Sample

Disprove naive assumptions regarding Sinatra input domain edge behaviors across optional route groups, dot captures, query parameter bare/empty flags, splat immutability, missing-referer redirect fallbacks, and 204 response stripping

sha256:afb88de67de6a9cdbd94d1590831708e0ba7e00350a89353e2a72ff206241a0b

Case

Goal

Disprove naive assumptions regarding Sinatra input domain edge behaviors across optional route groups, dot captures, query parameter bare/empty flags, splat immutability, missing-referer redirect fallbacks, and 204 response stripping HOW

Packages

sinatra 4.2.1 rack-test 2.2.0 rack 3.2.7 rack-protection 4.2.1 mustermann 3.1.1 minitest 5.25.5

Environment

ruby

Created

2026-08-16T17:06:44Z

Commonly assumed

A competent developer expects bare query flags `?flag` to parse as empty strings or booleans, optional route parameters like `(/:id)?` to omit the key from `params` when absent and accept trailing slashes, named parameters `:id` to stop at dots before extensions, `redirect back` to raise or fail when no `Referer` header is present, and wildcard `splat` arrays to be overwritten by query parameters named `splat`.

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

Contract

• assert an omitted optional route parameter in (/:id)? populates params[:id] as nil with params.key?('id') true while trailing slash /users/ returns 404, bare query flags parse as nil rather than empty strings, and named route params capture across dots
• assert named route parameter :filename captures the entire dotted string archive.tar.gz whereas :name.:ext splits at the final dot
• assert route wildcard splat arrays take precedence over conflicting ?splat query parameters and remain arrays
• assert bare query parameter ?bare yields nil while ?empty= yields empty string and ?count=0 yields string '0'
• assert redirect back without HTTP_REFERER silently redirects to root / with status 302 rather than raising an error
• assert UTF-8 routes and percent-encoded multibyte emoji parameters match and decode into valid UTF-8 encoded strings
• assert status 204 No Content suppresses the returned string body and strips Content-Type and Content-Length headers

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 · 2026-08-16 · ed25519:d91480838ac982c9