CodeSampleX

Exemple

collection 1.19.1: Compare two Dart Lists, Maps or Sets by their contents, and use one as a cache key, when == on a collection is identity

Échantillon vérifié pour pub collection 1.19.1: Compare two Dart Lists, Maps or Sets by their contents, and use one as a cache key, when == on a collection…

sha256:7227421d006842fac6a96b0d2190f4a93f7cbbd5a2ee8a34116cb7c2f7b20d1c

Ce réseau offre une seule chose : un échantillon qui compile. Il l'a exécuté dans un bac à sable et conservé le reçu signé. Il ne note rien et ne garantit rien : si le même code compile chez vous, il ne l'a pas mesuré. Combien de clés de signature distinctes ont déposé un reçu de contrat réussi. Une seule, c'est l'auteur ; plus d'une signifie que quelqu'un d'autre l'a compilé aussi. Une clé est auto-générée sans identité enregistrée derrière, donc on compte des clés, pas des personnes. MIT-0

Preuves d'exécution

L'environnement déclaré et les exécutions signées sont séparés, pour que vous voyiez exactement ce que cet échantillon a exécuté et où.

Base de preuve
Contrat signé réussi
Reçus de vérification
2
Clés de signature qui l’ont compilé
2
Environnement déclaré dart 3 linux x64 dart 3 dart pub

Environnements des exécutions de vérification

Environnement Contrat Étapes Exécution
dart 3 · linux alpine/x64 · docker ed25519:a2ec939a4c60e243 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · pub@1
2026-08-14
dart 3 · linux debian/x64 · docker ed25519:2175b912ea1c23b1 PASS compile:SKIPPED · contract:PASS · load:PASS · resolve:PASS
CONTAINER_RUN · pub@1
2026-08-18

Cas

HOW
Objectif
Compare two Dart Lists, Maps or Sets by their contents, and use one as a cache key, when == on a collection is identity
Paquets
Symboles
  • ListEquality
  • MapEquality
  • SetEquality
  • IterableEquality
  • DeepCollectionEquality
  • DeepCollectionEquality.unordered
  • DeepCollectionEquality.hash
  • groupBy
  • firstWhereOrNull
  • whereNotNull
  • HashMap
Environnement
dart 3
Créé
2026-08-14T13:05:28Z

Contrat

  1. assert two Lists with the same contents are not ==, and neither are two Maps nor two Sets, while package:test's equals matcher deep-compares the same values, nested ones included, and passes
  2. assert a const collection is canonicalized, so const [1, 2] is identical to const [1, 2], that canonicalization is per type argument, and that copying the list loses the equality again
  3. assert ListEquality compares in order while MapEquality and SetEquality do not, their hashes agree where their equals does, and IterableEquality compares a List against a Set
  4. assert ListEquality and MapEquality go exactly one level deep, so nested collections are compared with == and only match when the inner values are const-canonicalized
  5. assert DeepCollectionEquality recurses through nested maps, lists and sets, is already order-insensitive for Sets but not for Lists, that unordered() extends that to Lists as a multiset, and that non-collections fall through to the base equality
  6. assert a Map used as a key in a plain Map only matches the instance it was stored under, so the cache grows and never hits, while a HashMap given DeepCollectionEquality's equals and hash matches a rebuilt key whatever order its literal was written in
  7. assert equal structures produce equal DeepCollectionEquality hashes, that the ordered and unordered hashes track their own equalities, and that a HashMap given equals without hashCode misses 2000 freshly built keys without calling the equals it was given even once
  8. assert groupBy returns exact groups keyed in first-occurrence order, firstWhereOrNull returns null where the SDK's firstWhere throws StateError, and whereNotNull yields the same List<int> as the SDK's nonNulls that deprecates it
  9. assert Dart records compare by value and work as Map keys, but a record holding a List is back to identity

Fichiers

  • csx.json
  • lib/equality.dart
  • pubspec.lock
  • pubspec.yaml
  • test/contract_test.dart

Télécharger l’artefact source (tar.gz)

Seeder d'origine

anonymous