[gmpassos]

Fix: nested JSON lists decoded as lazily cast List<Map>

JsonDecoder.decode<Map> / decodeAsync<Map> (and decodeFromBytes*, fromJson*, fromJsonMap*, JsonCodec.decode*) decoded the values of an untyped Map with the Map TypeInfo itself. A nested JSON list therefore took Map as its element type and was wrapped by List.cast<Map>(): decoding succeeded, then reading (or adding) a non-Map element threw a TypeError far from the decode call. An untyped List/Set/Iterable had the same defect for its elements.

A collection type without arguments (Map, List, Set, Iterable) now decodes its values/elements as dynamic, so the result matches dart:convert's jsonDecode. Collections with arguments (Map<String, int>, List<User>) and entity types are unchanged.

Review follow-up: the first version of the fix also sent collections with arguments to dynamic, dropping Map<String, int> / Map<String, Entity> / List<Entity> decoding. Fixed in 5235232 with one shared rule (_untypedCollectionAsDynamic), plus regression tests (sync and async) that fail on the previous commit.

Behavior changes (documented in the CHANGELOG): nested lists under untyped collections are now List<dynamic> rather than List<Map>/List<List> views; type decoders keyed on Map/List no longer see the scalars nested under an untyped collection.

Tests

For the fix (JsonDecoder untyped collections groups): every decode entry point compared against jsonDecode — scalars, nulls, mixed types, map-first vs scalar-first, nested/empty lists, date-like strings, top-level lists, untyped Set/Iterable, a non-standard decoder (no raw fast path), JsonCodec, encode→decode round trips, 200-level nesting, a 1000-element mixed list, unusual keys, writes to decoded lists. The fix-specific tests fail on the old code.

Entity integration: new TestPayloadWithReflection (Map, Map<String, dynamic>, List<Map>, List<List>, List, dynamic fields) through every decode entry point, generated $fromJson/$fromJsonEncoded, round trips and lists of entities. Reflection records these fields with explicit dynamic arguments, so they were not affected by the bug; these tests guard that path.

General coverage:

• reflection_factory_json_paths_test.dart: async decoding with Future inputs/values, decoder/encoder hooks and their fallbacks, scalar parsing, callToJson, isStandard, MimeTypeResolverExtension.
• reflection_factory_paths_test.dart: MethodInvocation, optional positional parameters, JsonField accessors, EnumReflection, static field setters, constructor invocation errors.

Line coverage: reflection_factory_json.dart 86.9% → 95.9%, reflection_factory_base.dart 83.1% → 89.5%.

Dependencies

• dart_style: >=3.1.10 <3.1.11 → >=3.1.13 <3.1.14. Dart 3.13.2 bundles 3.1.13 (3.13.0–3.13.1 bundle 3.1.10), so the old pin no longer matched dart format.
• environment.sdk: >=3.13.0 → >=3.13.2, keeping the pin matched to the consumer's SDK (as in 2.9.0). Narrower SDK range → minor bump.
• analyzer: ^13.0.0 → ^14.5.0 (allowed by dart_style 3.1.13); no code changes needed.
• Lower bounds raised to resolved versions: build, mime, pub_semver, yaml, build_runner, build_test, pubspec_parse, data_serializer, test.

Regenerated code is unchanged apart from the version string (and the new test entity).

Verification

• dart analyze: no issues
• dart format --set-exit-if-changed lib test example: clean
• dart test: 520 passed (VM); changed test files also pass on Chrome

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.56%. Comparing base (72f80a4) to head (4902e34).
⚠️ Report is 6 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master      #56      +/-   ##
==========================================
+ Coverage   89.56%   92.56%   +2.99%     
==========================================
  Files          14       14              
  Lines        6423     6428       +5     
==========================================
+ Hits         5753     5950     +197     
+ Misses        670      478     -192     

Flag	Coverage Δ
unittests	92.56% <100.00%> (+2.99%)	⬆️

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