Sample

Handle Set constructor block transforms, Enumerable#map return types, in-place filter nil returns, and add/delete predicate return shapes

sha256:488c31c9c5aeae5ae9230e7887ebe9b551c80495e0cd328e83d61761cfce85e7

Case

Goal

Handle Set constructor block transforms, Enumerable#map return types, in-place filter nil returns, and add/delete predicate return shapes HOW

Packages

set 1.1.1

Environment

ruby

Created

2026-08-17T02:46:10Z

Commonly assumed

Passing a block to Set.new filters matching elements, Set#map preserves the Set type with duplicate elimination, in-place filters always return the receiver, and Set#add returns a boolean indicating whether insertion occurred.

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

Contract

• assert Set.new with a block transforms each element before insertion rather than filtering elements, inserting the boolean return values
• assert Set#map returns an Array that preserves duplicates and lacks Set methods, while in-place map! mutates the receiver into a Set
• assert Set#select! and Set#reject! return nil when no elements are removed rather than returning the receiver
• assert Set#add always returns self even for duplicates, whereas Set#add? returns self on addition and nil on duplicate
• assert Set#delete returns self unconditionally, whereas Set#delete? returns nil when the element is absent
• assert Set#flatten only unpacks nested Set instances, leaving nested Array instances intact
• assert Set#=== tests element inclusion for pattern matching, while Set equality with Array is always false

Files

• Gemfile
• Gemfile.lock
• NOTES.md
• csx.json
• 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