feat(merge): gstack-merge regime-aware merge helper + tests

Pure regime logic in lib/merge.ts (detect/submit-plan/classify-land/handoff schema+validation) behind a thin bin/gstack-merge CLI (detect/submit/wait/ write-state/read-state). Supports none, GitHub native merge queue, and the trunk.io merge queue with a comment-first submit chain. 41 deterministic tests (30 unit + 11 CLI). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-18 07:40:09 +02:00 · 2026-05-31 09:13:16 -07:00
parent 9562ad4e70
commit e7741d9841
4 changed files with 1133 additions and 0 deletions
@@ -0,0 +1,131 @@
+// Deterministic end-to-end coverage of the bin/gstack-merge CLI (arg parsing,
+// file IO, and the lib/merge.ts wiring through the real binary). Free + fast —
+// no claude -p, no network. The submit/wait/classify *logic* is unit-tested in
+// gstack-merge.test.ts; this proves the executable plumbs it correctly and that
+// the handoff contract (write → consume, with null/stale/foreign rejection)
+// round-trips through the actual CLI surface /land and /land-and-deploy call.
+
+import { describe, test, expect, beforeEach, afterEach } from 'bun:test';
+import { spawnSync } from 'node:child_process';
+import { mkdtempSync, rmSync, mkdirSync, writeFileSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { join } from 'node:path';
+
+const BIN = join(import.meta.dir, '..', 'bin', 'gstack-merge');
+
+function runCli(args: string[], opts: { cwd?: string; home?: string } = {}) {
+  const r = spawnSync('bun', [BIN, ...args], {
+    encoding: 'utf-8',
+    cwd: opts.cwd || process.cwd(),
+    env: { ...process.env, ...(opts.home ? { HOME: opts.home } : {}) },
+    timeout: 30000,
+  });
+  return { code: r.status ?? 1, stdout: r.stdout || '', stderr: r.stderr || '' };
+}
+
+let tmp: string;
+beforeEach(() => { tmp = mkdtempSync(join(tmpdir(), 'gstack-merge-cli-')); });
+afterEach(() => { rmSync(tmp, { recursive: true, force: true }); });
+
+describe('gstack-merge CLI: detect', () => {
+  test('an explicit "Merge queue: trunk" config wins (no git/gh needed)', () => {
+    // A non-git temp dir: gh/git calls return nothing, so the config key is the
+    // only signal — exactly the precedence /land relies on.
+    writeFileSync(join(tmp, 'CLAUDE.md'), '# proj\n\n## Merge Configuration\n- Merge queue: trunk\n');
+    const r = runCli(['detect', '--base', 'main', '--json'], { cwd: tmp });
+    expect(r.code).toBe(0);
+    const out = JSON.parse(r.stdout.trim());
+    expect(out.regime).toBe('trunk');
+    expect(out.source).toBe('config');
+  });
+
+  test('config "Merge queue: github" is honored', () => {
+    writeFileSync(join(tmp, 'CLAUDE.md'), '## Merge Configuration\n- Merge queue: github\n');
+    const r = runCli(['detect', '--base', 'main', '--json'], { cwd: tmp });
+    expect(JSON.parse(r.stdout.trim()).regime).toBe('github');
+  });
+
+  test('no config + no signals → none', () => {
+    const r = runCli(['detect', '--base', 'main', '--json'], { cwd: tmp });
+    expect(r.code).toBe(0);
+    expect(JSON.parse(r.stdout.trim()).regime).toBe('none');
+  });
+});
+
+describe('gstack-merge CLI: handoff round-trip (write → consume)', () => {
+  const SLUG = 'acme-widget';
+  const REPO = 'acme/widget';
+
+  function seedHandoff(home: string, overrides: Record<string, unknown> = {}) {
+    const dir = join(home, '.gstack', 'projects', SLUG);
+    mkdirSync(dir, { recursive: true });
+    const state = {
+      schema_version: 1,
+      pr: 42,
+      sha: 'deadbeefcafe',
+      headRefOid: 'cafef00d',
+      base: 'main',
+      head_branch: 'feat/x',
+      repo: REPO,
+      regime: 'trunk',
+      ts: new Date().toISOString(),
+      ...overrides,
+    };
+    writeFileSync(join(dir, 'last-land.json'), JSON.stringify(state, null, 2));
+  }
+
+  test('read-state accepts a matching recent handoff and emits the SHA', () => {
+    seedHandoff(tmp);
+    const r = runCli(['read-state', '--slug', SLUG, '--pr', '42', '--repo', REPO], { home: tmp });
+    expect(r.code).toBe(0);
+    expect(r.stdout).toContain('LAND_SHA=deadbeefcafe');
+    expect(r.stdout).toContain('LAND_REGIME=trunk');
+  });
+
+  test('read-state rejects a handoff for a different PR (no cross-PR deploy)', () => {
+    seedHandoff(tmp);
+    const r = runCli(['read-state', '--slug', SLUG, '--pr', '99', '--repo', REPO], { home: tmp });
+    expect(r.code).toBe(1);
+    expect(r.stderr).toContain('READ_STATE_INVALID');
+  });
+
+  test('read-state rejects a handoff for a different repo', () => {
+    seedHandoff(tmp);
+    const r = runCli(['read-state', '--slug', SLUG, '--pr', '42', '--repo', 'other/repo'], { home: tmp });
+    expect(r.code).toBe(1);
+    expect(r.stderr).toContain('READ_STATE_INVALID');
+  });
+
+  test('read-state rejects a stale handoff', () => {
+    seedHandoff(tmp, { ts: '2020-01-01T00:00:00.000Z' });
+    const r = runCli(['read-state', '--slug', SLUG, '--pr', '42', '--repo', REPO], { home: tmp });
+    expect(r.code).toBe(1);
+    expect(r.stderr).toContain('READ_STATE_INVALID');
+  });
+
+  test('read-state rejects a handoff with an empty SHA (the null-SHA STOP)', () => {
+    seedHandoff(tmp, { sha: '' });
+    const r = runCli(['read-state', '--slug', SLUG, '--pr', '42', '--repo', REPO], { home: tmp });
+    expect(r.code).toBe(1);
+    expect(r.stderr).toContain('READ_STATE_INVALID');
+  });
+
+  test('read-state reports missing when there is no handoff at all', () => {
+    const r = runCli(['read-state', '--slug', 'nope', '--pr', '1', '--repo', REPO], { home: tmp });
+    expect(r.code).toBe(1);
+    expect(r.stderr).toContain('READ_STATE_INVALID');
+  });
+});
+
+describe('gstack-merge CLI: argument handling', () => {
+  test('unknown subcommand exits 2 with usage', () => {
+    const r = runCli(['frobnicate']);
+    expect(r.code).toBe(2);
+    expect(r.stderr).toContain('usage: gstack-merge');
+  });
+
+  test('submit without --pr exits 2', () => {
+    const r = runCli(['submit', '--regime', 'none']);
+    expect(r.code).toBe(2);
+  });
+});