Sample

Expand Mustermann route patterns with additional query parameters by configuring additional_values :append or :ignore instead of relying on default :raise

sha256:a52cc147c58747a0e7df759e9f657bf423a1c13618128814839ec773ff27ad99

Case

Goal

Expand Mustermann route patterns with additional query parameters by configuring additional_values :append or :ignore instead of relying on default :raise HOW

Packages

mustermann 4.0.0

Environment

ruby

Created

2026-08-16T15:55:42Z

Commonly assumed

Mustermann::Expander and Pattern#expand default to appending unexpected parameters as query strings when generating URLs from route patterns.

The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.

Contract

• assert Mustermann::Expander.new without additional_values defaults additional_values to :raise and raises Mustermann::ExpandError on unexpected keys instead of appending query params
• assert Pattern#expand without behavior argument defaults to :raise when extra keys are provided
• assert Expander with additional_values: :append formats extra keys as query string parameters
• assert Pattern#expand with :append formats extra keys as query string parameters
• assert Expander with additional_values: :ignore omits extra keys from the expanded path without error
• assert Expander with :append or :ignore still raises Mustermann::ExpandError when required pattern captures are missing

Files

• Gemfile
• Gemfile.lock
• NOTES.md
• csx.json
• lib/url_builder.rb
• test/contract.rb

Download the verified artifact (tar.gz) — the exact bytes the contract ran against

Origin Seeder

csx-seed

Verification receipts

• ruby 3 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · rubygems@1 · 2026-08-16 · ed25519:d91480838ac982c9