Implement xsd:integer codec

CHANGELOG.md

@@ -32,3 +32,4 @@
 - Implement `xsd:double` codec
 - Implement `xsd:float` codec
 - Implement `xsd:unsignedInt` codec
+- Implement `xsd:integer` codec

README.md

@@ -34,7 +34,7 @@ This library aims to support the following XSD 1.1 built-in datatypes that are c
 |          `xsd:decimal` |      ✅      |        ✅        |    `Decimal`    |     `package:decimal`    |
 |           `xsd:double` |      ✅      |        ✅        |    `double`    |     `dart:core`    |
 |            `xsd:float` |      ✅      |        ✅        |    `double`    |     `dart:core`    |
-|          `xsd:integer` |      ✅      |        ❌        |    `BigInt`    |     `dart:core`    |
+|          `xsd:integer` |      ✅      |        ✅        |    `BigInt`    |     `dart:core`    |
 | `xsd:nonPositiveInteger` |      ✅      |        ✅        |    `BigInt`    |     `dart:core`    |
 | `xsd:negativeInteger` |      ✅      |        ❌        |    `BigInt`    |     `dart:core`    |
 | `xsd:long` |      ✅      |        ✅        |    `BigInt`    |     `dart:core`    |
@@ -77,7 +77,7 @@ This library aims to support the following XSD 1.1 built-in datatypes that are c
 ## Limitations
 
 * **Facets on Built-in Types**: This library focuses on implementing the XSD built-in datatypes as they are defined in the "XML Schema Part 2: Datatypes" specification. This includes their inherent properties, lexical spaces, value spaces, and any *fixed* facets that define them (e.g., the range of `xsd:byte` or the `whiteSpace` behavior of `xsd:token`).
-    * The library currently **does not** provide a mechanism to dynamically apply arbitrary constraining facets (like `minLength`, `maxLength`, `pattern`, `enumeration`, `totalDigits`, `fractionDigits` beyond what defines a base type) to create new, user-defined derived simple types *at runtime through the codec*. For instance, while `xsd:string` is supported, you cannot pass `maxLength="5"` to the `XsdStringCodec` to validate against this specific restriction dynamically. Such validation would typically be handled by a higher-level XSD schema processor that uses this library for the base datatype conversions.
+* The library currently **does not** provide a mechanism to dynamically apply arbitrary constraining facets (like `minLength`, `maxLength`, `pattern`, `enumeration`, `totalDigits`, `fractionDigits` beyond what defines a base type) to create new, user-defined derived simple types *at runtime through the codec*. For instance, while `xsd:string` is supported, you cannot pass `maxLength="5"` to the `XsdStringCodec` to validate against this specific restriction dynamically. Such validation would typically be handled by a higher-level XSD schema processor that uses this library for the base datatype conversions.
 
 ## Usage
 

lib/src/codecs/codecs.dart

@@ -28,3 +28,5 @@ export 'any_uri/any_uri_codec.dart';
 export 'decimal/decimal_codec.dart';
 export 'double/double_codec.dart';
 export 'float/float_codec.dart';
+export 'integer/integer_codec.dart';
+export 'unsigned_int/unsigned_int_codec.dart';

lib/src/codecs/integer/integer_codec.dart

@@ -0,0 +1,15 @@
+import 'dart:convert';
+
+import 'package:xsd/src/codecs/integer/integer_decoder.dart';
+import 'package:xsd/src/codecs/integer/integer_encoder.dart';
+
+/// A [Codec] that converts between XSD `integer` strings and [BigInt] objects.
+class XsdIntegerCodec extends Codec<BigInt, String> {
+  const XsdIntegerCodec();
+
+  @override
+  Converter<BigInt, String> get encoder => const XsdIntegerEncoder();
+
+  @override
+  Converter<String, BigInt> get decoder => const XsdIntegerDecoder();
+}

lib/src/codecs/integer/integer_decoder.dart

@@ -0,0 +1,18 @@
+import 'dart:convert';
+
+import '../../helpers/whitespace.dart';
+
+class XsdIntegerDecoder extends Converter<String, BigInt> {
+  const XsdIntegerDecoder();
+
+  @override
+  BigInt convert(String input) {
+    final trimmed = processWhiteSpace(input, Whitespace.collapse);
+
+    if (trimmed.isEmpty) {
+      throw const FormatException('The input string cannot be empty.');
+    }
+
+    return BigInt.parse(trimmed);
+  }
+}

lib/src/codecs/integer/integer_encoder.dart

@@ -0,0 +1,8 @@
+import 'dart:convert';
+
+class XsdIntegerEncoder extends Converter<BigInt, String> {
+  const XsdIntegerEncoder();
+
+  @override
+  String convert(BigInt input) => input.toString();
+}

test/codecs/integer_codec_test.dart

@@ -0,0 +1,26 @@
+import 'package:test/test.dart';
+import 'package:xsd/xsd.dart';
+
+void main() {
+  group('XsdIntegerCodec', () {
+    const codec = XsdIntegerCodec();
+
+    test('should encode valid integer', () {
+      expect(codec.encode(BigInt.from(123)), '123');
+      expect(codec.encode(BigInt.from(-123)), '-123');
+      expect(codec.encode(BigInt.zero), '0');
+    });
+
+    test('should decode valid integer', () {
+      expect(codec.decode('123'), BigInt.from(123));
+      expect(codec.decode('-123'), BigInt.from(-123));
+      expect(codec.decode('0'), BigInt.zero);
+      expect(codec.decode('  +123  '), BigInt.from(123));
+    });
+
+    test('should throw on invalid integer', () {
+      expect(() => codec.decode('12.3'), throwsFormatException);
+      expect(() => codec.decode('abc'), throwsFormatException);
+    });
+  });
+}