Sample
Demonstrate how Equatable runtimeType and property identity affect generic and collection equality
sha256:5c27c62458688e4ad17910025eef68c78ea3ce05d37db332add13fcfe5ddc813
PUBLISHED
L3_CONTRACT_PASS
MIT-0
Execution evidence
Declared environment and signed verification runs are separated so you can see exactly what this sample proves.
Evidence basisSigned contract pass
Verification receipts1
Verification levelL3_CONTRACT_PASS
Declared environment
- Execution context
- dart
- Operating system
- linux
- Architecture
- x64
- Runtime
- dart
- Language
- dart
- Package manager
- pub
Verification-run environments
- Execution context
- dart 3
- Operating system
- linux debian · glibc
- Architecture
- x64
- Runtime
- dart 3
- Language
- dart
- Package manager
- pub
- Execution
- container · docker
CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · pub@1 · 2026-08-17
Case
- Goal
- Demonstrate how Equatable runtimeType and property identity affect generic and collection equality HOW
- Packages
-
equatable 2.1.0
- Environment
- dart
- Created
- 2026-08-17T03:53:35Z
Commonly assumed
Two generic Equatable instances with identical values are equal when one type argument is a subtype of the other, such as Box<num>(42) and Box<int>(42).
The sample's author recorded this as what a developer or model would expect here. The contract below is what actually ran.
Contract
- Two generic Equatable instances with identical values are not equal when type arguments differ across subtype boundaries, and their runtimeType-dependent hashCodes differ.
- Box<Object?> and Box<dynamic> holding the same value are not equal because Dart reifies dynamic and Object? as distinct runtime types.
- Non-generic Equatable classes holding generic collections with identical elements are equal across List<num> and List<int> because collection equality compares element values.
- Two distinct holders of the shared double.nan constant compare equal because Equatable checks identical property objects before numeric equality.
- A subclass inheriting identical props is not equal to its generic parent instance in either direction.
Files
- NOTES.md
- csx.json
- lib/generic_value.dart
- pubspec.lock
- pubspec.yaml
- test/contract.dart
Download the source artifact (tar.gz)
Origin Seeder
csx-seed
Verification receipts
- dart 3 · linux debian/x64 · docker · CONTAINER_RUN · compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS · pub@1 · 2026-08-17 · ed25519:d91480838ac982c9