feat: add storage path helpers

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

test/storage.test.js

@@ -0,0 +1,52 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import fs from 'node:fs/promises';
+import path from 'node:path';
+import os from 'node:os';
+import { ensureStorageDirs, uploadPath, outputPath, deleteIfExists } from '../src/storage.js';
+
+let tmpDir;
+let config;
+
+beforeEach(async () => {
+  tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), 'converter-storage-'));
+  config = { storageDir: tmpDir };
+});
+
+afterEach(async () => {
+  await fs.rm(tmpDir, { recursive: true, force: true });
+});
+
+describe('storage', () => {
+  it('creates uploads and outputs directories', async () => {
+    await ensureStorageDirs(config);
+
+    const uploadsStat = await fs.stat(path.join(tmpDir, 'uploads'));
+    const outputsStat = await fs.stat(path.join(tmpDir, 'outputs'));
+
+    expect(uploadsStat.isDirectory()).toBe(true);
+    expect(outputsStat.isDirectory()).toBe(true);
+  });
+
+  it('builds upload and output paths as <uuid>.<ext>', () => {
+    const id = '11111111-1111-4111-8111-111111111111';
+
+    expect(uploadPath(config, id, 'png')).toBe(path.join(tmpDir, 'uploads', `${id}.png`));
+    expect(outputPath(config, id, 'pdf')).toBe(path.join(tmpDir, 'outputs', `${id}.pdf`));
+  });
+
+  it('deletes an existing file', async () => {
+    await ensureStorageDirs(config);
+    const filePath = uploadPath(config, 'file-to-delete', 'txt');
+    await fs.writeFile(filePath, 'content');
+
+    await deleteIfExists(filePath);
+
+    await expect(fs.stat(filePath)).rejects.toThrow();
+  });
+
+  it('does not throw when deleting a missing file', async () => {
+    const filePath = uploadPath(config, 'does-not-exist', 'txt');
+
+    await expect(deleteIfExists(filePath)).resolves.toBeUndefined();
+  });
+});