1 files changed, 90 insertions, 0 deletions
diff --git a/scripts/docs/preview.integration.test.ts b/scripts/docs/preview.integration.test.ts
new file mode 100644
index 00000000..74e54957
--- /dev/null
+++ b/scripts/docs/preview.integration.test.ts
@@ -0,0 +1,90 @@
+import { afterEach, describe, expect, test } from 'bun:test';
+import { execFileSync } from 'node:child_process';
+import { mkdtemp, mkdir, readFile, rm, writeFile } from 'node:fs/promises';
+import { join, resolve } from 'node:path';
+import { tmpdir } from 'node:os';
+
+const script = resolve(import.meta.dir, 'preview.mjs');
+const temporaryDirectories: string[] = [];
+
+afterEach(async () => {
+  await Promise.all(
+    temporaryDirectories.splice(0).map((path) => rm(path, { recursive: true, force: true })),
+  );
+});
+
+describe('preview documentation snapshots', () => {
+  test('snapshots and validates the selected commit exactly', async () => {
+    const root = await fixture();
+    const commit = git(root, ['rev-parse', 'HEAD']).trim();
+    await write(root, 'docs/preview/website/stale.mdx', 'stale\n');
+    await writeManifest(root, commit);
+
+    runScript(root, ['snapshot', commit]);
+    runScript(root, ['check']);
+
+    expect(await read(root, 'docs/preview/website/src/content/docs/index.mdx')).toBe(
+      'selected preview\n',
+    );
+    await expect(read(root, 'docs/preview/website/stale.mdx')).rejects.toThrow();
+  });
+
+  test('rejects snapshot drift', async () => {
+    const root = await fixture();
+    const commit = git(root, ['rev-parse', 'HEAD']).trim();
+    await writeManifest(root, commit);
+    runScript(root, ['snapshot', commit]);
+    await write(root, 'docs/preview/website/src/content/docs/index.mdx', 'changed\n');
+
+    expect(() => runScript(root, ['check'])).toThrow();
+  });
+});
+
+async function fixture() {
+  const root = await mkdtemp(join(tmpdir(), 'herdr-preview-docs-'));
+  temporaryDirectories.push(root);
+  await write(root, 'docs/next/website/src/content/docs/index.mdx', 'selected preview\n');
+  await write(root, 'docs/next/website/src/data/config-reference.json', '{"preview":true}\n');
+  git(root, ['init', '-q']);
+  git(root, ['config', 'user.email', 'test@example.com']);
+  git(root, ['config', 'user.name', 'Test']);
+  git(root, ['add', '.']);
+  git(root, ['commit', '-qm', 'preview fixture']);
+  return root;
+}
+
+async function writeManifest(root: string, commit: string) {
+  await write(
+    root,
+    'distribution/preview.json',
+    `${JSON.stringify({
+      schema_version: 1,
+      channel: 'preview',
+      build_id: 'test-build',
+      commit,
+      builds: { 'test-build': { commit, tag: 'preview-test-build' } },
+    })}\n`,
+  );
+}
+
+async function write(root: string, path: string, content: string) {
+  const destination = resolve(root, path);
+  await mkdir(resolve(destination, '..'), { recursive: true });
+  await writeFile(destination, content, 'utf8');
+}
+
+async function read(root: string, path: string) {
+  return readFile(resolve(root, path), 'utf8');
+}
+
+function git(root: string, args: string[]) {
+  return execFileSync('git', args, { cwd: root, encoding: 'utf8', stdio: 'pipe' });
+}
+
+function runScript(root: string, args: string[]) {
+  execFileSync('node', [script, ...args], {
+    cwd: root,
+    env: { ...process.env, HERDR_DOCS_REPO_ROOT: root },
+    stdio: 'pipe',
+  });
+}