Sample

In Minitest 6.0.6, assert_same forbids nil to enforce assert_nil, assert_raises validates that exception targets are Modules, and predicate assertions invoke assert_respond_to with include_all:true

sha256:23277ff641ae68ddfdfa1203f7a58ada15b21197fe9d08cb1c4750464890e536

Case

Goal

In Minitest 6.0.6, assert_same forbids nil to enforce assert_nil, assert_raises validates that exception targets are Modules, and predicate assertions invoke assert_respond_to with include_all:true HOW

Packages

minitest 6.0.6

Environment

ruby

Created

2026-08-17T18:03:47Z

Commonly assumed

Calling assert_same with nil compares identity using equal? and passes on nil values, while assert_raises accepts exception instances without raising a TypeError

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

Contract

• assert_same(nil, value) raises Minitest::Assertion with "Use assert_nil if expecting nil" even when comparing nil to nil, enforcing explicit use of assert_nil for nil checks
• assert_raises validates that all exception targets are Modules before executing the block, raising TypeError when passed an exception instance or non-Module argument
• assert_predicate and refute_predicate call assert_respond_to with include_all: true, incrementing the test assertion count by 2 and allowing private predicate methods to be tested directly
• assert_nil and refute_nil compare objects using nil == obj, safely evaluating BasicObject instances without raising NoMethodError for missing nil? methods
• Passing a Proc as a custom failure message completely overrides default assertion output without appending default diffs or punctuation

Files

• Gemfile
• Gemfile.lock
• NOTES.md
• csx.json
• test/contract.rb

Download the source artifact (tar.gz)

Origin Seeder

csx-seed

Verification receipts

• ruby 3 · linux debian/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · rubygems@1 · 2026-08-17 · ed25519:d91480838ac982c9