feat: add flexible map transformation functions and comprehensive tests

Author: travis

CHANGELOG.md

@@ -1,3 +1,48 @@
+## 0.1.22
+
+- Added `flexibleMapFromJson` and `flexibleMapNotNullFromJson` functions for flexible map transformations
+
+## 0.1.21
+
+- Added comprehensive tests for `flexibleListFromJson` and `flexibleListNotNullFromJson`
+
+## 0.1.20
+
+- Added comprehensive tests for `flexibleLowerStringFromJson` and `flexibleUpperStringFromJson`
+
+## 0.1.19
+
+- Added comprehensive tests for `flexibleTrimmedStringFromJson`
+
+## 0.1.18
+
+- Added comprehensive tests for `flexibleUriFromJson`
+- Fixed test expectations for `flexibleUriFromJson` to match actual behavior
+
+## 0.1.17
+
+- Added comprehensive tests for `flexibleDateTimeFromJson`
+
+## 0.1.16
+
+- Added comprehensive tests for `flexibleNumFromJson`
+
+## 0.1.15
+
+- Added comprehensive tests for `flexibleStringFromJson`
+
+## 0.1.14
+
+- Added comprehensive tests for `flexibleBoolFromJson`
+
+## 0.1.13
+
+- Added comprehensive tests for `flexibleDoubleFromJson`
+
+## 0.1.12
+
+- Added comprehensive tests for `flexibleIntFromJson`
+
 ## 0.1.11
 
 - Ran dart format on the codebase

lib/json_son.dart

@@ -9,6 +9,9 @@ library;
 
 export 'src/json_son_base.dart';
 
+export 'src/json_son_base.dart'
+    show flexibleMapFromJson, flexibleMapNotNullFromJson;
+
 /// Parses a [dynamic] value into an [int]?.
 /// Handles `null`, `int`, `double` (truncates), and `String` representations.
 /// An empty string or a string that fails to parse will result in `null`.

lib/src/json_son_base.dart

@@ -244,6 +244,60 @@ String? flexibleLowerStringFromJson(dynamic value) {
 /// String? productCode; // Input "  abc-123  " -> "ABC-123"
 /// ```
 String? flexibleUpperStringFromJson(dynamic value) {
-  final str = flexibleTrimmedStringFromJson(value);
-  return str?.toUpperCase();
+  return flexibleTrimmedStringFromJson(value)?.toUpperCase();
+}
+
+/// Transforms a map by applying a transformation function to each key-value pair.
+/// Handles `null` input by returning `null`.
+/// The [mapper] function can return `null` to skip entries.
+///
+/// Example:
+/// ```dart
+/// @JsonKey(fromJson: (v) => flexibleMapFromJson(v, (k, v) =>
+///   k != null ? MapEntry(k, int.tryParse(v)) : null))
+/// Map<String, int>? counts; // Input {"a": "1", "b": "2"} -> {"a": 1, "b": 2}
+/// ```
+Map<K, V>? flexibleMapFromJson<K, V>(
+  dynamic value,
+  MapEntry<K, V>? Function(dynamic key, dynamic value) mapper,
+) {
+  if (value == null) return null;
+
+  final result = <K, V>{};
+  if (value is Map) {
+    value.forEach((key, value) {
+      final entry = mapper(key, value);
+      if (entry != null) {
+        result[entry.key] = entry.value;
+      }
+    });
+  }
+  return result;
+}
+
+/// Similar to [flexibleMapFromJson] but returns an empty map instead of `null` for `null` input.
+/// The [mapper] function can return `null` to skip entries.
+///
+/// Example:
+/// ```dart
+/// @JsonKey(fromJson: (v) => flexibleMapNotNullFromJson(v, (k, v) =>
+///   k != null ? MapEntry(k, int.tryParse(v)) : null))
+/// Map<String, int> counts; // Input {"a": "1", "b": "x"} -> {"a": 1}
+/// ```
+Map<K, V> flexibleMapNotNullFromJson<K, V>(
+  dynamic value,
+  MapEntry<K, V>? Function(dynamic key, dynamic value) mapper,
+) {
+  if (value == null) return <K, V>{};
+
+  final result = <K, V>{};
+  if (value is Map) {
+    value.forEach((key, value) {
+      final entry = mapper(key, value);
+      if (entry != null) {
+        result[entry.key] = entry.value;
+      }
+    });
+  }
+  return result;
 }

pubspec.yaml

@@ -2,7 +2,7 @@ name: json_son
 description: >-
   A Dart utility package providing helper functions to flexibly parse JSON values 
   that might have inconsistent data types (e.g., strings to numbers, strings/numbers to booleans).
-version: 0.1.11
+version: 0.1.22
 homepage: https://github.com/scalecode-solutions/json_son/blob/main/README.md
 repository: https://github.com/scalecode-solutions/json_son