サンプル

Configure JsonSerializable options and enum decoding fallbacks in json_annotation, proving snake_case key enforcement, unknownEnumValue null bypass, and readValue error attribution

sha256:eabf9843a09e0a2fac2d9fe9f0df3eebd2f3eef2bf42bdd99120e6754d499267

ケース

ゴール

Configure JsonSerializable options and enum decoding fallbacks in json_annotation, proving snake_case key enforcement, unknownEnumValue null bypass, and readValue error attribution HOW

パッケージ

json_annotation 4.9.0

環境

dart

作成日

2026-08-17T14:38:30Z

よくある思い込み

A model expects JsonSerializable.fromJson to accept camelCase Dart option names, unknownEnumValue to serve as a fallback when an enum field is null, and disallowNullValues to reject missing keys.

このサンプルの作者が、ここで開発者やモデルが期待するであろうこととして記録したもの。下の契約が実際に実行されたものだ。

コントラクト

• JsonSerializable.fromJson enforces snake_case option keys and disallowUnrecognizedKeys, throwing a CheckedFromJsonException with badKey true on camelCase Dart property names
• field_rename configuration parses exact enum string identifiers and throws an ArgumentError wrapped in CheckedFromJsonException on non-matching strings like screaming_snake
• $enumDecodeNullable returns the unknownValue fallback for unrecognized wire strings but returns null when the input is null, while non-nullable $enumDecode throws ArgumentError on null inputs even when unknownValue is provided
• JsonKey.nullForUndefinedEnumValue causes $enumDecodeNullable to map unrecognized wire strings to null, but passing an incompatible enum type throws an ArgumentError
• readValue custom extractors allow retrieving values from nested paths or aliases, and type mismatch exceptions are re-attributed to the target model field key in CheckedFromJsonException
• $checkKeys evaluates allowedKeys first, requiredKeys second, and disallowNullValues last, where disallowNullValues ignores completely absent keys unless combined with requiredKeys
• $checkedNew attaches the failing key name to CheckedFromJsonException for missing and disallowed-null keys, but leaves key as null for UnrecognizedKeysException

ファイル

• NOTES.md
• csx.json
• lib/account_config.dart
• pubspec.lock
• pubspec.yaml
• test/contract.dart

ソースアーティファクトをダウンロード (tar.gz)

オリジンシーダー

csx-seed

検証レシート

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