Migrate to null safety (flutter#99)

Author: natebosch

.travis.yml

@@ -1,23 +1,35 @@
 language: dart
 
 dart:
-  - 2.3.0
-  - stable 
+  - dev
 
-dart_task:
-  - test: -p vm
-  - test: -p chrome
-  - dartanalyzer: --fatal-warnings --fatal-infos .
-
-matrix:
+jobs:
   include:
-  # Only validate formatting using the dev release
-  - dart: dev
-    dart_task: dartfmt
+    - stage: analyze_and_format
+      name: "Analyze"
+      os: linux
+      script: dartanalyzer --fatal-warnings --fatal-infos .
+    - stage: analyze_and_format
+      name: "Format"
+      os: linux
+      script: dartfmt -n --set-exit-if-changed .
+    - stage: test
+      name: "Vm Tests"
+      os: linux
+      script: pub run --enable-experiment=non-nullable test -p vm
+    - stage: test
+      name: "Web Tests"
+      os: linux
+      script: pub run --enable-experiment=non-nullable test -p chrome
+
+stages:
+  - analyze_and_format
+  - test
+
 
 # Only building master means that we don't run two builds for each pull request.
 branches:
-  only: [master]
+  only: [master, null_safety]
 
 cache:
   directories:

CHANGELOG.md

@@ -1,3 +1,14 @@
+## 2.2.0-nullsafety
+
+Pre-release for the null safety migration of this package.
+
+Note that 2.2.0 may not be the final stable null safety release version, we
+reserve the right to release it as a 3.0.0 breaking change.
+
+This release will be pinned to only allow pre-release sdk versions starting from
+2.10.0-2.0.dev, which is the first version where this package will appear in the
+null safety allow list.
+
 ## 2.1.5
 
 * Improve example and package description to address package site maintenance

analysis_options.yaml

@@ -2,6 +2,10 @@ include: package:pedantic/analysis_options.yaml
 analyzer:
   strong-mode:
     implicit-casts: false
+
+  enable-experiment:
+  - non-nullable
+
 linter:
   rules:
     - avoid_empty_else

example/example.dart

@@ -10,7 +10,7 @@ import 'package:crypto/crypto.dart';
 final _usage = 'Usage: dart hash.dart <md5|sha1|sha256> <input_filename>';
 
 Future main(List<String> args) async {
-  if (args == null || args.length != 2) {
+  if (args.length != 2) {
     print(_usage);
     exitCode = 64; // Command was used incorrectly.
     return;

lib/src/digest_sink.dart

@@ -7,24 +7,21 @@ import 'digest.dart';
 /// A sink used to get a digest value out of `Hash.startChunkedConversion`.
 class DigestSink extends Sink<Digest> {
   /// The value added to the sink, if any.
-  Digest get value {
-    assert(_value != null);
-    return _value;
-  }
+  Digest get value => _value;
 
-  Digest _value;
+  late final Digest _value;
 
   /// Adds [value] to the sink.
   ///
   /// Unlike most sinks, this may only be called once.
   @override
   void add(Digest value) {
-    assert(_value == null);
     _value = value;
   }
 
   @override
   void close() {
-    assert(_value != null);
+    // Ensure late final field was assigned before closing.
+    assert((_value as dynamic) != null);
   }
 }

lib/src/hmac.dart

@@ -60,7 +60,7 @@ class _HmacSink extends ByteConversionSink {
   final _innerResultSink = DigestSink();
 
   /// The sink for the inner hash computation.
-  ByteConversionSink _innerSink;
+  late final ByteConversionSink _innerSink;
 
   /// Whether [close] has been called.
   bool _isClosed = false;

pubspec.yaml

@@ -1,16 +1,20 @@
 name: crypto
-version: 2.1.5
+version: 2.2.0-nullsafety
 description: Implementations of SHA, MD5, and HMAC cryptographic functions
 homepage: https://www.github.com/dart-lang/crypto
 
 environment:
-  sdk: '>=2.3.0 <3.0.0'
+  sdk: '>=2.10.0-2.0.dev <2.10.0'
 
 dependencies:
-  collection: '^1.0.0'
-  convert: '>=1.0.0 <3.0.0'
-  typed_data: '^1.0.0'
+  collection: ^1.15.0-nullsafety
+  convert: ^2.2.0-nullsafety
+  typed_data: ^1.3.0-nullsafety
 
 dev_dependencies:
-  pedantic: ^1.0.0
-  test: ^1.0.0
+  pedantic: ^1.10.0-nullsafety
+  test: ^1.16.0-nullsafety
+
+dependency_overrides:
+  convert:
+    git: git://github.com/dart-lang/convert.git

test/hmac_sha2_test.dart

@@ -103,13 +103,13 @@ void main() {
 }
 
 void testCase({
-  String name,
-  String key,
-  String data,
-  String hmacSha224,
-  String hmacSha256,
-  String hmacSha384,
-  String hmacSha512,
+  required String name,
+  required String key,
+  required String data,
+  required String hmacSha224,
+  required String hmacSha256,
+  required String hmacSha384,
+  required String hmacSha512,
   bool truncation = false,
 }) {
   test(name, () {

test/sha_monte_test.dart

@@ -65,7 +65,7 @@ void monteTest(String name, Hash hash, String seed, List<String> expected) {
         md0 = (Uint8List.fromList(_seed));
         md1 = (Uint8List.fromList(_seed));
         md2 = (Uint8List.fromList(_seed));
-        Digest mdI;
+        late Digest mdI;
         for (var i = 3; i < 1003; i++) {
           var mI = [...md0, ...md1, ...md2];
           mdI = hash.convert(mI);

test/utils.dart

@@ -18,7 +18,7 @@ final toupleMatch = RegExp('([0-9a-fA-F]{2})');
 Uint8List bytesFromHexString(String message) {
   var bytes = <int>[];
   for (var match in toupleMatch.allMatches(message)) {
-    bytes.add(int.parse(match.group(0), radix: 16));
+    bytes.add(int.parse(match.group(0)!, radix: 16));
   }
   return Uint8List.fromList(bytes);
 }