CodeSampleX

Exemplo

express 5.2.1

Amostra verificada para npm express 5.2.1. O contrato rodou em node 22 · linux alpine/x64 · docker e passou: express() creates an application instance and…

sha256:9ab8b3fc8e0562fee4c6b35848021c4df71d8b332ee57bc250caa38421deb44c

Esta rede oferece uma coisa: uma amostra que compila. Ela a executou em um sandbox e guardou o recibo assinado. Não classifica nem garante nada — se o mesmo código compila onde você está, ela não mediu. Quantas chaves de assinatura distintas enviaram um recibo de contrato aprovado. Uma é só o autor; mais de uma significa que outra pessoa também o compilou. Uma chave é gerada por conta própria e não tem identidade registrada por trás, então conta chaves, não pessoas. MIT-0

Evidência de execução

O ambiente declarado e as execuções assinadas ficam separados, para você ver exatamente o que esta amostra executou e onde.

Base da evidência
Contrato assinado aprovado
Recibos de verificação
1
Chaves de assinatura que o compilaram
1
Ambiente declarado linux 24 · ubuntu · glibc 2.39 x64 npm

Ambientes das execuções de verificação

Ambiente Contrato Etapas Execução
node 22 · linux alpine/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1		 2026-08-20

Caso

HOW
Objetivo
verify pkg:npm/express@5.2.1
Pacotes
Criado
2026-08-20T13:48:38Z

Contrato

  1. express() creates an application instance and express.Router() creates modular route handlers
  2. nested router with mergeParams: true inherits and resolves parent path parameters across route hierarchies
  3. res.set() configures custom response headers, res.cookie() sets HttpOnly and SameSite cookie options, and res.status().json() delivers formatted JSON responses
  4. async route handlers returning rejected promises automatically propagate errors to Express error-handling middleware without unhandled rejections

Arquivos

  • PROMPT.md
  • csx.json
  • package-lock.json
  • package.json
  • spec.json
  • src/index.js
  • test/contract.mjs

Baixar o artefato de código-fonte (tar.gz)

Código-fonte

PROMPT.md
Clean-room public code sample — generation instructions

Write a brand-new, minimal, self-contained code sample in this clean-room directory.
Do not copy, paraphrase, or reference any existing project source. Work only from this spec.

A csx.json manifest scaffold already exists. Do not recreate it from memory. Preserve its case.goal, packages and symbols; fill its empty case.contract with exact assertions and correct its environment, commands and verifierAdapter for the files you generate.

Goal: verify pkg:npm/express@5.2.1
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/express@5.2.1

Rules:
  - One focused purpose; the smallest project that proves the goal.
  - Include a contract test (test/contract.*) that runs OFFLINE and exits 0 exactly when the goal behavior works.
  - Pin every dependency with a lockfile so resolution is reproducible.
  - No secrets, credentials, or tokens. No real URLs (only example.com or localhost). No absolute paths.
  - No personal names, emails, company names, or project identifiers of any kind.
  - No binaries and no generated output (node_modules, dist, target, venv, .git, .env).
  - Keep it under 200 files and 256KB packed.
csx.json
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package-lock.json
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package.json
{
  "name": "sample-express",
  "version": "1.0.0",
  "private": true,
  "description": "Clean-room verification of express",
  "main": "src/index.js",
  "license": "MIT-0",
  "dependencies": {
    "express": "5.2.1"
  }
}
spec.json
{
  "schemaVersion": 1,
  "goal": "verify pkg:npm/express@5.2.1",
  "kind": "HOW",
  "packages": [
    "pkg:npm/express@5.2.1"
  ]
}
src/index.js
const express = require('express');

/**
 * Creates and configures an Express application with async error handling,
 * nested router parameter merging, and standard response helpers.
 * @returns {import('express').Express}
 */
function createApp() {
  const app = express();

  // JSON parsing middleware
  app.use(express.json());

  // Nested router with mergeParams
  const parentRouter = express.Router();
  const childRouter = express.Router({ mergeParams: true });

  childRouter.get('/items/:itemId', (req, res) => {
    res.status(200).json({
      orgId: req.params.orgId,
      itemId: req.params.itemId
    });
  });

  parentRouter.use('/orgs/:orgId', childRouter);
  app.use('/api', parentRouter);

  // Response header and cookie demonstration
  app.get('/api/response-helpers', (req, res) => {
    res.set('X-Custom-Header', 'express-v5');
    res.cookie('auth_token', 'test-token-12345', {
      httpOnly: true,
      sameSite: 'strict',
      path: '/'
    });
    res.status(200).json({ success: true, message: 'Response helpers verified' });
  });

  // Async route handler that throws - testing native Express 5 Promise rejection handling
  app.get('/api/async-error', async (req, res) => {
    throw new Error('Async execution failed');
  });

  // Error-handling middleware
  app.use((err, req, res, next) => {
    res.status(500).json({
      error: true,
      message: err.message
    });
  });

  return app;
}

module.exports = {
  createApp,
  express
};
test/contract.mjs
import assert from 'node:assert';
import http from 'node:http';
import { createRequire } from 'node:module';

const require = createRequire(import.meta.url);
const { createApp, express } = require('../src/index.js');

// 1. Verify exports and types
assert.strictEqual(typeof express, 'function', 'express must be exported as a function');
assert.strictEqual(typeof express.Router, 'function', 'express.Router must be a function');
assert.strictEqual(typeof createApp, 'function', 'createApp must be a function');

const app = createApp();
assert.ok(app, 'app must be created');
assert.strictEqual(typeof app.listen, 'function', 'app.listen must be a function');

const server = http.createServer(app);

async function runContract() {
  await new Promise((resolve, reject) => {
    server.listen(0, '127.0.0.1', () => {
      resolve();
    });
    server.on('error', reject);
  });

  const address = server.address();
  const baseUrl = `http://127.0.0.1:${address.port}`;

  try {
    // 1. Verify nested router with mergeParams: true propagates parent route parameters
    const nestedRes = await fetch(`${baseUrl}/api/orgs/org-42/items/item-99`);
    assert.strictEqual(nestedRes.status, 200, 'Nested router should return 200');
    const nestedData = await nestedRes.json();
    assert.deepStrictEqual(nestedData, { orgId: 'org-42', itemId: 'item-99' }, 'Parent and child params should match');

    // 2. Verify response helpers (res.set, res.cookie, res.status, res.json)
    const helperRes = await fetch(`${baseUrl}/api/response-helpers`);
    assert.strictEqual(helperRes.status, 200, 'Response helpers should return 200');
    assert.strictEqual(helperRes.headers.get('x-custom-header'), 'express-v5', 'Custom header should match');
    const cookieHeader = helperRes.headers.get('set-cookie');
    assert.ok(cookieHeader && cookieHeader.includes('auth_token=test-token-12345'), 'Cookie header should contain auth_token');
    assert.ok(cookieHeader.toLowerCase().includes('httponly'), 'Cookie should be HttpOnly');
    assert.ok(cookieHeader.toLowerCase().includes('samesite=strict'), 'Cookie should have SameSite=Strict');
    const helperData = await helperRes.json();
    assert.deepStrictEqual(helperData, { success: true, message: 'Response helpers verified' });

    // 3. Verify Express 5 native async route handler rejection propagation to error middleware
    const asyncErrRes = await fetch(`${baseUrl}/api/async-error`);
    assert.strictEqual(asyncErrRes.status, 500, 'Async rejected error should be caught by error middleware with 500');
    const asyncErrData = await asyncErrRes.json();
    assert.deepStrictEqual(asyncErrData, { error: true, message: 'Async execution failed' }, 'Error middleware payload should match');

    console.log('Contract tests passed successfully.');
  } finally {
    await new Promise((resolve) => server.close(resolve));
  }
}

runContract().catch((err) => {
  console.error('Contract test failed:', err);
  process.exit(1);
});

Seeder de origem

anônimo