示例
express 4.21.2: Distinguish Express error-handling middleware from standard middleware strictly via four-parameter arity (fn.length === 4)
已验证示例 — npm express 4.21.2: Distinguish Express error-handling middleware from standard middleware strictly via four-parameter arity (fn.length === 4).…
sha256:7d9166d737c904e7ef96c639c4509493cd6cb139888b54e6daffdaed0ec6019c
本网络只提供一件事：能构建的样本。它在沙箱中运行并保留签名回执。它不评级、不担保——同样的代码能否在你的环境构建，它没有测量过。
提交了通过的契约回执的不同签名密钥数量。为 1 表示只有作者；大于 1 表示还有其他人构建过。密钥是自行生成的，背后没有注册身份，因此计的是密钥而非人。
MIT-0
执行证据
声明的环境与签名的运行分开呈现，你可以看到这个样本究竟运行了什么、在哪里运行。
- 证据依据
- 签名契约通过
- 验证回执
- 2
- 构建过它的签名密钥
- 2
声明的环境
node linux x64 node node npm
验证运行环境
| 环境 | 契约 | 阶段 | 运行日期 |
|---|---|---|---|
| node 22 · linux alpine/x64 · docker ed25519:d91480838ac982c9 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1 |
2026-08-17 |
| node 22 · linux alpine/x64 · docker ed25519:2175b912ea1c23b1 | PASS | compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS CONTAINER_RUN · node-typescript@1 |
2026-08-18 |
案例
HOW- 目标
- Distinguish Express error-handling middleware from standard middleware strictly via four-parameter arity (fn.length === 4)
- 符号
-
- express
- app.use
- 环境
- node
- 创建时间
- 2026-08-17T01:50:22Z
契约
- Express skips 3-parameter error handlers (err, req, res) during error routing because it identifies error middleware solely by checking fn.length === 4, executing only 4-parameter functions (err, req, res, next) while running 3-parameter functions on normal requests with shifted arguments
- Middleware with default fourth parameter (err, req, res, next = () => {}) has fn.length === 3 and is skipped during error routing
- Middleware with rest parameters (...args) has fn.length === 0 and is skipped during error routing
- Standard middleware defined with four parameters (req, res, next, unused) has fn.length === 4 and is skipped during normal request routing
文件
- NOTES.md
- csx.json
- package-lock.json
- package.json
- test/contract.mjs