Sample

Handle Mustermann capture type casting across built-in AST converters, POSIX character classes, polymorphic converter unions, and expand roundtripping

sha256:876d66cea0502af8f4f6e05ed74179faedec2c610e764f8afdc67e86ad937985

PUBLISHED L3_CONTRACT_PASS MIT-0

Case

Goal: Handle Mustermann capture type casting across built-in AST converters, POSIX character classes, polymorphic converter unions, and expand roundtripping HOW
Packages: mustermann 4.0.0
Environment: ruby
Created: 2026-08-16T15:55:35Z

Mustermann capture options accept arbitrary Ruby classes and parse them on match, while all other capture groups return raw String parameters.

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

Mustermann capture options only accept built-in converter types (Date, Gem::Version, Float, Integer, Symbol), raising Mustermann::CompileError on arbitrary classes like Time while typecasting extracted parameters into Ruby class instances and round-tripping them through expand.
Passing an array of capture types such as [Integer, Date, :slug] creates a polymorphic capture that matches and dynamically casts each segment to its matching Ruby type or string.
Symbol constraints that are not built-in converter names (such as :alpha or :alnum) compile to POSIX character classes and return uncasted String parameters.
Typed parameter hashes containing Date, Gem::Version, Float, Symbol, and Integer instances serialize back into canonical URL paths via expand without requiring string conversion.

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