gstack/bin/gstack-lane-check

#!/usr/bin/env bun
/**
 * gstack-lane-check — planned files versus in-flight lanes (plan E2).
 *
 *   gstack-lane-check --planned <path|glob>[,...] [--planned-file <file>] [--branch <name>]... [--pr <n>]... [--base <ref>] [--json]
 *
 * Diffs each in-flight branch or pull request against its merge base with the
 * base branch and prints one `LANE_CONFLICT:` line per planned file it already
 * changes (PR number, branch, hunk count), then `LANE_CHECK: clear | conflicts | unresolved`.
 * Exit 0 clear, 1 conflicts, 3 when a lane could not be resolved and nothing conflicts.
 * Logic: lib/lane-ownership.ts. Codes: LANE_CONFLICT, LANE_REF_UNAVAILABLE (lib/result-codes.ts).
 */
import { spawnSync } from 'node:child_process';
import * as fs from 'node:fs';
import { EXIT, exitTableHelp } from '../lib/headless-artifacts';
import { laneCheck, renderLaneCheck } from '../lib/lane-ownership';
import { resultLine } from '../lib/result-codes';

const HELP = `gstack-lane-check — one owner per file across in-flight lanes

  --planned <p,p>        files or globs this lane plans to touch (repeatable; \`lib/**\` and \`*.ts\` wildcards)
  --planned-file <file>  one planned path per line (# comments allowed)
  --branch <name>        an in-flight branch (fetched: origin/<name> or local)
  --pr <n>               an in-flight pull request; its head branch comes from \`gh pr view\`
  --base <ref>           the base to diff against (default origin/HEAD, else origin/main)
  --json                 the whole check as one JSON object

${exitTableHelp()}`;

function main(argv: string[]): number {
  if (argv.includes('--help') || argv.includes('-h')) { process.stdout.write(HELP + '\n'); return EXIT.ok; }
  const planned: string[] = []; const branches: string[] = []; const prs: number[] = [];
  let base: string | undefined;
  for (let i = 0; i < argv.length; i++) {
    const a = argv[i]!;
    if (a === '--planned') planned.push(...(argv[++i] ?? '').split(','));
    else if (a === '--planned-file') {
      const file = argv[++i];
      if (!file || !fs.existsSync(file)) { process.stderr.write(`gstack-lane-check: --planned-file ${file ?? ''} not found\n`); return EXIT.usage; }
      planned.push(...fs.readFileSync(file, 'utf8').split('\n').map(l => l.replace(/#.*$/, '').trim()).filter(Boolean));
    }
    else if (a === '--branch') branches.push(argv[++i] ?? '');
    else if (a === '--pr') { const n = Number(argv[++i]); if (!Number.isInteger(n) || n <= 0) { process.stderr.write('gstack-lane-check: --pr needs a positive number\n'); return EXIT.usage; } prs.push(n); }
    else if (a === '--base') base = argv[++i];
    else if (a !== '--json') { process.stderr.write(`gstack-lane-check: unknown argument ${a}\n${HELP}\n`); return EXIT.usage; }
  }
  if (planned.filter(Boolean).length === 0) { process.stderr.write(`gstack-lane-check: --planned or --planned-file is required\n${HELP}\n`); return EXIT.usage; }
  if (branches.filter(Boolean).length === 0 && prs.length === 0) { process.stderr.write(`gstack-lane-check: name at least one --branch or --pr\n${HELP}\n`); return EXIT.usage; }
  const root = spawnSync('git', ['rev-parse', '--show-toplevel'], { encoding: 'utf8', timeout: 15_000 });
  if (root.status !== 0) { process.stderr.write('gstack-lane-check: not inside a git repository\n'); return EXIT.usage; }
  const check = laneCheck({ cwd: root.stdout.trim(), planned, branches: branches.filter(Boolean), prs, base });
  if (argv.includes('--json')) process.stdout.write(JSON.stringify(check) + '\n');
  else process.stdout.write(renderLaneCheck(check));
  for (const lane of check.unresolved) process.stderr.write(resultLine('gstack-lane-check', 'LANE_REF_UNAVAILABLE', lane.pr !== null ? `PR #${lane.pr}` : lane.branch) + '\n');
  if (check.intersections.length) {
    process.stderr.write(resultLine('gstack-lane-check', 'LANE_CONFLICT', `${check.intersections.length} planned file(s) already in flight`) + '\n');
    return EXIT.fail;
  }
  return check.unresolved.length ? EXIT.refused : EXIT.ok;
}

process.exitCode = main(process.argv.slice(2));