als-send-file/tests/mw.test.js

file serving with advanced options for caching, headers, and error handling, compatible with Express middleware.

const { describe, it, before, after, beforeEach } = require('node:test');
const assert = require('node:assert');
const http = require('http');
const port = 22222;
const baseUrl = `http://localhost:${port}/`;
const mwFileHandler = require('../lib/mw');
const httpErrHandler = (res, code, msg) => { res.writeHead(code); res.end(msg); };
const { join } = require('path');
const root = join(__dirname, '..');
const { writeFileSync, unlinkSync } = require('node:fs');

const mw = mwFileHandler(root, httpErrHandler)
const server = http.createServer((req, res) => mw(req, res, async () => {
   const { search, pathname } = new URL(req.url, 'http://some.com');
   const options = {};
   search.replace('?', '').split('&').forEach(val => {
      let [k, v] = val.split('=');
      if (v === 'true') v = true
      if (k) options[k] = v;
   });
   res.sendFile(pathname, options)
}));

async function request(url, headers = {}, method = 'GET') {
   const response = await fetch(`${baseUrl}${url}`, { method, headers });
   const text = await response.text();
   return [response.status, text, response.headers, response];
}

describe('fileHandler Tests', () => {
   const filename = 'test-file.txt'
   const testFilePath = join(root, filename);
   before(async () => {
      await new Promise(r => setTimeout(r, 1000))
      writeFileSync(testFilePath, 'Hello from test-file.txt');
      server.listen(port, () => { console.log(`Server running on http://localhost:${port}`); });
   });
   after(() => {
      unlinkSync(testFilePath);
      server.close();
   });

   it('should return 404 if file not found', async () => {
      const [status, text] = await request('nonexistent-file.txt');
      assert.strictEqual(status, 404);
      assert.strictEqual(text, 'File nonexistent-file.txt not found');
   });

   it('should serve a file successfully with combined default and request-specific options', async () => {
      const [status, text, headers] = await request(filename + '?download=true&charset=utf-8');
      assert.strictEqual(status, 200);
      assert.strictEqual(text, 'Hello from test-file.txt');
      assert.strictEqual(headers.get('content-disposition'), 'attachment; filename="test-file.txt"');
      assert.strictEqual(headers.get('content-type'), 'text/plain; charset=utf-8');
   });

   it('should respect no-cache directive when specified', async () => {
      const [status, , headers] = await request(filename + '?noCache=true');
      assert.strictEqual(headers.get('cache-control'), 'no-cache');
   });
});