Migrate canonical_json to null-safety

Author: jonasfj

canonical_json/CHANGELOG.md

@@ -1,3 +1,6 @@
+## v1.1.0
+ * Migrated to null-safety.
+
 ## v1.0.0
  * Initial release.
 

canonical_json/lib/canonical_json.dart

@@ -83,4 +83,4 @@ export 'src/exceptions.dart' show InvalidCanonicalJsonException;
 ///   }
 /// }
 /// ```
-const Codec<Object, List<int>> canonicalJson = CanonicalJsonCodec();
+const Codec<Object?, List<int>> canonicalJson = CanonicalJsonCodec();

canonical_json/lib/src/codec.dart

@@ -16,7 +16,7 @@ import 'dart:convert' show Codec;
 import 'decoder.dart' show CanonicalJsonDecoder;
 import 'encoder.dart' show CanonicalJsonEncoder;
 
-class CanonicalJsonCodec extends Codec<Object, List<int>> {
+class CanonicalJsonCodec extends Codec<Object?, List<int>> {
   const CanonicalJsonCodec();
 
   @override

canonical_json/lib/src/decoder.dart

@@ -18,9 +18,9 @@ import 'utils.dart' show char, RawMapEntry, ensureUint8List;
 import 'exceptions.dart' show InvalidCanonicalJsonException;
 import 'fast_unorm.dart' show fastNfc;
 
-class CanonicalJsonDecoder extends Converter<List<int>, Object> {
+class CanonicalJsonDecoder extends Converter<List<int>, Object?> {
   @override
-  Object convert(List<int> input) {
+  Object? convert(List<int> input) {
     ArgumentError.checkNotNull(input, 'input');
     final data = ensureUint8List(input);
     return Decoder(data).decode();
@@ -42,7 +42,7 @@ bool _isAscii(String s) => s.split('').every((c) => char(c) < 128);
 
 class _RawMapEntry extends RawMapEntry {
   final int offset;
-  _RawMapEntry(Uint8List key, Object value, this.offset) : super(key, value);
+  _RawMapEntry(Uint8List key, Object? value, this.offset) : super(key, value);
 }
 
 class Decoder {
@@ -70,21 +70,21 @@ class Decoder {
     }
   }
 
-  InvalidCanonicalJsonException _fail(String message, [int offset]) =>
+  InvalidCanonicalJsonException _fail(String message, [int? offset]) =>
       _InvalidCanonicalJsonException(_data, offset ?? _offset, message);
 
   int get _value => _offset < _data.length ? _data[_offset] : -1;
   int get _peak => _offset + 1 < _data.length ? _data[_offset + 1] : -1;
 
-  Object decode() {
+  Object? decode() {
     final result = _readValue();
     if (_data.length != _offset) {
       throw _fail('expected end of input');
     }
     return result;
   }
 
-  Object _readValue() {
+  Object? _readValue() {
     // 1-9, leading zeros are not allowed
     if (char('1') <= _value && _value <= char('9')) {
       return _readInt();
@@ -168,8 +168,8 @@ class Decoder {
   }
 
   /// Read a list, assumes _value is `[`.
-  List<Object> _readList() {
-    final result = <Object>[];
+  List<Object?> _readList() {
+    final result = <Object?>[];
     assert(_value == char('['));
     _offset++;
     if (_try(']')) {
@@ -183,7 +183,7 @@ class Decoder {
   }
 
   /// Read a map, assumes value is `{`.
-  Map<String, Object> _readMap() {
+  Map<String, Object?> _readMap() {
     assert(_value == char('{'));
     _offset++;
     if (_try('}')) {
@@ -207,7 +207,7 @@ class Decoder {
       }
     }
     // Create object from entries and validate utf-8 encoding of keys.
-    final result = <String, Object>{};
+    final result = <String, Object?>{};
     for (final entry in entries) {
       result[_decodeString(entry.key, entry.offset)] = entry.value;
     }

canonical_json/lib/src/encoder.dart

@@ -18,16 +18,16 @@ import 'package:typed_data/typed_data.dart' show Uint8Buffer;
 import 'utils.dart' show char, RawMapEntry;
 import 'fast_unorm.dart' show fastNfc;
 
-class CanonicalJsonEncoder extends Converter<Object, Uint8List> {
+class CanonicalJsonEncoder extends Converter<Object?, Uint8List> {
   @override
-  Uint8List convert(Object input) {
+  Uint8List convert(Object? input) {
     final result = Uint8Buffer();
     _encode(result, input, input);
     return Uint8List.view(result.buffer, 0, result.length);
   }
 }
 
-void _encode(Uint8Buffer output, Object input, Object original) {
+void _encode(Uint8Buffer output, Object? input, Object? original) {
   // Handle null, true, false
   if (input == null) {
     output.addAll(ascii.encode('null'));
@@ -70,7 +70,7 @@ void _encode(Uint8Buffer output, Object input, Object original) {
   }
 
   // Handle lists by calling recursively.
-  if (input is List<Object>) {
+  if (input is List<Object?>) {
     output.add(char('['));
     for (var i = 0; i < input.length; i++) {
       if (i > 0) {
@@ -83,7 +83,7 @@ void _encode(Uint8Buffer output, Object input, Object original) {
   }
 
   // Handle maps from string to anything.
-  if (input is Map<String, Object>) {
+  if (input is Map<String, Object?>) {
     final entries = RawMapEntry.fromMap(input).toList();
     entries.sort(RawMapEntry.compare);
     output.add(char('{'));

canonical_json/lib/src/utils.dart

@@ -28,12 +28,12 @@ int char(String character) {
 
 class RawMapEntry {
   final Uint8List key;
-  final Object value;
+  final Object? value;
   RawMapEntry(this.key, this.value) {
     assert(key != null);
   }
 
-  static Iterable<RawMapEntry> fromMap(Map<String, Object> map) sync* {
+  static Iterable<RawMapEntry> fromMap(Map<String, Object?> map) sync* {
     for (final e in map.entries) {
       final s = fastNfc(e.key).replaceAll(r'\', r'\\').replaceAll('"', r'\"');
       final b = utf8.encode(s);
@@ -46,7 +46,6 @@ class RawMapEntry {
   }
 
   static int compare(RawMapEntry a, RawMapEntry b) {
-    assert(a != null && b != null, 'a and b should never be null');
     final N = math.min(a.key.length, b.key.length);
     for (var i = 0; i < N; i++) {
       final r = a.key[i].compareTo(b.key[i]);

canonical_json/pubspec.yaml

@@ -1,5 +1,5 @@
 name: canonical_json
-version: 1.0.0
+version: 1.1.0
 description: |
   Encoder and decoder for a canonical JSON format, useful when cryptographically
   hashing or signing JSON objects.
@@ -8,9 +8,9 @@ repository: https://github.com/google/dart-neats.git
 issue_tracker: https://github.com/google/dart-neats/labels/pkg:canonical_json
 dependencies:
   typed_data: ^1.1.6
-  unorm_dart: ^0.1.1
+  unorm_dart: ^0.2.0
 dev_dependencies:
   test: ^1.5.1
   pedantic: ^1.4.0
 environment:
-  sdk: '>=2.0.0 <3.0.0'
+  sdk: '>=2.12.0 <3.0.0'

canonical_json/test/canonical_json_test.dart

@@ -75,7 +75,9 @@ void main() {
         expect(decoded, equals(value));
         final encodedAgain = canonicalJson.encode(decoded);
         expect(encodedAgain, encoded);
-        final decodedJson = json.fuse(utf8).decode(encoded);
+        // TODO: Use json.fuse(utf8) when: http://dartbug.com/46205 is fixed!
+        // final decodedJson = json.fuse(utf8).decode(encoded);
+        final decodedJson = json.decode(utf8.decode(encoded));
         expect(decodedJson, equals(value));
       }));