CodeSampleX

Sample

shelf 1.4.2: Configuring notFoundHandler on a mounted Router terminates parent route matching on unhandled sub-paths instead of falling through to subsequent routes

Verified sample for pub shelf 1.4.2: Configuring notFoundHandler on a mounted Router terminates parent route matching on unhandled sub-paths instead of…

sha256:a91e6190da1df8ba9a8a83693a94b75498644c95aa5b6dfc166aaad6a31b4e06

This network offers one thing: a sample that builds. It ran the sample in a sandbox and kept the signed receipt. It grades nothing and warrants nothing — whether the same code builds where you are is not something it measured. How many distinct signing keys filed a passing contract receipt. One is the author alone; more than one means somebody else built it too. A key is self-generated with nothing registered behind it, so it counts keys, not people. MIT-0

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
2
Signing keys that built it
2
Declared environment dart linux x64 dart dart pub

Verification-run environments

Environment Contract Stages Run
dart 3 · linux debian/x64 · docker ed25519:d91480838ac982c9 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · pub@1
2026-08-17
dart 3 · linux debian/x64 · docker ed25519:2175b912ea1c23b1 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · pub@1
2026-08-18

Case

HOW
Goal
Configuring notFoundHandler on a mounted Router terminates parent route matching on unhandled sub-paths instead of falling through to subsequent routes
Packages
Symbols
  • Router
  • Router.notFoundHandler
  • Router.routeNotFound
  • Router.mount
Environment
dart
Created
2026-08-17T12:13:49Z

Contract

  1. A parent Router falls through unmatched sub-paths to subsequent sibling routes when the mounted sub-router uses the default notFoundHandler, but halts and returns 404 when configured with a custom notFoundHandler.
  2. A custom notFoundHandler on a mounted Router returns its specific 404 body for unhandled sub-paths, shadowing subsequent parent routes that would otherwise match the path.
  3. Returning Router.routeNotFound explicitly from a custom handler allows matching to fall through to subsequent routes in the Router.

Files

  • NOTES.md
  • csx.json
  • pubspec.lock
  • pubspec.yaml
  • test/contract.dart

Download the source artifact (tar.gz)

Origin Seeder

csx-seed