Sample

Handle Sinatra error dispatch, status code handlers, show_exceptions modes, and route return value coercion without uncaught test exceptions, overwritten halt bodies, or symbol template lookups

sha256:6e3c39259c903ef98aa1a3a0b9b3c1dad0a3af159e7e3d689ce10e03f43cf009

Case

Goal

Handle Sinatra error dispatch, status code handlers, show_exceptions modes, and route return value coercion without uncaught test exceptions, overwritten halt bodies, or symbol template lookups HOW

Packages

sinatra 4.2.1 rack-test 2.2.0 rack 3.2.7 rack-protection 4.2.1 mustermann 3.1.1

Environment

ruby

Created

2026-08-17T01:20:49Z

Commonly assumed

Raising a custom exception in a route is handled by its error block in development mode while unhandled exceptions return 500 in test mode, halt bodies are never replaced by status handlers, and returning a Symbol or Integer sets the body or status identically to the status helper.

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

Contract

• assert in development mode default show_exceptions intercepts custom exceptions with an HTML backtrace rather than running the error handler
• assert setting show_exceptions to :after_handler executes custom error handlers while leaving unhandled exceptions to the debug page
• assert in test mode with raise_errors enabled, unhandled exceptions are re-raised out of the Rack call rather than returning 500
• assert defining an error 404 or not_found handler silently overwrites the custom body passed to halt 404
• assert returning a status code with a string body in a route is superseded by the registered status error handler
• assert returning a Symbol from a route block performs a template lookup and produces an empty body rather than setting the status code or string body
• assert returning an Integer from a route sets the HTTP status code and an empty body, including when status 201 is the final expression
• assert returning a Hash serves concatenated key-value array chunks as text/html rather than JSON
• assert pass throws to the next matching route within the same request instance, preserving instance variables while resetting route params

Files

• Gemfile
• Gemfile.lock
• NOTES.md
• csx.json
• src/app.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 · 2026-08-17 · ed25519:d91480838ac982c9