Added #

• New options.page_width / options.trailing_commas for json_annotation_lenient:auto_default — dart_style's public DartFormatter API never reads a project's analysis_options.yaml formatter: section at all (that logic is private to dart_style's own CLI), so generated .g.dart previously always used dart_style's built-in defaults regardless of your project's configured page width or trailing-comma style. Set these explicitly to match.
• The builder now also auto-detects formatter: page_width:/ trailing_commas: from the nearest analysis_options.yaml (walking up from the project root) when options.page_width/options.trailing_commas aren't set explicitly — a from-scratch, simplified reimplementation that follows a single local (non-package:) include: path per file. An analysis_options.yaml whose formatter: section lives behind a package: include isn't picked up; use the explicit options in that case. An explicit options: value always wins over auto-detection.

Changed #

• Behavior change: autoDefaultJsonBuilder now defaults explicit_to_json to true when a consuming project's build.yaml doesn't set it at all (nested @JsonSerializable fields need it to serialize correctly almost all the time, and the stock json_serializable default of false meant every consumer had to opt in by hand). If your project relies on the old implicit-toJson behavior for nested objects, add explicit_to_json: false explicitly under this builder's options: — an explicit value in either direction is always honored; this only fills the gap when the key is absent.

Fixed #

• LenientBoolConverter now accepts numeric double values and normalizes string input case-insensitively ("TRUE", "Yes", ...); an unrecognized string now throws instead of silently returning false, matching every other converter.
• LenientIntConverter now accepts decimal strings ("42.5") via a double fallback, and throws instead of producing a bogus int for non-finite (NaN/Infinity) input.
• LenientDateTimeConverter no longer misreads an 8-digit yyyyMMdd string (e.g. "20240101") as an epoch-seconds timestamp; out-of-range epoch values now throw instead of raising an unrelated RangeError.
• All converters raise English FormatExceptions naming the offending value's runtime type, instead of a Chinese-only message with no type info.
• The options.lenient yml no longer accepts a double literal for an int default (it produced code that failed to compile); double defaults are now always rendered with an explicit .0.
• The builder now warns at build time when @LenientConverter/ options.lenient is active on a library that doesn't import package:json_annotation_lenient/json_annotation_lenient.dart (a yml-only setup needs that import; without it the generated code fails with an undefined-name error) and skips the converter rewrite for that library rather than emitting code that won't compile.
• @DisableLenient() / a field-level @LenientConverter(...) on an inherited field is now honored — previously only the class's own fields were scanned.
• The json['x'] == null ? d : const Converter().fromJson(json['x']) fold now only applies to our own Lenient*Converter classes, so it no longer rewrites a third-party JsonConverter into a call shape it may not support.
• Set<T> fields are now covered by the same auto-default rewrite as List<T> (.toSet() alongside .toList()).

Performance #

• The generated-source rewrite now applies all edits in a single StringBuffer pass instead of repeated String.replaceRange calls (previously O(edits × file size) per build).

Docs #

• Removed a builders: block from both READMEs' build.yaml example — it registered a second builder that collided with this package's own (auto_apply: none) declaration and would fail build_runner with a "conflicting outputs" error.
• Fixed stale lib/tool/build/... / lib/utils/... path references in dartdoc comments (pre-restructuring paths that don't exist in this package).
• environment.sdk lowered floor corrected to ^3.11.0 to match what analyzer/build/dart_style actually require — the previous ^3.5.0 advertised a compatibility this package couldn't deliver.

Builder #

• New options.lenient section in build.yaml: turn leniency on/off per scalar type (int/double/num/bool/string/dateTime) project-wide, and override each type's fallback default value — no annotation needed on the model classes at all.

  options:
    lenient:
      int:
        enabled: true
        defaultValue: 0
      string:
        enabled: true
        defaultValue: ""
      dateTime:
        enabled: false
        utc: false
  

  Every key is optional; only what you write is applied. Precedence, highest first: a field's own @LenientConverter(...) → the yml enabled: → the class-level @LenientConverter(...). @DisableLenient() still opts a field out of everything. For default values: a field's @JsonKey(defaultValue:) → the yml defaultValue: → the built-in type default.

• dateTime accepts enabled:/utc: but not defaultValue: (DateTime has no const constructor); a defaultValue: written there is ignored rather than an error. Malformed entries anywhere in the lenient: section are skipped instead of failing the build.

• A yml defaultValue: also replaces the plain auto-default injected into non-lenient fields (json['x'] as String? ?? '<yours>').

• A class with no @LenientConverter/@DisableLenient annotation at all is now still processed, so a yml-only setup works.

Initial release.

Extracted from an app's internal json_serializable tooling into a standalone package.

Converters #

• LenientIntConverter / LenientDoubleConverter / LenientNumConverter / LenientBoolConverter / LenientStringConverter — accept a small set of common alternate JSON shapes (numeric strings, "true"/"1", mismatched numeric subtypes, ...) instead of throwing, with a per-field fallback default.
• LenientDateTimeConverter — accepts ISO 8601 strings, a few non-standard string formats (/ date separator, space instead of T), and epoch numbers whose unit (seconds/milliseconds/microseconds) is guessed from magnitude; dateTimeUtc controls how timezone-less values are interpreted.
• @LenientConverter(...) class-level annotation to turn on leniency for every field of a given scalar type at once; @DisableLenient() to opt a single field out entirely.

Builder #

• autoDefaultJsonBuilder (package:json_annotation_lenient/builder.dart) — a build_runner builder that replaces the stock json_serializable builder. Auto-fills type-based defaults ('', 0, 0.0, false, const [], const {}) for non-nullable fields with no explicit @JsonKey(defaultValue:), and rewrites matching fields to route through the Lenient*Converter classes when a class/field opts in via @LenientConverter.