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Sample

express 5.1.0: Fix express 4 routes that throw "Missing parameter name" or "Unexpected ?" at startup after upgrading to express 5

Verified sample for npm express 5.1.0: Fix express 4 routes that throw "Missing parameter name" or "Unexpected ?" at startup after upgrading to express 5.…

sha256:bb95306081deb0d7bdd735b0ca6f0182f77216c5d0426ee0146b7562efe7facc

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Execution evidence

The declared environment and the signed runs are kept apart, so you can see exactly what this sample ran and where.

Evidence basis
Signed contract pass
Verification receipts
5
Signing keys that built it
2
Declared environment node 22 linux x64 node 22 npm

Verification-run environments

Environment Contract Stages Run
node 22 · linux alpine/x64 · docker ed25519:a2ec939a4c60e243 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1
2026-08-13
node 22 · linux alpine/x64 · docker ed25519:a2ec939a4c60e243 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1
2026-08-13
node 22 · linux alpine/x64 · docker ed25519:a2ec939a4c60e243 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1
2026-08-13
node 22 · linux alpine/x64 · docker ed25519:a2ec939a4c60e243 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · node-typescript@1
2026-08-13
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

Case

FIX
Goal
Fix express 4 routes that throw "Missing parameter name" or "Unexpected ?" at startup after upgrading to express 5
Packages
Symbols
  • express
  • app.get
  • req.params
  • req.query
Environment
node 22
Created
2026-08-13T14:19:55Z

Contract

  1. assert express 5 throws TypeError 'Unexpected ?' when the express 4 path '/users/:id?' is registered
  2. assert express 5 throws TypeError 'Missing parameter name' for the unnamed wildcards '*' and '/files/*'
  3. start the migrated app on an ephemeral port
  4. assert '/users{/:id}' serves /users/42 with params.id '42' and a bare /users with no id
  5. assert the named wildcard '/files/*splat' captures the remaining path as an array of segments
  6. assert assigning req.query throws because express 5 exposes it as a getter, and that a write onto the returned object is discarded

Files

  • csx.json
  • package-lock.json
  • package.json
  • src/app.mjs
  • src/v4-habits.mjs
  • test/contract.mjs

Download the source artifact (tar.gz)

Origin Seeder

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