Initial import from garrytan/gstack@026751e (main snapshot via local relay)

Source: https://github.com/garrytan/gstack/commit/026751e

test/readme-throughput.test.ts

@@ -0,0 +1,113 @@
+/**
+ * scripts/update-readme-throughput.ts + README anchor + CI pending-marker gate.
+ *
+ * Coverage:
+ * - Happy path: JSON present, anchor gets replaced with number + anchor preserved
+ * - Missing JSON: script writes PENDING marker, CI would reject
+ * - Invalid JSON: script errors, README untouched
+ * - CI gate: committed README must not contain PENDING marker
+ */
+import { describe, test, expect, beforeEach, afterEach } from 'bun:test';
+import * as fs from 'fs';
+import * as path from 'path';
+import * as os from 'os';
+import { spawnSync } from 'child_process';
+
+const ROOT = path.resolve(import.meta.dir, '..');
+const SCRIPT = path.join(ROOT, 'scripts', 'update-readme-throughput.ts');
+
+const ANCHOR = '<!-- GSTACK-THROUGHPUT-PLACEHOLDER -->';
+const PENDING = 'GSTACK-THROUGHPUT-PENDING';
+
+let tmpDir: string;
+let tmpReadme: string;
+let tmpJsonPath: string;
+
+beforeEach(() => {
+  tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'gstack-readme-test-'));
+  tmpReadme = path.join(tmpDir, 'README.md');
+  fs.mkdirSync(path.join(tmpDir, 'docs'), { recursive: true });
+  tmpJsonPath = path.join(tmpDir, 'docs', 'throughput-2013-vs-2026.json');
+});
+
+afterEach(() => {
+  fs.rmSync(tmpDir, { recursive: true, force: true });
+});
+
+function runScript(cwd: string): { stdout: string; stderr: string; status: number } {
+  const res = spawnSync('bun', ['run', SCRIPT], {
+    encoding: 'utf-8',
+    cwd,
+    env: { ...process.env },
+  });
+  return {
+    stdout: (res.stdout ?? '').trim(),
+    stderr: (res.stderr ?? '').trim(),
+    status: res.status ?? -1,
+  };
+}
+
+describe('update-readme-throughput script', () => {
+  test('happy path: JSON present → anchor replaced with number', () => {
+    fs.writeFileSync(tmpReadme, `gstack hero: ${ANCHOR} 2013 pro-rata.\n`);
+    fs.writeFileSync(tmpJsonPath, JSON.stringify({
+      multiples: { logical_lines_added: 12.3 },
+    }));
+
+    const result = runScript(tmpDir);
+    expect(result.status).toBe(0);
+
+    const updated = fs.readFileSync(tmpReadme, 'utf-8');
+    expect(updated).toContain('12.3×');
+    expect(updated).toContain(ANCHOR); // anchor stays for next run
+    expect(updated).not.toContain(PENDING);
+  });
+
+  test('missing JSON: PENDING marker written (CI rejects)', () => {
+    fs.writeFileSync(tmpReadme, `gstack hero: ${ANCHOR} 2013 pro-rata.\n`);
+    // No JSON written
+
+    const result = runScript(tmpDir);
+    expect(result.status).toBe(0);
+
+    const updated = fs.readFileSync(tmpReadme, 'utf-8');
+    expect(updated).toContain(PENDING);
+    expect(updated).toContain(ANCHOR); // anchor preserved for next run
+  });
+
+  test('JSON with null multiple: PENDING marker written (honest missing state)', () => {
+    fs.writeFileSync(tmpReadme, `gstack hero: ${ANCHOR} 2013 pro-rata.\n`);
+    fs.writeFileSync(tmpJsonPath, JSON.stringify({
+      multiples: { logical_lines_added: null },
+    }));
+
+    const result = runScript(tmpDir);
+    expect(result.status).toBe(0);
+
+    const updated = fs.readFileSync(tmpReadme, 'utf-8');
+    expect(updated).toContain(PENDING);
+    expect(updated).not.toMatch(/null×/);
+  });
+
+  test('anchor already replaced: script is a no-op', () => {
+    fs.writeFileSync(tmpReadme, 'gstack hero: 7.0× already set.\n');
+    // No anchor in README → nothing to replace
+
+    const result = runScript(tmpDir);
+    expect(result.status).toBe(0);
+
+    const updated = fs.readFileSync(tmpReadme, 'utf-8');
+    expect(updated).toBe('gstack hero: 7.0× already set.\n');
+  });
+});
+
+describe('CI gate: committed README must not contain PENDING marker', () => {
+  // This is the core reason the PENDING marker exists. A commit that lands
+  // the README with the pending string means the build didn't run.
+  test('real README.md does not contain GSTACK-THROUGHPUT-PENDING', () => {
+    const readmePath = path.join(ROOT, 'README.md');
+    if (!fs.existsSync(readmePath)) return; // Fresh clone edge-case
+    const content = fs.readFileSync(readmePath, 'utf-8');
+    expect(content).not.toContain(PENDING);
+  });
+});