CodeSampleX

Пример

express 5.1.0: urlencoded

Проверенный пример — npm express 5.1.0: urlencoded. Контракт выполнен на node 22 · linux alpine/x64 · docker и пройден: express.urlencoded({ extended: false…

sha256:6315d6c03276ac54cf592b240be3e3b34102e99c511c9e39ee783c2aaebf066f

Эта сеть предлагает одно: образец, который собирается. Она запустила его в песочнице и сохранила подписанную квитанцию. Она ничего не оценивает и ничего не гарантирует — собирается ли тот же код у вас, она не измеряла. Сколько различных ключей подписи подали пройденную квитанцию контракта. Один — только автор; больше одного — значит, кто-то ещё тоже собрал. Ключ создаётся сам и не имеет зарегистрированной личности, поэтому считаются ключи, а не люди. MIT-0

Свидетельства выполнения

Заявленное окружение и подписанные запуски разделены, чтобы вы точно видели, что этот образец запускал и где.

Основа свидетельства
Подписанный контракт пройден
Квитанции проверки
1
Ключи подписи, собравшие его
1
Заявленная среда linux 24 · ubuntu · glibc 2.39 x64 npm

Среды запусков проверки

Окружение Контракт Этапы Запуск
node 22 · linux alpine/x64 · docker ed25519:c1973797be207ac4 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1node:22-alpine@sha256:c610fcdfb1d5…		 2026-08-23

Кейс

HOW
Цель
verify express.urlencoded in pkg:npm/express@5.1.0
Пакеты
Символы
  • express.urlencoded
Создан
2026-08-23T04:36:14Z

Контракт

  1. express.urlencoded({ extended: false }) parses flat URL-encoded form data into req.body key-value pairs
  2. express.urlencoded({ extended: true }) parses nested URL-encoded form data into nested objects and arrays
  3. express.urlencoded({ limit }) rejects payloads exceeding the byte limit with a 413 entity.too.large status
  4. express.urlencoded() ignores requests with unmatched Content-Type headers leaving req.body untouched
  5. express.urlencoded() parses an empty URL-encoded request body into an empty object
  6. express.urlencoded({ type }) parses URL-encoded bodies matching a custom Content-Type header

Файлы

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

Скачать артефакт с исходным кодом (tar.gz)

Исходный код

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 express.urlencoded in pkg:npm/express@5.1.0
Kind: HOW

Use EXACTLY these public packages and versions:
  - pkg:npm/express@5.1.0
Demonstrate these symbols/APIs:
  - express.urlencoded

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
{"case":{"caseId":"case:sha256:2b46866212dbcec29c59916486957e651bd89380e559606157df3bcc24700aa8","contract":["express.urlencoded({ extended: false }) parses flat URL-encoded form data into req.body key-value pairs","express.urlencoded({ extended: true }) parses nested URL-encoded form data into nested objects and arrays","express.urlencoded({ limit }) rejects payloads exceeding the byte limit with a 413 entity.too.large status","express.urlencoded() ignores requests with unmatched Content-Type headers leaving req.body untouched","express.urlencoded() parses an empty URL-encoded request body into an empty object","express.urlencoded({ type }) parses URL-encoded bodies matching a custom Content-Type header"],"goal":"verify express.urlencoded in pkg:npm/express@5.1.0","kind":"HOW","packages":["pkg:npm/express@5.1.0"],"schemaVersion":1,"symbols":["express.urlencoded"]},"contractCommand":["node","test/contract.mjs"],"environment":{"arch":"x64","distro":"ubuntu","ecosystem":"npm","libc":"glibc","libcVersion":"2.39","os":"linux","osVersionBucket":"24","packageManager":"npm","schemaVersion":1},"license":"MIT-0","packages":["pkg:npm/express@5.1.0"],"schemaVersion":1,"subject":"pkg:npm/express@5.1.0","symbols":["express.urlencoded"],"verifierAdapter":"node-typescript@1"}
package-lock.json
{
  "name": "sample-express-urlencoded",
  "version": "1.0.0",
  "lockfileVersion": 3,
  "requires": true,
  "packages": {
    "": {
      "name": "sample-express-urlencoded",
      "version": "1.0.0",
      "dependencies": {
        "express": "5.1.0"
      }
    },
    "node_modules/accepts": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/accepts/-/accepts-2.0.0.tgz",
      "integrity": "sha512-5cvg6CtKwfgdmVqY1WIiXKc3Q1bkRqGLi+2W/6ao+6Y7gu/RCwRuAhGEzh5B4KlszSuTLgZYuqFqo5bImjNKng==",
      "license": "MIT",
      "dependencies": {
        "mime-types": "^3.0.0",
        "negotiator": "^1.0.0"
      },
      "engines": {
        "node": ">= 0.6"
      }
    },
    "node_modules/body-parser": {
      "version": "2.3.0",
      "resolved": "https://registry.npmjs.org/body-parser/-/body-parser-2.3.0.tgz",
      "integrity": "sha512-2cGmJupaNgg+QUwVLAucDuWuoMZ6EX9iHDRswZ5lsNYEmwPaRknMPCLZz07yTzVq/83p4o/wzbDZbBrTvGGTIw==",
      "license": "MIT",
      "dependencies": {
        "bytes": "^3.1.2",
        "content-type": "^2.0.0",
        "debug": "^4.4.3",
        "http-errors": "^2.0.1",
        "iconv-lite": "^0.7.2",
        "on-finished": "^2.4.1",
        "qs": "^6.15.2",
        "raw-body": "^3.0.2",
        "type-is": "^2.1.0"
      },
      "engines": {
        "node": ">=18"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/body-parser/node_modules/content-type": {
      "version": "2.1.0",
      "resolved": "https://registry.npmjs.org/content-type/-/content-type-2.1.0.tgz",
      "integrity": "sha512-mj7UPXE0jaqaOsukNZRUEfEi2AcL7C/vwmwcHV0O97eO1E1pxBZuyjlZrx5seTaNBg1U6+o35wpa35Qfcc+7ag==",
      "license": "MIT",
      "engines": {
        "node": ">=18"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/bytes": {
      "version": "3.1.2",
      "resolved": "https://registry.npmjs.org/bytes/-/bytes-3.1.2.tgz",
      "integrity": "sha512-/Nf7TyzTx6S3yRJObOAV7956r8cr2+Oj8AC5dt8wSP3BQAoeX58NoHyCU8P8zGkNXStjTSi6fzO6F0pBdcYbEg==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.8"
      }
    },
    "node_modules/call-bind-apply-helpers": {
      "version": "1.0.2",
      "resolved": "https://registry.npmjs.org/call-bind-apply-helpers/-/call-bind-apply-helpers-1.0.2.tgz",
      "integrity": "sha512-Sp1ablJ0ivDkSzjcaJdxEunN5/XvksFJ2sMBFfq6x0ryhQV/2b/KwFe21cMpmHtPOSij8K99/wSfoEuTObmuMQ==",
      "license": "MIT",
      "dependencies": {
        "es-errors": "^1.3.0",
        "function-bind": "^1.1.2"
      },
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/call-bound": {
      "version": "1.0.4",
      "resolved": "https://registry.npmjs.org/call-bound/-/call-bound-1.0.4.tgz",
      "integrity": "sha512-+ys997U96po4Kx/ABpBCqhA9EuxJaQWDQg7295H4hBphv3IZg0boBKuwYpt4YXp6MZ5AmZQnU/tyMTlRpaSejg==",
      "license": "MIT",
      "dependencies": {
        "call-bind-apply-helpers": "^1.0.2",
        "get-intrinsic": "^1.3.0"
      },
      "engines": {
        "node": ">= 0.4"
      },
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    },
    "node_modules/content-disposition": {
      "version": "1.1.0",
      "resolved": "https://registry.npmjs.org/content-disposition/-/content-disposition-1.1.0.tgz",
      "integrity": "sha512-5jRCH9Z/+DRP7rkvY83B+yGIGX96OYdJmzngqnw2SBSxqCFPd0w2km3s5iawpGX8krnwSGmF0FW5Nhr0Hfai3g==",
      "license": "MIT",
      "engines": {
        "node": ">=18"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/content-type": {
      "version": "1.0.5",
      "resolved": "https://registry.npmjs.org/content-type/-/content-type-1.0.5.tgz",
      "integrity": "sha512-nTjqfcBFEipKdXCv4YDQWCfmcLZKm81ldF0pAopTvyrFGVbcR6P/VAAd5G7N+0tTr8QqiU0tFadD6FK4NtJwOA==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.6"
      }
    },
    "node_modules/cookie": {
      "version": "0.7.2",
      "resolved": "https://registry.npmjs.org/cookie/-/cookie-0.7.2.tgz",
      "integrity": "sha512-yki5XnKuf750l50uGTllt6kKILY4nQ1eNIQatoXEByZ5dWgnKqbnqmTrBE5B4N7lrMJKQ2ytWMiTO2o0v6Ew/w==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.6"
      }
    },
    "node_modules/cookie-signature": {
      "version": "1.2.2",
      "resolved": "https://registry.npmjs.org/cookie-signature/-/cookie-signature-1.2.2.tgz",
      "integrity": "sha512-D76uU73ulSXrD1UXF4KE2TMxVVwhsnCgfAyTg9k8P6KGZjlXKrOLe4dJQKI3Bxi5wjesZoFXJWElNWBjPZMbhg==",
      "license": "MIT",
      "engines": {
        "node": ">=6.6.0"
      }
    },
    "node_modules/debug": {
      "version": "4.4.3",
      "resolved": "https://registry.npmjs.org/debug/-/debug-4.4.3.tgz",
      "integrity": "sha512-RGwwWnwQvkVfavKVt22FGLw+xYSdzARwm0ru6DhTVA3umU5hZc28V3kO4stgYryrTlLpuvgI9GiijltAjNbcqA==",
      "license": "MIT",
      "dependencies": {
        "ms": "^2.1.3"
      },
      "engines": {
        "node": ">=6.0"
      },
      "peerDependenciesMeta": {
        "supports-color": {
          "optional": true
        }
      }
    },
    "node_modules/depd": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/depd/-/depd-2.0.0.tgz",
      "integrity": "sha512-g7nH6P6dyDioJogAAGprGpCtVImJhpPk/roCzdb3fIh61/s/nPsfR6onyMwkCAR/OlC3yBC0lESvUoQEAssIrw==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.8"
      }
    },
    "node_modules/dunder-proto": {
      "version": "1.0.1",
      "resolved": "https://registry.npmjs.org/dunder-proto/-/dunder-proto-1.0.1.tgz",
      "integrity": "sha512-KIN/nDJBQRcXw0MLVhZE9iQHmG68qAVIBg9CqmUYjmQIhgij9U5MFvrqkUL5FbtyyzZuOeOt0zdeRe4UY7ct+A==",
      "license": "MIT",
      "dependencies": {
        "call-bind-apply-helpers": "^1.0.1",
        "es-errors": "^1.3.0",
        "gopd": "^1.2.0"
      },
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/ee-first": {
      "version": "1.1.1",
      "resolved": "https://registry.npmjs.org/ee-first/-/ee-first-1.1.1.tgz",
      "integrity": "sha512-WMwm9LhRUo+WUaRN+vRuETqG89IgZphVSNkdFgeb6sS/E4OrDIN7t48CAewSHXc6C8lefD8KKfr5vY61brQlow==",
      "license": "MIT"
    },
    "node_modules/encodeurl": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/encodeurl/-/encodeurl-2.0.0.tgz",
      "integrity": "sha512-Q0n9HRi4m6JuGIV1eFlmvJB7ZEVxu93IrMyiMsGC0lrMJMWzRgx6WGquyfQgZVb31vhGgXnfmPNNXmxnOkRBrg==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.8"
      }
    },
    "node_modules/es-define-property": {
      "version": "1.0.1",
      "resolved": "https://registry.npmjs.org/es-define-property/-/es-define-property-1.0.1.tgz",
      "integrity": "sha512-e3nRfgfUZ4rNGL232gUgX06QNyyez04KdjFrF+LTRoOXmrOgFKDg4BCdsjW8EnT69eqdYGmRpJwiPVYNrCaW3g==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/es-errors": {
      "version": "1.3.0",
      "resolved": "https://registry.npmjs.org/es-errors/-/es-errors-1.3.0.tgz",
      "integrity": "sha512-Zf5H2Kxt2xjTvbJvP2ZWLEICxA6j+hAmMzIlypy4xcBg1vKVnx89Wy0GbS+kf5cwCVFFzdCFh2XSCFNULS6csw==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/es-object-atoms": {
      "version": "1.1.2",
      "resolved": "https://registry.npmjs.org/es-object-atoms/-/es-object-atoms-1.1.2.tgz",
      "integrity": "sha512-HWcBoN6NileqtSydK2FqHbS/LoDd2pqrnQHLyJzBj4kOp/ky2MWMN694xOfkK8/SnUsW2DH7EfyVlydKCsm1Zw==",
      "license": "MIT",
      "dependencies": {
        "es-errors": "^1.3.0"
      },
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/escape-html": {
      "version": "1.0.3",
      "resolved": "https://registry.npmjs.org/escape-html/-/escape-html-1.0.3.tgz",
      "integrity": "sha512-NiSupZ4OeuGwr68lGIeym/ksIZMJodUGOSCZ/FSnTxcrekbvqrgdUxlJOMpijaKZVjAJrWrGs/6Jy8OMuyj9ow==",
      "license": "MIT"
    },
    "node_modules/etag": {
      "version": "1.8.1",
      "resolved": "https://registry.npmjs.org/etag/-/etag-1.8.1.tgz",
      "integrity": "sha512-aIL5Fx7mawVa300al2BnEE4iNvo1qETxLrPI/o05L7z6go7fCw1J6EQmbK4FmJ2AS7kgVF/KEZWufBfdClMcPg==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.6"
      }
    },
    "node_modules/express": {
      "version": "5.1.0",
      "resolved": "https://registry.npmjs.org/express/-/express-5.1.0.tgz",
      "integrity": "sha512-DT9ck5YIRU+8GYzzU5kT3eHGA5iL+1Zd0EutOmTE9Dtk+Tvuzd23VBU+ec7HPNSTxXYO55gPV/hq4pSBJDjFpA==",
      "license": "MIT",
      "dependencies": {
        "accepts": "^2.0.0",
        "body-parser": "^2.2.0",
        "content-disposition": "^1.0.0",
        "content-type": "^1.0.5",
        "cookie": "^0.7.1",
        "cookie-signature": "^1.2.1",
        "debug": "^4.4.0",
        "encodeurl": "^2.0.0",
        "escape-html": "^1.0.3",
        "etag": "^1.8.1",
        "finalhandler": "^2.1.0",
        "fresh": "^2.0.0",
        "http-errors": "^2.0.0",
        "merge-descriptors": "^2.0.0",
        "mime-types": "^3.0.0",
        "on-finished": "^2.4.1",
        "once": "^1.4.0",
        "parseurl": "^1.3.3",
        "proxy-addr": "^2.0.7",
        "qs": "^6.14.0",
        "range-parser": "^1.2.1",
        "router": "^2.2.0",
        "send": "^1.1.0",
        "serve-static": "^2.2.0",
        "statuses": "^2.0.1",
        "type-is": "^2.0.1",
        "vary": "^1.1.2"
      },
      "engines": {
        "node": ">= 18"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/finalhandler": {
      "version": "2.1.1",
      "resolved": "https://registry.npmjs.org/finalhandler/-/finalhandler-2.1.1.tgz",
      "integrity": "sha512-S8KoZgRZN+a5rNwqTxlZZePjT/4cnm0ROV70LedRHZ0p8u9fRID0hJUZQpkKLzro8LfmC8sx23bY6tVNxv8pQA==",
      "license": "MIT",
      "dependencies": {
        "debug": "^4.4.0",
        "encodeurl": "^2.0.0",
        "escape-html": "^1.0.3",
        "on-finished": "^2.4.1",
        "parseurl": "^1.3.3",
        "statuses": "^2.0.1"
      },
      "engines": {
        "node": ">= 18.0.0"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/forwarded": {
      "version": "0.2.0",
      "resolved": "https://registry.npmjs.org/forwarded/-/forwarded-0.2.0.tgz",
      "integrity": "sha512-buRG0fpBtRHSTCOASe6hD258tEubFoRLb4ZNA6NxMVHNw2gOcwHo9wyablzMzOA5z9xA9L1KNjk/Nt6MT9aYow==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.6"
      }
    },
    "node_modules/fresh": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/fresh/-/fresh-2.0.0.tgz",
      "integrity": "sha512-Rx/WycZ60HOaqLKAi6cHRKKI7zxWbJ31MhntmtwMoaTeF7XFH9hhBp8vITaMidfljRQ6eYWCKkaTK+ykVJHP2A==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.8"
      }
    },
    "node_modules/function-bind": {
      "version": "1.1.2",
      "resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.2.tgz",
      "integrity": "sha512-7XHNxH7qX9xG5mIwxkhumTox/MIRNcOgDrxWsMt2pAr23WHp6MrRlN7FBSFpCpr+oVO0F744iUgR82nJMfG2SA==",
      "license": "MIT",
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    },
    "node_modules/get-intrinsic": {
      "version": "1.3.0",
      "resolved": "https://registry.npmjs.org/get-intrinsic/-/get-intrinsic-1.3.0.tgz",
      "integrity": "sha512-9fSjSaos/fRIVIp+xSJlE6lfwhES7LNtKaCBIamHsjr2na1BiABJPo0mOjjz8GJDURarmCPGqaiVg5mfjb98CQ==",
      "license": "MIT",
      "dependencies": {
        "call-bind-apply-helpers": "^1.0.2",
        "es-define-property": "^1.0.1",
        "es-errors": "^1.3.0",
        "es-object-atoms": "^1.1.1",
        "function-bind": "^1.1.2",
        "get-proto": "^1.0.1",
        "gopd": "^1.2.0",
        "has-symbols": "^1.1.0",
        "hasown": "^2.0.2",
        "math-intrinsics": "^1.1.0"
      },
      "engines": {
        "node": ">= 0.4"
      },
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    },
    "node_modules/get-proto": {
      "version": "1.0.1",
      "resolved": "https://registry.npmjs.org/get-proto/-/get-proto-1.0.1.tgz",
      "integrity": "sha512-sTSfBjoXBp89JvIKIefqw7U2CCebsc74kiY6awiGogKtoSGbgjYE/G/+l9sF3MWFPNc9IcoOC4ODfKHfxFmp0g==",
      "license": "MIT",
      "dependencies": {
        "dunder-proto": "^1.0.1",
        "es-object-atoms": "^1.0.0"
      },
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/gopd": {
      "version": "1.2.0",
      "resolved": "https://registry.npmjs.org/gopd/-/gopd-1.2.0.tgz",
      "integrity": "sha512-ZUKRh6/kUFoAiTAtTYPZJ3hw9wNxx+BIBOijnlG9PnrJsCcSjs1wyyD6vJpaYtgnzDrKYRSqf3OO6Rfa93xsRg==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.4"
      },
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    },
    "node_modules/has-symbols": {
      "version": "1.1.0",
      "resolved": "https://registry.npmjs.org/has-symbols/-/has-symbols-1.1.0.tgz",
      "integrity": "sha512-1cDNdwJ2Jaohmb3sg4OmKaMBwuC48sYni5HUw2DvsC8LjGTLK9h+eb1X6RyuOHe4hT0ULCW68iomhjUoKUqlPQ==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.4"
      },
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    },
    "node_modules/hasown": {
      "version": "2.0.4",
      "resolved": "https://registry.npmjs.org/hasown/-/hasown-2.0.4.tgz",
      "integrity": "sha512-T2UbfbBEF32wiepXIsMlTW9+dDYC6wMh/t/vYA4tuOMKqWz/n3vr1NFSxQiyP+zk2mXsoMA/i/7qV6LKut1t1A==",
      "license": "MIT",
      "dependencies": {
        "function-bind": "^1.1.2"
      },
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/http-errors": {
      "version": "2.0.1",
      "resolved": "https://registry.npmjs.org/http-errors/-/http-errors-2.0.1.tgz",
      "integrity": "sha512-4FbRdAX+bSdmo4AUFuS0WNiPz8NgFt+r8ThgNWmlrjQjt1Q7ZR9+zTlce2859x4KSXrwIsaeTqDoKQmtP8pLmQ==",
      "license": "MIT",
      "dependencies": {
        "depd": "~2.0.0",
        "inherits": "~2.0.4",
        "setprototypeof": "~1.2.0",
        "statuses": "~2.0.2",
        "toidentifier": "~1.0.1"
      },
      "engines": {
        "node": ">= 0.8"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/iconv-lite": {
      "version": "0.7.3",
      "resolved": "https://registry.npmjs.org/iconv-lite/-/iconv-lite-0.7.3.tgz",
      "integrity": "sha512-IKXpvIzjnC9XTAUbVBcMfGS0EPaIXtW6v+zr+RRp+hqULEpo0owZax6wyRwPOJbWbzjYspQwusTsfVr0ifh4uQ==",
      "license": "MIT",
      "dependencies": {
        "safer-buffer": ">= 2.1.2 < 3.0.0"
      },
      "engines": {
        "node": ">=0.10.0"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/inherits": {
      "version": "2.0.4",
      "resolved": "https://registry.npmjs.org/inherits/-/inherits-2.0.4.tgz",
      "integrity": "sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ==",
      "license": "ISC"
    },
    "node_modules/ipaddr.js": {
      "version": "1.9.1",
      "resolved": "https://registry.npmjs.org/ipaddr.js/-/ipaddr.js-1.9.1.tgz",
      "integrity": "sha512-0KI/607xoxSToH7GjN1FfSbLoU0+btTicjsQSWQlh/hZykN8KpmMf7uYwPW3R+akZ6R/w18ZlXSHBYXiYUPO3g==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.10"
      }
    },
    "node_modules/is-promise": {
      "version": "4.0.0",
      "resolved": "https://registry.npmjs.org/is-promise/-/is-promise-4.0.0.tgz",
      "integrity": "sha512-hvpoI6korhJMnej285dSg6nu1+e6uxs7zG3BYAm5byqDsgJNWwxzM6z6iZiAgQR4TJ30JmBTOwqZUw3WlyH3AQ==",
      "license": "MIT"
    },
    "node_modules/math-intrinsics": {
      "version": "1.1.0",
      "resolved": "https://registry.npmjs.org/math-intrinsics/-/math-intrinsics-1.1.0.tgz",
      "integrity": "sha512-/IXtbwEk5HTPyEwyKX6hGkYXxM9nbj64B+ilVJnC/R6B0pH5G4V3b0pVbL7DBj4tkhBAppbQUlf6F6Xl9LHu1g==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.4"
      }
    },
    "node_modules/media-typer": {
      "version": "1.1.1",
      "resolved": "https://registry.npmjs.org/media-typer/-/media-typer-1.1.1.tgz",
      "integrity": "sha512-yz3xRaG20c6/BOzvYoDaGtPmGscs7YivItZEEqe6GbwNfHuxu9YNmvnEkMzKldAGY4/80pRcQRZSEnhquk9XuQ==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.8"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/merge-descriptors": {
      "version": "2.0.0",
      "resolved": "https://registry.npmjs.org/merge-descriptors/-/merge-descriptors-2.0.0.tgz",
      "integrity": "sha512-Snk314V5ayFLhp3fkUREub6WtjBfPdCPY1Ln8/8munuLuiYhsABgBVWsozAG+MWMbVEvcdcpbi9R7ww22l9Q3g==",
      "license": "MIT",
      "engines": {
        "node": ">=18"
      },
      "funding": {
        "url": "https://github.com/sponsors/sindresorhus"
      }
    },
    "node_modules/mime-db": {
      "version": "1.54.0",
      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.54.0.tgz",
      "integrity": "sha512-aU5EJuIN2WDemCcAp2vFBfp/m4EAhWJnUNSSw0ixs7/kXbd6Pg64EmwJkNdFhB8aWt1sH2CTXrLxo/iAGV3oPQ==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.6"
      }
    },
    "node_modules/mime-types": {
      "version": "3.0.2",
      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-3.0.2.tgz",
      "integrity": "sha512-Lbgzdk0h4juoQ9fCKXW4by0UJqj+nOOrI9MJ1sSj4nI8aI2eo1qmvQEie4VD1glsS250n15LsWsYtCugiStS5A==",
      "license": "MIT",
      "dependencies": {
        "mime-db": "^1.54.0"
      },
      "engines": {
        "node": ">=18"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/ms": {
      "version": "2.1.3",
      "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.3.tgz",
      "integrity": "sha512-6FlzubTLZG3J2a/NVCAleEhjzq5oxgHyaCU9yYXvcLsvoVaHJq/s5xXI6/XXP6tz7R9xAOtHnSO/tXtF3WRTlA==",
      "license": "MIT"
    },
    "node_modules/negotiator": {
      "version": "1.1.0",
      "resolved": "https://registry.npmjs.org/negotiator/-/negotiator-1.1.0.tgz",
      "integrity": "sha512-NMPBRMJgiQHjbd8phG3Vebdx4kZ1H121rbl5IkMqeOsahptB9BKo/d7oJ3zTXqTgagn2bWlNSXkh0QUGM31RYg==",
      "license": "MIT",
      "dependencies": {
        "content-type": "^2.1.0"
      },
      "engines": {
        "node": ">=18"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/negotiator/node_modules/content-type": {
      "version": "2.1.0",
      "resolved": "https://registry.npmjs.org/content-type/-/content-type-2.1.0.tgz",
      "integrity": "sha512-mj7UPXE0jaqaOsukNZRUEfEi2AcL7C/vwmwcHV0O97eO1E1pxBZuyjlZrx5seTaNBg1U6+o35wpa35Qfcc+7ag==",
      "license": "MIT",
      "engines": {
        "node": ">=18"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/object-inspect": {
      "version": "1.13.4",
      "resolved": "https://registry.npmjs.org/object-inspect/-/object-inspect-1.13.4.tgz",
      "integrity": "sha512-W67iLl4J2EXEGTbfeHCffrjDfitvLANg0UlX3wFUUSTx92KXRFegMHUVgSqE+wvhAbi4WqjGg9czysTV2Epbew==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.4"
      },
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    },
    "node_modules/on-finished": {
      "version": "2.4.1",
      "resolved": "https://registry.npmjs.org/on-finished/-/on-finished-2.4.1.tgz",
      "integrity": "sha512-oVlzkg3ENAhCk2zdv7IJwd/QUD4z2RxRwpkcGY8psCVcCYZNq4wYnVWALHM+brtuJjePWiYF/ClmuDr8Ch5+kg==",
      "license": "MIT",
      "dependencies": {
        "ee-first": "1.1.1"
      },
      "engines": {
        "node": ">= 0.8"
      }
    },
    "node_modules/once": {
      "version": "1.4.0",
      "resolved": "https://registry.npmjs.org/once/-/once-1.4.0.tgz",
      "integrity": "sha512-lNaJgI+2Q5URQBkccEKHTQOPaXdUxnZZElQTZY0MFUAuaEqe1E+Nyvgdz/aIyNi6Z9MzO5dv1H8n58/GELp3+w==",
      "license": "ISC",
      "dependencies": {
        "wrappy": "1"
      }
    },
    "node_modules/parseurl": {
      "version": "1.3.3",
      "resolved": "https://registry.npmjs.org/parseurl/-/parseurl-1.3.3.tgz",
      "integrity": "sha512-CiyeOxFT/JZyN5m0z9PfXw4SCBJ6Sygz1Dpl0wqjlhDEGGBP1GnsUVEL0p63hoG1fcj3fHynXi9NYO4nWOL+qQ==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.8"
      }
    },
    "node_modules/path-to-regexp": {
      "version": "8.4.2",
      "resolved": "https://registry.npmjs.org/path-to-regexp/-/path-to-regexp-8.4.2.tgz",
      "integrity": "sha512-qRcuIdP69NPm4qbACK+aDogI5CBDMi1jKe0ry5rSQJz8JVLsC7jV8XpiJjGRLLol3N+R5ihGYcrPLTno6pAdBA==",
      "license": "MIT",
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/proxy-addr": {
      "version": "2.0.7",
      "resolved": "https://registry.npmjs.org/proxy-addr/-/proxy-addr-2.0.7.tgz",
      "integrity": "sha512-llQsMLSUDUPT44jdrU/O37qlnifitDP+ZwrmmZcoSKyLKvtZxpyV0n2/bD/N4tBAAZ/gJEdZU7KMraoK1+XYAg==",
      "license": "MIT",
      "dependencies": {
        "forwarded": "0.2.0",
        "ipaddr.js": "1.9.1"
      },
      "engines": {
        "node": ">= 0.10"
      }
    },
    "node_modules/qs": {
      "version": "6.15.3",
      "resolved": "https://registry.npmjs.org/qs/-/qs-6.15.3.tgz",
      "integrity": "sha512-O9gl3zCl5h5blw1KGUzQKhA5oUXSl8rwUIM5o0S3nCXMliSvy5Dzx7/DJcI+SwgICv+IneSZwhBh1oSyEHA71A==",
      "license": "BSD-3-Clause",
      "dependencies": {
        "es-define-property": "^1.0.1",
        "side-channel": "^1.1.1"
      },
      "engines": {
        "node": ">=0.6"
      },
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    },
    "node_modules/range-parser": {
      "version": "1.3.0",
      "resolved": "https://registry.npmjs.org/range-parser/-/range-parser-1.3.0.tgz",
      "integrity": "sha512-hek2mFQpPuI4E1BBKrSto+BU3e3x4xuarsbiwr3+lf7p44juvFMV0XFWQAP3xUyqXA4RrXLIoaSUGbSt056ZMw==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.6"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/raw-body": {
      "version": "3.0.2",
      "resolved": "https://registry.npmjs.org/raw-body/-/raw-body-3.0.2.tgz",
      "integrity": "sha512-K5zQjDllxWkf7Z5xJdV0/B0WTNqx6vxG70zJE4N0kBs4LovmEYWJzQGxC9bS9RAKu3bgM40lrd5zoLJ12MQ5BA==",
      "license": "MIT",
      "dependencies": {
        "bytes": "~3.1.2",
        "http-errors": "~2.0.1",
        "iconv-lite": "~0.7.0",
        "unpipe": "~1.0.0"
      },
      "engines": {
        "node": ">= 0.10"
      }
    },
    "node_modules/router": {
      "version": "2.2.0",
      "resolved": "https://registry.npmjs.org/router/-/router-2.2.0.tgz",
      "integrity": "sha512-nLTrUKm2UyiL7rlhapu/Zl45FwNgkZGaCpZbIHajDYgwlJCOzLSk+cIPAnsEqV955GjILJnKbdQC1nVPz+gAYQ==",
      "license": "MIT",
      "dependencies": {
        "debug": "^4.4.0",
        "depd": "^2.0.0",
        "is-promise": "^4.0.0",
        "parseurl": "^1.3.3",
        "path-to-regexp": "^8.0.0"
      },
      "engines": {
        "node": ">= 18"
      }
    },
    "node_modules/safer-buffer": {
      "version": "2.1.2",
      "resolved": "https://registry.npmjs.org/safer-buffer/-/safer-buffer-2.1.2.tgz",
      "integrity": "sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg==",
      "license": "MIT"
    },
    "node_modules/send": {
      "version": "1.2.1",
      "resolved": "https://registry.npmjs.org/send/-/send-1.2.1.tgz",
      "integrity": "sha512-1gnZf7DFcoIcajTjTwjwuDjzuz4PPcY2StKPlsGAQ1+YH20IRVrBaXSWmdjowTJ6u8Rc01PoYOGHXfP1mYcZNQ==",
      "license": "MIT",
      "dependencies": {
        "debug": "^4.4.3",
        "encodeurl": "^2.0.0",
        "escape-html": "^1.0.3",
        "etag": "^1.8.1",
        "fresh": "^2.0.0",
        "http-errors": "^2.0.1",
        "mime-types": "^3.0.2",
        "ms": "^2.1.3",
        "on-finished": "^2.4.1",
        "range-parser": "^1.2.1",
        "statuses": "^2.0.2"
      },
      "engines": {
        "node": ">= 18"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/serve-static": {
      "version": "2.2.1",
      "resolved": "https://registry.npmjs.org/serve-static/-/serve-static-2.2.1.tgz",
      "integrity": "sha512-xRXBn0pPqQTVQiC8wyQrKs2MOlX24zQ0POGaj0kultvoOCstBQM5yvOhAVSUwOMjQtTvsPWoNCHfPGwaaQJhTw==",
      "license": "MIT",
      "dependencies": {
        "encodeurl": "^2.0.0",
        "escape-html": "^1.0.3",
        "parseurl": "^1.3.3",
        "send": "^1.2.0"
      },
      "engines": {
        "node": ">= 18"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/setprototypeof": {
      "version": "1.2.0",
      "resolved": "https://registry.npmjs.org/setprototypeof/-/setprototypeof-1.2.0.tgz",
      "integrity": "sha512-E5LDX7Wrp85Kil5bhZv46j8jOeboKq5JMmYM3gVGdGH8xFpPWXUMsNrlODCrkoxMEeNi/XZIwuRvY4XNwYMJpw==",
      "license": "ISC"
    },
    "node_modules/side-channel": {
      "version": "1.1.1",
      "resolved": "https://registry.npmjs.org/side-channel/-/side-channel-1.1.1.tgz",
      "integrity": "sha512-6x6dK6zJdpTzF4sQeNYxwtvBzf6Eg4GtlesS94HOvTudUeyK2WXAaIfmDgsyslYrRBeFIlsi54AYsFGUuhmvrQ==",
      "license": "MIT",
      "dependencies": {
        "es-errors": "^1.3.0",
        "object-inspect": "^1.13.4",
        "side-channel-list": "^1.0.1",
        "side-channel-map": "^1.0.1",
        "side-channel-weakmap": "^1.0.2"
      },
      "engines": {
        "node": ">= 0.4"
      },
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    },
    "node_modules/side-channel-list": {
      "version": "1.0.1",
      "resolved": "https://registry.npmjs.org/side-channel-list/-/side-channel-list-1.0.1.tgz",
      "integrity": "sha512-mjn/0bi/oUURjc5Xl7IaWi/OJJJumuoJFQJfDDyO46+hBWsfaVM65TBHq2eoZBhzl9EchxOijpkbRC8SVBQU0w==",
      "license": "MIT",
      "dependencies": {
        "es-errors": "^1.3.0",
        "object-inspect": "^1.13.4"
      },
      "engines": {
        "node": ">= 0.4"
      },
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    },
    "node_modules/side-channel-map": {
      "version": "1.0.1",
      "resolved": "https://registry.npmjs.org/side-channel-map/-/side-channel-map-1.0.1.tgz",
      "integrity": "sha512-VCjCNfgMsby3tTdo02nbjtM/ewra6jPHmpThenkTYh8pG9ucZ/1P8So4u4FGBek/BjpOVsDCMoLA/iuBKIFXRA==",
      "license": "MIT",
      "dependencies": {
        "call-bound": "^1.0.2",
        "es-errors": "^1.3.0",
        "get-intrinsic": "^1.2.5",
        "object-inspect": "^1.13.3"
      },
      "engines": {
        "node": ">= 0.4"
      },
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    },
    "node_modules/side-channel-weakmap": {
      "version": "1.0.2",
      "resolved": "https://registry.npmjs.org/side-channel-weakmap/-/side-channel-weakmap-1.0.2.tgz",
      "integrity": "sha512-WPS/HvHQTYnHisLo9McqBHOJk2FkHO/tlpvldyrnem4aeQp4hai3gythswg6p01oSoTl58rcpiFAjF2br2Ak2A==",
      "license": "MIT",
      "dependencies": {
        "call-bound": "^1.0.2",
        "es-errors": "^1.3.0",
        "get-intrinsic": "^1.2.5",
        "object-inspect": "^1.13.3",
        "side-channel-map": "^1.0.1"
      },
      "engines": {
        "node": ">= 0.4"
      },
      "funding": {
        "url": "https://github.com/sponsors/ljharb"
      }
    },
    "node_modules/statuses": {
      "version": "2.0.2",
      "resolved": "https://registry.npmjs.org/statuses/-/statuses-2.0.2.tgz",
      "integrity": "sha512-DvEy55V3DB7uknRo+4iOGT5fP1slR8wQohVdknigZPMpMstaKJQWhwiYBACJE3Ul2pTnATihhBYnRhZQHGBiRw==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.8"
      }
    },
    "node_modules/toidentifier": {
      "version": "1.0.1",
      "resolved": "https://registry.npmjs.org/toidentifier/-/toidentifier-1.0.1.tgz",
      "integrity": "sha512-o5sSPKEkg/DIQNmH43V0/uerLrpzVedkUh8tGNvaeXpfpuwjKenlSox/2O/BTlZUtEe+JG7s5YhEz608PlAHRA==",
      "license": "MIT",
      "engines": {
        "node": ">=0.6"
      }
    },
    "node_modules/type-is": {
      "version": "2.1.0",
      "resolved": "https://registry.npmjs.org/type-is/-/type-is-2.1.0.tgz",
      "integrity": "sha512-faYHw0anBbc/kWF3zFTEnxSFOAGUX9GFbOBthvDdLsIlEoWOFOtS0zgCiQYwIskL9iGXZL3kAXD8OoZ4GmMATA==",
      "license": "MIT",
      "dependencies": {
        "content-type": "^2.0.0",
        "media-typer": "^1.1.0",
        "mime-types": "^3.0.0"
      },
      "engines": {
        "node": ">= 18"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/type-is/node_modules/content-type": {
      "version": "2.1.0",
      "resolved": "https://registry.npmjs.org/content-type/-/content-type-2.1.0.tgz",
      "integrity": "sha512-mj7UPXE0jaqaOsukNZRUEfEi2AcL7C/vwmwcHV0O97eO1E1pxBZuyjlZrx5seTaNBg1U6+o35wpa35Qfcc+7ag==",
      "license": "MIT",
      "engines": {
        "node": ">=18"
      },
      "funding": {
        "type": "opencollective",
        "url": "https://opencollective.com/express"
      }
    },
    "node_modules/unpipe": {
      "version": "1.0.0",
      "resolved": "https://registry.npmjs.org/unpipe/-/unpipe-1.0.0.tgz",
      "integrity": "sha512-pjy2bYhSsufwWlKwPc+l3cN7+wuJlK6uz0YdJEOlQDbl6jo/YlPi4mb8agUkVC8BF7V8NuzeyPNqRksA3hztKQ==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.8"
      }
    },
    "node_modules/vary": {
      "version": "1.1.2",
      "resolved": "https://registry.npmjs.org/vary/-/vary-1.1.2.tgz",
      "integrity": "sha512-BNGbWLfd0eUPabhkXUVm0j8uuvREyTh5ovRa/dyow/BqAbZJyC+5fU+IzQOzmAKzYqYRAISoRhdQr3eIZ/PXqg==",
      "license": "MIT",
      "engines": {
        "node": ">= 0.8"
      }
    },
    "node_modules/wrappy": {
      "version": "1.0.2",
      "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.2.tgz",
      "integrity": "sha512-l4Sp/DRseor9wL6EvV2+TuQn63dMkPjZ/sp9XkghTEbV9KlPS1xUsZ3u7/IQO4wxtcFB4bgpQPRcR3QCvezPcQ==",
      "license": "ISC"
    }
  }
}
package.json
{
  "name": "sample-express-urlencoded",
  "version": "1.0.0",
  "type": "module",
  "private": true,
  "dependencies": {
    "express": "5.1.0"
  }
}
spec.json
{
  "schemaVersion": 1,
  "goal": "verify express.urlencoded in pkg:npm/express@5.1.0",
  "kind": "HOW",
  "packages": [
    "pkg:npm/express@5.1.0"
  ],
  "symbols": [
    "express.urlencoded"
  ]
}
test/contract.mjs
import assert from 'node:assert/strict';
import http from 'node:http';
import express from 'express';

async function runTests() {
  // 1. express.urlencoded({ extended: false }) parses flat URL-encoded form data into req.body key-value pairs
  await new Promise((resolve, reject) => {
    const app = express();
    app.use(express.urlencoded({ extended: false }));
    app.post('/test-flat', (req, res) => {
      res.json(req.body);
    });

    const server = http.createServer(app);
    server.listen(0, '127.0.0.1', () => {
      const port = server.address().port;
      const postData = 'title=Clean+Architecture&author=Expert&tag=node';
      const req = http.request(`http://127.0.0.1:${port}/test-flat`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded',
          'Content-Length': Buffer.byteLength(postData)
        }
      }, (res) => {
        assert.equal(res.statusCode, 200);
        let data = '';
        res.on('data', chunk => { data += chunk; });
        res.on('end', () => {
          const parsed = JSON.parse(data);
          assert.deepEqual(parsed, {
            title: 'Clean Architecture',
            author: 'Expert',
            tag: 'node'
          });
          server.close(() => resolve());
        });
      });
      req.on('error', reject);
      req.write(postData);
      req.end();
    });
  });

  // 2. express.urlencoded({ extended: true }) parses nested URL-encoded form data into nested objects and arrays
  await new Promise((resolve, reject) => {
    const app = express();
    app.use(express.urlencoded({ extended: true }));
    app.post('/test-nested', (req, res) => {
      res.json(req.body);
    });

    const server = http.createServer(app);
    server.listen(0, '127.0.0.1', () => {
      const port = server.address().port;
      const postData = 'user[name]=Alice&user[roles][]=admin&user[roles][]=editor';
      const req = http.request(`http://127.0.0.1:${port}/test-nested`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded',
          'Content-Length': Buffer.byteLength(postData)
        }
      }, (res) => {
        assert.equal(res.statusCode, 200);
        let data = '';
        res.on('data', chunk => { data += chunk; });
        res.on('end', () => {
          const parsed = JSON.parse(data);
          assert.deepEqual(parsed, {
            user: {
              name: 'Alice',
              roles: ['admin', 'editor']
            }
          });
          server.close(() => resolve());
        });
      });
      req.on('error', reject);
      req.write(postData);
      req.end();
    });
  });

  // 3. express.urlencoded({ limit }) rejects payloads exceeding the byte limit with a 413 entity.too.large status
  await new Promise((resolve, reject) => {
    const app = express();
    app.use(express.urlencoded({ extended: false, limit: '20b' }));
    app.post('/test-limit', (req, res) => {
      res.json(req.body);
    });
    app.use((err, req, res, next) => {
      res.status(err.status || 500).json({ error: err.message, type: err.type });
    });

    const server = http.createServer(app);
    server.listen(0, '127.0.0.1', () => {
      const port = server.address().port;
      const postData = 'data=this_is_a_very_long_payload_exceeding_twenty_bytes';
      const req = http.request(`http://127.0.0.1:${port}/test-limit`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded',
          'Content-Length': Buffer.byteLength(postData)
        }
      }, (res) => {
        assert.equal(res.statusCode, 413);
        let data = '';
        res.on('data', chunk => { data += chunk; });
        res.on('end', () => {
          const parsed = JSON.parse(data);
          assert.equal(parsed.type, 'entity.too.large');
          server.close(() => resolve());
        });
      });
      req.on('error', reject);
      req.write(postData);
      req.end();
    });
  });

  // 4. express.urlencoded() ignores requests with unmatched Content-Type headers leaving req.body untouched
  await new Promise((resolve, reject) => {
    const app = express();
    app.use(express.urlencoded({ extended: false }));
    app.post('/test-unmatched', (req, res) => {
      res.json({ hasBody: req.body !== undefined, body: req.body || null });
    });

    const server = http.createServer(app);
    server.listen(0, '127.0.0.1', () => {
      const port = server.address().port;
      const postData = 'plain text payload';
      const req = http.request(`http://127.0.0.1:${port}/test-unmatched`, {
        method: 'POST',
        headers: {
          'Content-Type': 'text/plain',
          'Content-Length': Buffer.byteLength(postData)
        }
      }, (res) => {
        assert.equal(res.statusCode, 200);
        let data = '';
        res.on('data', chunk => { data += chunk; });
        res.on('end', () => {
          const parsed = JSON.parse(data);
          assert.equal(parsed.hasBody, false);
          server.close(() => resolve());
        });
      });
      req.on('error', reject);
      req.write(postData);
      req.end();
    });
  });

  // 5. express.urlencoded() parses an empty URL-encoded request body into an empty object
  await new Promise((resolve, reject) => {
    const app = express();
    app.use(express.urlencoded({ extended: false }));
    app.post('/test-empty', (req, res) => {
      res.json(req.body);
    });

    const server = http.createServer(app);
    server.listen(0, '127.0.0.1', () => {
      const port = server.address().port;
      const req = http.request(`http://127.0.0.1:${port}/test-empty`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded',
          'Content-Length': 0
        }
      }, (res) => {
        assert.equal(res.statusCode, 200);
        let data = '';
        res.on('data', chunk => { data += chunk; });
        res.on('end', () => {
          const parsed = JSON.parse(data);
          assert.deepEqual(parsed, {});
          server.close(() => resolve());
        });
      });
      req.on('error', reject);
      req.end();
    });
  });

  // 6. express.urlencoded({ type }) parses URL-encoded bodies matching a custom Content-Type header
  await new Promise((resolve, reject) => {
    const app = express();
    app.use(express.urlencoded({ extended: false, type: 'application/x-custom-urlencoded' }));
    app.post('/test-custom-type', (req, res) => {
      res.json(req.body);
    });

    const server = http.createServer(app);
    server.listen(0, '127.0.0.1', () => {
      const port = server.address().port;
      const postData = 'status=completed&code=200';
      const req = http.request(`http://127.0.0.1:${port}/test-custom-type`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/x-custom-urlencoded',
          'Content-Length': Buffer.byteLength(postData)
        }
      }, (res) => {
        assert.equal(res.statusCode, 200);
        let data = '';
        res.on('data', chunk => { data += chunk; });
        res.on('end', () => {
          const parsed = JSON.parse(data);
          assert.deepEqual(parsed, {
            status: 'completed',
            code: '200'
          });
          server.close(() => resolve());
        });
      });
      req.on('error', reject);
      req.write(postData);
      req.end();
    });
  });

  console.log('Contract tests passed successfully.');
}

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

Исходный сидер

аноним