actions/slash-commands/main.js
Den Delimarsky 9fc2acf515
Fix: require('@actions/github') not resolvable from external main.js
PR #5 broke the action in production — the require() fails with
MODULE_NOT_FOUND because actions/github-script bundles @actions/github
into dist/index.js; it's not in node_modules and not resolvable from
a sibling require()'d file.

Fix: flip the architecture. github-script's 'github' client now uses
bot-token (GITHUB_TOKEN), so the single 'github' object serves all
user-visible operations. The PAT is passed via env (ORG_TOKEN) and
used ONLY for the team-membership call via github.request() with an
explicit authorization header override.

Side effect: PAT requirements shrink further. It now ONLY needs
Organization Members:read — no repo perms, no Actions:write. All
repo-level operations (including workflow dispatch) use GITHUB_TOKEN
with the workflow's permissions: block.
2026-03-11 20:52:21 +00:00

317 lines
12 KiB
JavaScript

// Handler for /lgtm, /hold, and /stageblog slash commands. Called by actions/github-script
// via `require(github.action_path + '/main.js')({ github, context, core })`.
// See action.yml for input wiring via env vars.
module.exports = async ({ github, context, core }) => {
const { owner, repo } = context.repo;
const approvedLabel = process.env.APPROVED_LABEL;
const holdLabel = process.env.HOLD_LABEL;
const alwaysAllowTeams = process.env.ALWAYS_ALLOW_TEAMS
.split(',').map(s => s.trim()).filter(Boolean);
const codeownersPath = process.env.CODEOWNERS_PATH;
const invalidateOnPush = process.env.INVALIDATE_ON_PUSH === 'true';
const submitReview = process.env.SUBMIT_REVIEW === 'true';
const reviewMarker = '<!-- slash-commands-lgtm -->';
// `github` is authed with bot-token (defaults to GITHUB_TOKEN) so comments,
// reactions, labels, and reviews show as github-actions[bot]. The PAT is
// passed separately and used ONLY for team-membership checks (read:org).
const orgToken = process.env.ORG_TOKEN;
function setResult(result, actor) {
core.setOutput('result', result);
core.setOutput('actor', actor || '');
core.info(`Result: ${result}${actor ? ` (actor: ${actor})` : ''}`);
}
// --- CODEOWNERS pattern → regex ---------------------------------
// Supports: leading-/ anchoring, trailing-/ directory match,
// `**` (any depth), `*` (single segment), `?`. No `!` negation.
function patternToRegex(pattern) {
let p = pattern;
const anchored = p.startsWith('/');
if (anchored) p = p.slice(1);
const dirMatch = p.endsWith('/');
if (dirMatch) p = p.slice(0, -1);
// Escape regex meta chars except our glob tokens * and ?
let re = p.replace(/[.+^${}()|[\]\\]/g, '\\$&');
// Handle globs. Use placeholders so single-* replacement doesn't
// catch ** sequences. `**/` = zero or more directories.
re = re.replace(/\*\*\//g, '\u0001');
re = re.replace(/\*\*/g, '\u0000');
re = re.replace(/\*/g, '[^/]*');
re = re.replace(/\?/g, '[^/]');
re = re.replace(/\u0001/g, '(?:.*/)?');
re = re.replace(/\u0000/g, '.*');
// Anchoring: leading `/` → match from repo root; otherwise
// match at any path depth (start or after a `/`).
const prefix = anchored ? '^' : '(^|/)';
// Trailing `/` → directory prefix (match anything under it).
// Otherwise must match to end of string.
const suffix = dirMatch ? '/.*$' : '$';
return new RegExp(prefix + re + suffix);
}
function parseCodeowners(content) {
const rules = [];
for (const raw of content.split('\n')) {
const line = raw.replace(/#.*$/, '').trim();
if (!line) continue;
const parts = line.split(/\s+/);
const pattern = parts[0];
const owners = parts.slice(1);
if (!owners.length) continue;
rules.push({ regex: patternToRegex(pattern), owners });
}
return rules;
}
function ownersForFile(rules, file) {
// Last match wins.
let owners = null;
for (const r of rules) {
if (r.regex.test(file)) owners = r.owners;
}
return owners || [];
}
// --- Auth helpers -----------------------------------------------
const teamMembershipCache = new Map();
async function isTeamMember(user, teamSlug) {
const key = `${teamSlug}:${user}`;
if (teamMembershipCache.has(key)) return teamMembershipCache.get(key);
try {
const { data } = await github.request(
'GET /orgs/{org}/teams/{team_slug}/memberships/{username}',
{
org: owner, team_slug: teamSlug, username: user,
headers: { authorization: `token ${orgToken}` },
},
);
const ok = data.state === 'active';
teamMembershipCache.set(key, ok);
return ok;
} catch (e) {
if (e.status === 404) {
teamMembershipCache.set(key, false);
return false;
}
// 403 here almost always means the token lacks read:org.
if (e.status === 403) {
core.warning(`Team membership check for @${owner}/${teamSlug} returned 403 — the provided github-token likely lacks read:org (Organization Members:read) scope. Treating as not-a-member.`);
teamMembershipCache.set(key, false);
return false;
}
throw e;
}
}
async function isAuthorized(user, pr) {
// 1. always-allow teams
for (const team of alwaysAllowTeams) {
if (await isTeamMember(user, team)) {
core.info(`@${user} authorized via always-allow team @${owner}/${team}`);
return true;
}
}
// 2. CODEOWNERS of the PR's changed files (from BASE ref)
let content;
try {
const { data } = await github.rest.repos.getContent({
owner, repo, path: codeownersPath, ref: pr.base.ref,
});
content = Buffer.from(data.content, data.encoding).toString('utf8');
} catch (e) {
if (e.status === 404) {
core.info(`No CODEOWNERS found at ${codeownersPath} on ${pr.base.ref}`);
return false;
}
throw e;
}
const rules = parseCodeowners(content);
const files = await github.paginate(github.rest.pulls.listFiles, {
owner, repo, pull_number: pr.number, per_page: 100,
});
const ownerSet = new Set();
for (const f of files) {
for (const o of ownersForFile(rules, f.filename)) ownerSet.add(o);
}
core.info(`CODEOWNERS for this PR's files: ${[...ownerSet].join(', ') || '(none)'}`);
for (const o of ownerSet) {
if (o.includes('/')) {
// @org/team — we require the org to match our repo's org
const [oOrg, oTeam] = o.replace(/^@/, '').split('/');
if (oOrg.toLowerCase() !== owner.toLowerCase()) continue;
if (await isTeamMember(user, oTeam)) {
core.info(`@${user} authorized via CODEOWNER team ${o}`);
return true;
}
} else {
// @user
if (o.replace(/^@/, '').toLowerCase() === user.toLowerCase()) {
core.info(`@${user} authorized via CODEOWNER user entry`);
return true;
}
}
}
return false;
}
// --- Label & review helpers -------------------------------------
async function addLabel(prNumber, label) {
await github.rest.issues.addLabels({
owner, repo, issue_number: prNumber, labels: [label],
});
}
async function removeLabel(prNumber, label) {
try {
await github.rest.issues.removeLabel({
owner, repo, issue_number: prNumber, name: label,
});
} catch (e) {
if (e.status !== 404) throw e;
}
}
async function react(commentId, content) {
await github.rest.reactions.createForIssueComment({
owner, repo, comment_id: commentId, content,
});
}
async function submitApproval(prNumber, onBehalfOf) {
await github.rest.pulls.createReview({
owner, repo, pull_number: prNumber, event: 'APPROVE',
body: `${reviewMarker}\nApproved on behalf of @${onBehalfOf} via \`/lgtm\`.`,
});
}
async function dismissBotApprovals(prNumber, reason) {
const reviews = await github.paginate(github.rest.pulls.listReviews, {
owner, repo, pull_number: prNumber, per_page: 100,
});
for (const r of reviews) {
if (r.state !== 'APPROVED') continue;
if (!r.body || !r.body.includes(reviewMarker)) continue;
try {
await github.rest.pulls.dismissReview({
owner, repo, pull_number: prNumber, review_id: r.id,
message: reason,
});
} catch (e) {
core.warning(`Failed to dismiss review ${r.id}: ${e.message}`);
}
}
}
// --- Dispatch ---------------------------------------------------
const ev = context.eventName;
// Invalidation on push
if (ev === 'pull_request_target' && context.payload.action === 'synchronize') {
if (!invalidateOnPush) return setResult('noop');
const pr = context.payload.pull_request;
const hasApproved = pr.labels.some(l => l.name === approvedLabel);
if (!hasApproved) return setResult('noop');
await removeLabel(pr.number, approvedLabel);
await dismissBotApprovals(pr.number, 'New commits pushed — approval invalidated.');
await github.rest.issues.createComment({
owner, repo, issue_number: pr.number,
body: `New commits were pushed — removed the \`${approvedLabel}\` label. Re-approve with \`/lgtm\`.`,
});
return setResult('invalidated');
}
// Comment commands
if (ev !== 'issue_comment') return setResult('noop');
if (!context.payload.issue.pull_request) return setResult('noop');
const commentBody = context.payload.comment.body || '';
const commentId = context.payload.comment.id;
const actor = context.payload.comment.user.login;
const firstLine = commentBody.split('\n')[0].trim();
const m = firstLine.match(/^\/(lgtm|hold|unhold|stageblog)\b\s*(cancel)?\s*$/i);
if (!m) return setResult('noop', actor);
const cmd = m[1].toLowerCase();
const cancel = !!m[2] || cmd === 'unhold';
const prNumber = context.payload.issue.number;
const { data: pr } = await github.rest.pulls.get({ owner, repo, pull_number: prNumber });
if (pr.state !== 'open') return setResult('noop', actor);
// Self-approval guard (only for /lgtm, not /hold)
if (cmd === 'lgtm' && !cancel && actor.toLowerCase() === pr.user.login.toLowerCase()) {
await react(commentId, '-1');
return setResult('self-lgtm-blocked', actor);
}
// Auth check (same rule for all commands)
if (!(await isAuthorized(actor, pr))) {
await react(commentId, '-1');
return setResult('unauthorized', actor);
}
// /stageblog — dispatch a caller-defined workflow with pinned head SHA
if (cmd === 'stageblog') {
const stageblogWorkflow = process.env.STAGEBLOG_WORKFLOW;
if (!stageblogWorkflow) {
await react(commentId, 'confused');
return setResult('stageblog-disabled', actor);
}
// cancel is meaningless here — just ignore silently
if (cancel) return setResult('noop', actor);
// Ack early — listFiles pagination + workflow dispatch can take a few
// seconds and the commenter otherwise gets no feedback until then.
await react(commentId, 'eyes');
// Gate: PR must touch blog paths
const blogRegexes = process.env.STAGEBLOG_PATHS
.split(',').map(s => s.trim()).filter(Boolean).map(patternToRegex);
const files = await github.paginate(github.rest.pulls.listFiles, {
owner, repo, pull_number: prNumber, per_page: 100,
});
const touchesBlog = files.some(f => blogRegexes.some(r => r.test(f.filename)));
if (!touchesBlog) {
await react(commentId, '-1');
await github.rest.issues.createComment({
owner, repo, issue_number: prNumber,
body: `\`/stageblog\` refused — this PR does not touch any blog paths (\`${process.env.STAGEBLOG_PATHS}\`).`,
});
return setResult('stageblog-not-blog', actor);
}
// Dispatch — pin head SHA at time of comment
const headSha = pr.head.sha;
await github.rest.actions.createWorkflowDispatch({
owner, repo, workflow_id: stageblogWorkflow, ref: pr.base.ref,
inputs: { pr_number: String(prNumber), head_sha: headSha },
});
await react(commentId, 'rocket');
await github.rest.issues.createComment({
owner, repo, issue_number: prNumber,
body: `Blog staging triggered by @${actor} for \`${headSha.slice(0, 7)}\`. Watch the [**${stageblogWorkflow}** workflow](../actions/workflows/${stageblogWorkflow}) for the preview link.`,
});
return setResult('stageblog-dispatched', actor);
}
// Execute
if (cmd === 'lgtm' && !cancel) {
await addLabel(prNumber, approvedLabel);
if (submitReview) await submitApproval(prNumber, actor);
await react(commentId, '+1');
return setResult('lgtm-added', actor);
}
if (cmd === 'lgtm' && cancel) {
await removeLabel(prNumber, approvedLabel);
await dismissBotApprovals(prNumber, `@${actor} cancelled approval via /lgtm cancel.`);
await react(commentId, '+1');
return setResult('lgtm-removed', actor);
}
if ((cmd === 'hold' && !cancel)) {
await addLabel(prNumber, holdLabel);
await react(commentId, '+1');
return setResult('hold-added', actor);
}
// /hold cancel or /unhold
await removeLabel(prNumber, holdLabel);
await react(commentId, '+1');
return setResult('hold-removed', actor);
};