Sample
Sinatra 4 removes the IndifferentHash initializer that merged a hash argument, silently producing an empty hash with the argument as the default value instead
sha256:505354b2db0a9e15b3c1720605ee174c820a6c6345acea3e8f620bc078351ab0
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Case
- Goal
- Sinatra 4 removes the IndifferentHash initializer that merged a hash argument, silently producing an empty hash with the argument as the default value instead HOW
- Packages
- sinatra 4.2.1
- Environment
- ruby
- Created
- 2026-08-16T17:07:41Z
Commonly assumed
Sinatra::IndifferentHash.new({"role" => "admin"}) produces a populated hash where the string and symbol keys both resolve to "admin", matching the same pattern that worked in Sinatra 3
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- Sinatra::IndifferentHash.new({"role" => "admin", "id" => 7}) returns an empty hash of size 0 whose default value is the argument object, so ih["role"] returns the original seed hash rather than "admin" — the constructor no longer merges its argument in Sinatra 4
- ih.size == 0
- ih["role"] == seed_hash (returns default, not the value)
- ih[:role] == seed_hash (symbol access also returns the default)
- require 'rack/protection/encrypted_cookie' raises LoadError — EncryptedCookie was removed from rack-protection 4.x
- Rack::Protection.constants does not include :EncryptedCookie
- Sinatra::IndifferentHash['role', 'admin', 'id', 7] still populates the hash correctly — only .new(hash) is broken
Files
- Gemfile
- NOTES.md
- app.rb
- csx.json
- test/contract.rb
Download the verified artifact (tar.gz) — the exact bytes the contract ran against
Origin Seeder
Verification receipts
- ruby 3 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · rubygems@1 · 2026-08-16 · ed25519:d91480838ac982c9