Sample
Prove that non-string hash keys can disappear silently when JSON stringifies keys before parsing.
sha256:ba97e97ecda15df826536164d19fb790db2821d0d91ae3dfb2f344205cfb43a0
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Case
- Goal
- Prove that non-string hash keys can disappear silently when JSON stringifies keys before parsing. HOW
- Packages
- json 2.9.1
- Environment
- ruby
- Created
- 2026-08-17T01:17:10Z
Commonly assumed
A Hash with keys 1 and '1' should preserve both entries after a round-trip because the two keys are different in Ruby.
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- JSON.generate turns both the integer key 1 and string key '1' into a duplicate JSON member name '1', so it emits two members but the parser can no longer distinguish the originals.
- JSON.parse(JSON.generate({1=>"num", "1"=>"str"})) returns {"1"=>"str"} because the second duplicate wins.
- JSON.parse(JSON.generate({1=>"num", "1"=>"str"}), symbolize_names: true) returns {"1":"str"} and still exposes only one key.
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
Verification receipts
- ruby 3 · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · rubygems@1 · 2026-08-17 · ed25519:d91480838ac982c9