Migrate cqrs to null-safety (#7)

* Set min SDK version to 2.12 prerelease

* Migrate cqrs to null-safety

* Bump version to 5.0.0 and add changelog note

* Remove meta from pubspec

* Use null-safety mockito and test

* Bump min SDK version

* Remove deprecated success parameter from CommandResult

Resolves #14.

* Add generated mocks and fix tests

* Push cqrs code coverage to 100%

* Bump http to null-safe version

* Fix http mocks

* Fix http version to ^

.github/workflows/cqrs-publish.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
 
     container:
-      image: google/dart:2.10
+      image: google/dart:2.12-beta
 
     defaults:
       run:
@@ -29,4 +29,4 @@ jobs:
           echo $CREDENTIALS > ~/.pub-cache/credentials.json
 
       - name: Publish
-        run: pub publish -f
+        run: dart pub publish -f

.github/workflows/cqrs-test.yml

@@ -19,7 +19,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        dart_release: ['2.10', '2.11-beta']
+        dart_release: ['2.12-beta']
 
     container:
       image: google/dart:${{ matrix.dart_release }}

packages/cqrs/CHANGELOG.md

@@ -1,3 +1,9 @@
+# 5.0.0-nullsafety.0
+
+- **Breaking:** Migrate to null-safety.
+- **Breaking:** Bump minimum Dart version to 2.12 prerelease.
+- **Breaking:** Remove deprecated `success` parameter from `CommandResult` constructor.
+
 # 4.1.1
 
 - Fix exception thrown when the query result is `null`.

packages/cqrs/lib/src/command_result.dart

@@ -16,17 +16,13 @@ import 'transport_types.dart';
 
 /// The result of running a [Command].
 class CommandResult {
-  const CommandResult(
-    this.errors, {
-    @Deprecated("Success is derived from the `errors` emptiness.") bool success,
-  }) : assert(errors != null);
+  const CommandResult(this.errors);
 
   /// Creates a success [CommandResult] without any errors.
   const CommandResult.success() : errors = const [];
 
   /// Creates a failed [CommandResult] and ensures it has errors.
-  CommandResult.failed(this.errors)
-      : assert(errors != null && errors.isNotEmpty);
+  CommandResult.failed(this.errors) : assert(errors.isNotEmpty);
 
   CommandResult.fromJson(Map<String, dynamic> json)
       : errors = (json['ValidationErrors'] as List)
@@ -50,9 +46,7 @@ class CommandResult {
 
 /// A validation error.
 class ValidationError {
-  const ValidationError(this.code, this.message)
-      : assert(code != null),
-        assert(message != null);
+  const ValidationError(this.code, this.message);
 
   ValidationError.fromJson(Map<String, dynamic> json)
       : code = json['ErrorCode'] as int,

packages/cqrs/lib/src/cqrs.dart

@@ -16,7 +16,6 @@ import 'dart:async';
 import 'dart:convert';
 
 import 'package:http/http.dart' as http;
-import 'package:meta/meta.dart';
 
 import 'command_result.dart';
 import 'cqrs_exception.dart';
@@ -41,11 +40,7 @@ class CQRS {
     this._apiUri, {
     Duration timeout = const Duration(seconds: 30),
     Map<String, String> headers = const {},
-  })  : assert(_client != null),
-        assert(_apiUri != null),
-        assert(timeout != null),
-        assert(headers != null),
-        _timeout = timeout,
+  })  : _timeout = timeout,
         _headers = headers;
 
   final http.Client _client;
@@ -64,9 +59,6 @@ class CQRS {
     Query<T> query, {
     Map<String, String> headers = const {},
   }) async {
-    assert(query != null);
-    assert(headers != null);
-
     final response = await _send(query, pathPrefix: 'query', headers: headers);
 
     if (response.statusCode == 200) {
@@ -75,7 +67,7 @@ class CQRS {
 
         // Fix for https://github.com/leancodepl/corelibrary/issues/193
         if (json == null) {
-          return null;
+          return null as T;
         }
 
         return query.resultFactory(json);
@@ -105,9 +97,6 @@ class CQRS {
     Command command, {
     Map<String, String> headers = const {},
   }) async {
-    assert(command != null);
-    assert(headers != null);
-
     final response = await _send(
       command,
       pathPrefix: 'command',
@@ -136,13 +125,9 @@ class CQRS {
 
   Future<http.Response> _send(
     CQRSMethod cqrsMethod, {
-    @required String pathPrefix,
+    required String pathPrefix,
     Map<String, String> headers = const {},
   }) async {
-    assert(cqrsMethod != null);
-    assert(pathPrefix != null);
-    assert(headers != null);
-
     return _client.post(
       _apiUri.resolve('$pathPrefix/${cqrsMethod.getFullName()}'),
       body: jsonEncode(cqrsMethod),

packages/cqrs/lib/src/cqrs_exception.dart

@@ -15,10 +15,10 @@
 import 'package:http/http.dart';
 
 class CQRSException implements Exception {
-  const CQRSException(this.response, [this.message]) : assert(response != null);
+  const CQRSException(this.response, [this.message]);
 
   final Response response;
-  final String message;
+  final String? message;
 
   @override
   String toString() {

packages/cqrs/pubspec.yaml

@@ -1,20 +1,20 @@
-name: cqrs
-version: 4.1.1
-homepage: https://github.com/leancodepl/flutter_corelibrary/tree/master/packages/cqrs
-repository: https://github.com/leancodepl/flutter_corelibrary
-description: >-
-  A library for convenient communication with CQRS-compatible backends, using
-  queries and commands.
-
-environment:
-  sdk: '>=2.10.0 <3.0.0'
-
-dependencies:
-  http: ^0.12.2
-  meta: ^1.2.3
-
-dev_dependencies:
-  lint: ^1.3.0
-  mockito: ^4.1.2
-  test: ^1.15.4
-  test_coverage: ^0.5.0
+name: cqrs
+version: 5.0.0-nullsafety.0
+homepage: https://github.com/leancodepl/flutter_corelibrary/tree/master/packages/cqrs
+repository: https://github.com/leancodepl/flutter_corelibrary
+description: >-
+  A library for convenient communication with CQRS-compatible backends, using
+  queries and commands.
+
+environment:
+  sdk: '>=2.12.0-0 <3.0.0'
+
+dependencies:
+  http: ^0.13.0-nullsafety.0
+
+dev_dependencies:
+  build_runner: ^1.10.13
+  lint: ^1.5.1
+  mockito: ^5.0.0-nullsafety.4
+  test: ^1.16.0-nullsafety.13
+  test_coverage: ^0.5.0

packages/cqrs/test/cqrs_test.dart

@@ -3,13 +3,17 @@ import 'package:cqrs/src/cqrs.dart';
 import 'package:cqrs/src/cqrs_exception.dart';
 import 'package:cqrs/src/transport_types.dart';
 import 'package:http/http.dart';
+import 'package:mockito/annotations.dart';
 import 'package:mockito/mockito.dart';
 import 'package:test/test.dart';
 
+import 'cqrs_test.mocks.dart';
+
+@GenerateMocks([Client])
 void main() {
   group('CQRS', () {
-    Client client;
-    CQRS cqrs;
+    late MockClient client;
+    late CQRS cqrs;
     setUp(() {
       client = MockClient();
       cqrs = CQRS(client, Uri.parse('https://example.org/api/'));
@@ -108,6 +112,23 @@ void main() {
         )).called(1);
       });
 
+      test('throws CQRSException on json decoding failure', () async {
+        mockClientPost(client, Response('this is not a valid json', 200));
+
+        final result = cqrs.run(ExampleCommand());
+
+        expect(
+          result,
+          throwsA(
+            isA<CQRSException>().having(
+              (e) => e.message,
+              'message',
+              startsWith('An error occured while decoding response body JSON:'),
+            ),
+          ),
+        );
+      });
+
       test('throws CQRSException when response code is other than 200 and 422',
           () {
         mockClientPost(client, Response('', 500));
@@ -130,22 +151,20 @@ void main() {
   });
 }
 
-void mockClientPost(Client client, Response response) {
+void mockClientPost(MockClient client, Response response) {
   when(client.post(
     any,
     body: anyNamed('body'),
     headers: anyNamed('headers'),
   )).thenAnswer((_) async => response);
 }
 
-class MockClient extends Mock implements Client {}
-
-class ExampleQuery extends Query<bool> {
+class ExampleQuery extends Query<bool?> {
   @override
   String getFullName() => 'ExampleQuery';
 
   @override
-  bool resultFactory(dynamic json) => json as bool;
+  bool? resultFactory(dynamic json) => json as bool?;
 
   @override
   Map<String, dynamic> toJson() => {};

packages/cqrs/test/cqrs_test.mocks.dart

@@ -0,0 +1,98 @@
+// Mocks generated by Mockito 5.0.0-nullsafety.7 from annotations
+// in cqrs/test/cqrs_test.dart.
+// Do not manually edit this file.
+
+import 'dart:async' as _i6;
+import 'dart:convert' as _i7;
+import 'dart:typed_data' as _i3;
+
+import 'package:http/src/base_request.dart' as _i8;
+import 'package:http/src/client.dart' as _i5;
+import 'package:http/src/response.dart' as _i2;
+import 'package:http/src/streamed_response.dart' as _i4;
+import 'package:mockito/mockito.dart' as _i1;
+
+// ignore_for_file: comment_references
+// ignore_for_file: unnecessary_parenthesis
+
+class _FakeResponse extends _i1.Fake implements _i2.Response {}
+
+class _FakeUint8List extends _i1.Fake implements _i3.Uint8List {}
+
+class _FakeStreamedResponse extends _i1.Fake implements _i4.StreamedResponse {}
+
+/// A class which mocks [Client].
+///
+/// See the documentation for Mockito's code generation for more information.
+class MockClient extends _i1.Mock implements _i5.Client {
+  MockClient() {
+    _i1.throwOnMissingStub(this);
+  }
+
+  @override
+  _i6.Future<_i2.Response> head(Uri? url, {Map<String, String>? headers}) =>
+      (super.noSuchMethod(Invocation.method(#head, [url], {#headers: headers}),
+              returnValue: Future.value(_FakeResponse()))
+          as _i6.Future<_i2.Response>);
+  @override
+  _i6.Future<_i2.Response> get(Uri? url, {Map<String, String>? headers}) =>
+      (super.noSuchMethod(Invocation.method(#get, [url], {#headers: headers}),
+              returnValue: Future.value(_FakeResponse()))
+          as _i6.Future<_i2.Response>);
+  @override
+  _i6.Future<_i2.Response> post(Uri? url,
+          {Map<String, String>? headers,
+          Object? body,
+          _i7.Encoding? encoding}) =>
+      (super.noSuchMethod(
+              Invocation.method(#post, [url],
+                  {#headers: headers, #body: body, #encoding: encoding}),
+              returnValue: Future.value(_FakeResponse()))
+          as _i6.Future<_i2.Response>);
+  @override
+  _i6.Future<_i2.Response> put(Uri? url,
+          {Map<String, String>? headers,
+          Object? body,
+          _i7.Encoding? encoding}) =>
+      (super.noSuchMethod(
+              Invocation.method(#put, [url],
+                  {#headers: headers, #body: body, #encoding: encoding}),
+              returnValue: Future.value(_FakeResponse()))
+          as _i6.Future<_i2.Response>);
+  @override
+  _i6.Future<_i2.Response> patch(Uri? url,
+          {Map<String, String>? headers,
+          Object? body,
+          _i7.Encoding? encoding}) =>
+      (super.noSuchMethod(
+              Invocation.method(#patch, [url],
+                  {#headers: headers, #body: body, #encoding: encoding}),
+              returnValue: Future.value(_FakeResponse()))
+          as _i6.Future<_i2.Response>);
+  @override
+  _i6.Future<_i2.Response> delete(Uri? url,
+          {Map<String, String>? headers,
+          Object? body,
+          _i7.Encoding? encoding}) =>
+      (super.noSuchMethod(
+              Invocation.method(#delete, [url],
+                  {#headers: headers, #body: body, #encoding: encoding}),
+              returnValue: Future.value(_FakeResponse()))
+          as _i6.Future<_i2.Response>);
+  @override
+  _i6.Future<String> read(Uri? url, {Map<String, String>? headers}) =>
+      (super.noSuchMethod(Invocation.method(#read, [url], {#headers: headers}),
+          returnValue: Future.value('')) as _i6.Future<String>);
+  @override
+  _i6.Future<_i3.Uint8List> readBytes(Uri? url,
+          {Map<String, String>? headers}) =>
+      (super.noSuchMethod(
+              Invocation.method(#readBytes, [url], {#headers: headers}),
+              returnValue: Future.value(_FakeUint8List()))
+          as _i6.Future<_i3.Uint8List>);
+  @override
+  _i6.Future<_i4.StreamedResponse> send(_i8.BaseRequest? request) =>
+      (super.noSuchMethod(Invocation.method(#send, [request]),
+              returnValue: Future.value(_FakeStreamedResponse()))
+          as _i6.Future<_i4.StreamedResponse>);
+}