '').toLowerCase(); + if (emailKey && seenEmails.has(emailKey)) continue; + if (emailKey) seenEmails.add(emailKey); + + const displayName = gitName && login ? gitName : name; + contributors.set(key, { + trailer: `Co-Authored-By: ${displayName} <${email}>`, + name: displayName, + }); + } + + if (contributors.size === 0) return { passed: true, informational: [] }; + + const trailers = [...contributors.values()].map(c => c.trailer).sort(); + const names = [...new Set([...contributors.values()].map(c => c.name))].sort(); + const who = names.length === 1 ? names[0] : `${names.length} other contributors`; + + return { + passed: true, + informational: [ + `This branch carries commits by ${who}. Squash-merging drops that authorship unless ` + + 'the squash message carries their trailers, and nothing else will notice if it does not. ' + + 'Add to the squash body when merging:\n\n' + + trailers.map(line => ` ${line}`).join('\n'), + ], + }; +} + +if (process.argv[1] === fileURLToPath(import.meta.url)) { + const commits = JSON.parse(process.env.PR_COMMITS ?? '[]'); + const result = checkCoauthors(commits, process.env.PR_AUTHOR ?? ''); + console.log(JSON.stringify(result)); + process.exit(0); +} diff --git a/.github/scripts/run-quality-gates.mjs b/.github/scripts/run-quality-gates.mjs index fde29a1a33..31a1a12a00 100644 --- a/.github/scripts/run-quality-gates.mjs +++ b/.github/scripts/run-quality-gates.mjs @@ -17,6 +17,7 @@ import { checkTestCoverage } from './check-pr-test-coverage.mjs'; import { checkLockfile } from './check-pr-lockfile.mjs'; import { checkDependencies } from './check-pr-dependencies.mjs'; import { checkReleaseBootstrap } from './check-pr-release-bootstrap.mjs'; +import { checkCoauthors, fetchAllPullRequestCommits } from './check-pr-coauthors.mjs'; const COMMENT_SIGNATURE = '— commitperclip'; @@ -106,6 +107,17 @@ async function main() { fetchAllPullRequestFiles(ghFetch, GH_REPO, prNumber, GH_TOKEN), ]); + // Separate, and allowed to fail. The co-author note is informational: it + // cannot fail a PR by design, so it must not be able to fail the workflow by + // accident either. Sharing the Promise.all above would let one transient + // 5xx on this request take down every gate, including the ones that block. + let commits = []; + try { + commits = await fetchAllPullRequestCommits(ghFetch, GH_REPO, prNumber, GH_TOKEN); + } catch (error) { + console.error(`co-author lookup skipped: ${error.message}`); + } + const prBody = pr.body ?? ''; const author = PR_AUTHOR ?? pr.user.login; const branch = PR_BRANCH ?? pr.head.ref; @@ -122,6 +134,7 @@ async function main() { checkDependencies(files, GH_TOKEN, GH_REPO, prNumber, pr.base?.ref), checkReleaseBootstrap(files, GH_TOKEN, GH_REPO, prNumber, pr.base?.ref), ]); + const coauthorResult = checkCoauthors(commits, author); const allFailures = [ ...templateResult.failures, @@ -133,6 +146,7 @@ async function main() { const informational = [ ...(depsResult.informational ?? []), ...(bootstrapResult.informational ?? []), + ...coauthorResult.informational, ]; const allPassed = allFailures.length === 0; diff --git a/.github/scripts/tests/check-pr-coauthors.test.mjs b/.github/scripts/tests/check-pr-coauthors.test.mjs new file mode 100644 index 0000000000..8f33953238 --- /dev/null +++ b/.github/scripts/tests/check-pr-coauthors.test.mjs @@ -0,0 +1,179 @@ +import { test } from 'node:test'; +import assert from 'node:assert/strict'; +import { checkCoauthors, fetchAllPullRequestCommits } from '../check-pr-coauthors.mjs'; + +function commit(login, name = null, email = null) { + return { + author: login ? { login } : null, + commit: { author: { name: name ?? login, email: email ?? `${login}@users.noreply.github.com` } }, + }; +} + +test('checkCoauthors: says nothing when every commit is the PR author\'s own', () => { + const result = checkCoauthors( + [commit('tonio-alucema'), commit('tonio-alucema')], + 'tonio-alucema' + ); + + assert.equal(result.passed, true); + assert.deepEqual(result.informational, []); +}); + +test('checkCoauthors: hands over the trailer when the branch carries someone else\'s commit', () => { + // The case this exists for: a stale contributor PR rebased and landed by a + // maintainer. Squash-merging drops the contributor unless the squash body + // carries their trailer. + const result = checkCoauthors( + [commit('stubbi', 'Jannes Stubbemann'), commit('tonio-alucema')], + 'tonio-alucema' + ); + + assert.equal(result.informational.length, 1); + assert.match(result.informational[0], /Jannes Stubbemann/); + assert.match( + result.informational[0], + /Co-Authored-By: Jannes Stubbemann / + ); +}); + +test('checkCoauthors: never fails the PR, because the squash message does not exist yet', () => { + // Informational only. The author of the PR cannot satisfy this from the PR, + // so failing here would block work on something unfixable at that point. + const result = checkCoauthors([commit('stubbi')], 'tonio-alucema'); + + assert.equal(result.passed, true); +}); + +test('checkCoauthors: matches the PR author case-insensitively', () => { + // GitHub logins are case-insensitive, and PR_AUTHOR does not always arrive + // in the same case as the commit author login. + const result = checkCoauthors([commit('Tonio-Alucema')], 'tonio-alucema'); + + assert.deepEqual(result.informational, []); +}); + +test('checkCoauthors: ignores bots', () => { + const result = checkCoauthors( + [commit('github-actions[bot]'), commit('dependabot[bot]')], + 'tonio-alucema' + ); + + assert.deepEqual(result.informational, []); +}); + +test('checkCoauthors: lists each contributor once, however many commits they wrote', () => { + const result = checkCoauthors( + [commit('stubbi', 'Jannes Stubbemann'), commit('stubbi', 'Jannes Stubbemann')], + 'tonio-alucema' + ); + + const trailers = result.informational[0].match(/Co-Authored-By:/g) ?? []; + assert.equal(trailers.length, 1); +}); + +test('checkCoauthors: falls back to the raw git author when GitHub matched no account', () => { + // A commit authored with an email GitHub cannot resolve still deserves a + // trailer — that is precisely the identity most likely to be lost. + const result = checkCoauthors( + [{ author: null, commit: { author: { name: 'Ada Lovelace', email: 'ada@example.com' } } }], + 'tonio-alucema' + ); + + assert.match(result.informational[0], /Co-Authored-By: Ada Lovelace /); +}); + +test('checkCoauthors: skips an unattributable commit rather than emitting a broken trailer', () => { + const result = checkCoauthors( + [{ author: null, commit: { author: { name: 'Nameless', email: null } } }], + 'tonio-alucema' + ); + + assert.deepEqual(result.informational, []); +}); + +test('checkCoauthors: names the count rather than everyone when several contributed', () => { + const result = checkCoauthors( + [commit('stubbi', 'Jannes Stubbemann'), commit('elJayAdvisor', 'LJ')], + 'tonio-alucema' + ); + + assert.match(result.informational[0], /2 other contributors/); + assert.match(result.informational[0], /Jannes Stubbemann/); + assert.match(result.informational[0], /LJ/); +}); + +test('checkCoauthors: tolerates a PR with no commits', () => { + assert.deepEqual(checkCoauthors([], 'tonio-alucema').informational, []); + assert.deepEqual(checkCoauthors(undefined, 'tonio-alucema').informational, []); +}); + +test('fetchAllPullRequestCommits: pages until a short batch', async () => { + const seen = []; + const commits = await fetchAllPullRequestCommits(async (path) => { + seen.push(path); + if (path.endsWith('page=1')) return Array.from({ length: 100 }, () => commit('stubbi')); + return [commit('tonio-alucema')]; + }, 'paperclipai/paperclip', 9900, 'token'); + + assert.equal(commits.length, 101); + assert.equal(seen.length, 2); +}); + +test('fetchAllPullRequestCommits: stops at the API ceiling instead of looping', async () => { + // `/pulls/{n}/commits` caps at 250 and keeps returning full pages of nothing + // new past that. A branch that large is not what this gate is about, but it + // must not spin. + let calls = 0; + const commits = await fetchAllPullRequestCommits(async () => { + calls += 1; + return Array.from({ length: 100 }, () => commit('stubbi')); + }, 'paperclipai/paperclip', 9900, 'token'); + + assert.equal(calls, 3); + assert.equal(commits.length, 300); +}); + +test('checkCoauthors: counts one person once when their git name varies across commits', () => { + // People change their git config. Keying the dedup on the rendered trailer + // would put two lines for the same contributor into the squash body. + const result = checkCoauthors( + [commit('stubbi', 'Jannes Stubbemann'), commit('stubbi', 'J. Stubbemann')], + 'tonio-alucema' + ); + + const trailers = result.informational[0].match(/Co-Authored-By:/g) ?? []; + assert.equal(trailers.length, 1); + assert.doesNotMatch(result.informational[0], /other contributors/); +}); + +test('checkCoauthors: does not credit the PR author as a co-author of themselves', () => { + // Their own commit, authored with an email GitHub could not match to the + // account. Without the guard they appear in their own trailer list. + const byName = checkCoauthors( + [{ author: null, commit: { author: { name: 'tonio-alucema', email: 'tonio@example.com' } } }], + 'tonio-alucema' + ); + const byEmail = checkCoauthors( + [{ author: null, commit: { author: { name: 'Tonio', email: 'tonio-alucema@users.noreply.github.com' } } }], + 'tonio-alucema' + ); + + assert.deepEqual(byName.informational, []); + assert.deepEqual(byEmail.informational, []); +}); + +test('checkCoauthors: counts one person once when some commits matched their account and some did not', () => { + // The mixed case: GitHub resolved one commit to the login and left another + // unmatched, both carrying the same email. Keying on login alone emits two + // trailers for one contributor. + const result = checkCoauthors( + [ + commit('stubbi', 'Jannes Stubbemann', 'jannes@example.com'), + { author: null, commit: { author: { name: 'Jannes Stubbemann', email: 'jannes@example.com' } } }, + ], + 'tonio-alucema' + ); + + const trailers = result.informational[0].match(/Co-Authored-By:/g) ?? []; + assert.equal(trailers.length, 1); +}); diff --git a/.github/workflows/pr.yml b/.github/workflows/pr.yml index 591caf04ed..b1f4138959 100644 --- a/.github/workflows/pr.yml +++ b/.github/workflows/pr.yml @@ -57,6 +57,8 @@ jobs: - name: Test no-git-push check run: node --test ./scripts/check-no-git-push.test.mjs + - name: Test PR quality-gate scripts + run: node --test '.github/scripts/tests/*.test.mjs' - name: Test general-server shard partition run: node --test ./scripts/__tests__/run-vitest-stable-shard.test.mjs