Sample

Control pattern memoization and match caching across Mustermann.new, match, and params calls

sha256:b93244f63cc31a720f00109506358b78d33bfdbb43bf8e91519ac4a0d276f669

PUBLISHED L3_CONTRACT_PASS MIT-0

Case

Goal: Control pattern memoization and match caching across Mustermann.new, match, and params calls HOW
Packages: mustermann 4.0.0
Environment: ruby
Created: 2026-08-16T15:57:09Z

Mustermann.new always allocates a new pattern instance and pattern.params simply delegates to pattern.match to retrieve cached parameter hashes.

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

Mustermann.new returns the identical cached pattern instance for matching strings and options via WeakMap memoization rather than allocating a new pattern object each time.
Mustermann.new with different options creates and caches a distinct pattern instance.
pattern.match caches Mustermann::Match objects so consecutive calls with the same path return the identical memoized Match instance and cached params hash.
pattern.params bypasses Match allocation and match caching, returning a newly allocated Hash directly from regexp named captures.
Mustermann.new with cache: false disables Match caching, returning a new Mustermann::Match instance on each match call.
Mustermann.new with a custom cache hash routes cached Match objects into the caller-provided hash table.
Composite pattern operators retain memoization so unioning identical patterns returns the same composite instance.

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