Enable null safety (#472)

Author: kevmoo

.travis.yml

@@ -1,23 +1,35 @@
 language: dart
 
 dart:
-  - dev
-  - 2.4.0
+- dev
 
-dart_task:
-  - test: --platform vm,chrome
-  - dartanalyzer: --fatal-infos --fatal-warnings .
-
-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 --enable-experiment=non-nullable --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]
 
 cache:
- directories:
-   - $HOME/.pub-cache
+  directories:
+  - $HOME/.pub-cache

CHANGELOG.md

@@ -1,3 +1,16 @@
+## 0.13.0-nullsafety-dev
+
+Pre-release for the null safety migration of this package.
+
+Note that 0.12.3 may not be the final stable null safety release version, we
+reserve the right to release it as a 0.13.0 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.
+
+- Added `const` constructor to `ByteStream`.
+
 ## 0.12.2
 
 * Fix error handler callback type for response stream errors to avoid masking

analysis_options.yaml

@@ -1,7 +1,11 @@
 include: package:pedantic/analysis_options.yaml
+
 analyzer:
   strong-mode:
     implicit-casts: false
+  enable-experiment:
+  - non-nullable
+
 linter:
   rules:
   - annotate_overrides

lib/http.dart

@@ -30,7 +30,7 @@ export 'src/streamed_response.dart';
 /// the same server, you should use a single [Client] for all of those requests.
 ///
 /// For more fine-grained control over the request, use [Request] instead.
-Future<Response> head(url, {Map<String, String> headers}) =>
+Future<Response> head(Object url, {Map<String, String>? headers}) =>
     _withClient((client) => client.head(url, headers: headers));
 
 /// Sends an HTTP GET request with the given headers to the given URL, which can
@@ -41,7 +41,7 @@ Future<Response> head(url, {Map<String, String> headers}) =>
 /// the same server, you should use a single [Client] for all of those requests.
 ///
 /// For more fine-grained control over the request, use [Request] instead.
-Future<Response> get(url, {Map<String, String> headers}) =>
+Future<Response> get(Object url, {Map<String, String>? headers}) =>
     _withClient((client) => client.get(url, headers: headers));
 
 /// Sends an HTTP POST request with the given headers and body to the given URL,
@@ -63,8 +63,8 @@ Future<Response> get(url, {Map<String, String> headers}) =>
 ///
 /// For more fine-grained control over the request, use [Request] or
 /// [StreamedRequest] instead.
-Future<Response> post(url,
-        {Map<String, String> headers, body, Encoding encoding}) =>
+Future<Response> post(Object url,
+        {Map<String, String>? headers, Object? body, Encoding? encoding}) =>
     _withClient((client) =>
         client.post(url, headers: headers, body: body, encoding: encoding));
 
@@ -87,8 +87,8 @@ Future<Response> post(url,
 ///
 /// For more fine-grained control over the request, use [Request] or
 /// [StreamedRequest] instead.
-Future<Response> put(url,
-        {Map<String, String> headers, body, Encoding encoding}) =>
+Future<Response> put(Object url,
+        {Map<String, String>? headers, Object? body, Encoding? encoding}) =>
     _withClient((client) =>
         client.put(url, headers: headers, body: body, encoding: encoding));
 
@@ -111,8 +111,8 @@ Future<Response> put(url,
 ///
 /// For more fine-grained control over the request, use [Request] or
 /// [StreamedRequest] instead.
-Future<Response> patch(url,
-        {Map<String, String> headers, body, Encoding encoding}) =>
+Future<Response> patch(Object url,
+        {Map<String, String>? headers, Object? body, Encoding? encoding}) =>
     _withClient((client) =>
         client.patch(url, headers: headers, body: body, encoding: encoding));
 
@@ -124,7 +124,7 @@ Future<Response> patch(url,
 /// the same server, you should use a single [Client] for all of those requests.
 ///
 /// For more fine-grained control over the request, use [Request] instead.
-Future<Response> delete(url, {Map<String, String> headers}) =>
+Future<Response> delete(Object url, {Map<String, String>? headers}) =>
     _withClient((client) => client.delete(url, headers: headers));
 
 /// Sends an HTTP GET request with the given headers to the given URL, which can
@@ -140,7 +140,7 @@ Future<Response> delete(url, {Map<String, String> headers}) =>
 ///
 /// For more fine-grained control over the request and response, use [Request]
 /// instead.
-Future<String> read(url, {Map<String, String> headers}) =>
+Future<String> read(Object url, {Map<String, String>? headers}) =>
     _withClient((client) => client.read(url, headers: headers));
 
 /// Sends an HTTP GET request with the given headers to the given URL, which can
@@ -156,7 +156,7 @@ Future<String> read(url, {Map<String, String> headers}) =>
 ///
 /// For more fine-grained control over the request and response, use [Request]
 /// instead.
-Future<Uint8List> readBytes(url, {Map<String, String> headers}) =>
+Future<Uint8List> readBytes(Object url, {Map<String, String>? headers}) =>
     _withClient((client) => client.readBytes(url, headers: headers));
 
 Future<T> _withClient<T>(Future<T> Function(Client) fn) async {

lib/src/base_client.dart

@@ -18,40 +18,42 @@ import 'streamed_response.dart';
 /// maybe [close], and then they get various convenience methods for free.
 abstract class BaseClient implements Client {
   @override
-  Future<Response> head(url, {Map<String, String> headers}) =>
+  Future<Response> head(Object url, {Map<String, String>? headers}) =>
       _sendUnstreamed('HEAD', url, headers);
 
   @override
-  Future<Response> get(url, {Map<String, String> headers}) =>
+  Future<Response> get(Object url, {Map<String, String>? headers}) =>
       _sendUnstreamed('GET', url, headers);
 
   @override
-  Future<Response> post(url,
-          {Map<String, String> headers, body, Encoding encoding}) =>
+  Future<Response> post(Object url,
+          {Map<String, String>? headers, Object? body, Encoding? encoding}) =>
       _sendUnstreamed('POST', url, headers, body, encoding);
 
   @override
-  Future<Response> put(url,
-          {Map<String, String> headers, body, Encoding encoding}) =>
+  Future<Response> put(Object url,
+          {Map<String, String>? headers, Object? body, Encoding? encoding}) =>
       _sendUnstreamed('PUT', url, headers, body, encoding);
 
   @override
-  Future<Response> patch(url,
-          {Map<String, String> headers, body, Encoding encoding}) =>
+  Future<Response> patch(Object url,
+          {Map<String, String>? headers, Object? body, Encoding? encoding}) =>
       _sendUnstreamed('PATCH', url, headers, body, encoding);
 
   @override
-  Future<Response> delete(url, {Map<String, String> headers}) =>
+  Future<Response> delete(Object url, {Map<String, String>? headers}) =>
       _sendUnstreamed('DELETE', url, headers);
+
   @override
-  Future<String> read(url, {Map<String, String> headers}) async {
+  Future<String> read(Object url, {Map<String, String>? headers}) async {
     final response = await get(url, headers: headers);
     _checkResponseSuccess(url, response);
     return response.body;
   }
 
   @override
-  Future<Uint8List> readBytes(url, {Map<String, String> headers}) async {
+  Future<Uint8List> readBytes(Object url,
+      {Map<String, String>? headers}) async {
     final response = await get(url, headers: headers);
     _checkResponseSuccess(url, response);
     return response.bodyBytes;
@@ -69,8 +71,8 @@ abstract class BaseClient implements Client {
 
   /// Sends a non-streaming [Request] and returns a non-streaming [Response].
   Future<Response> _sendUnstreamed(
-      String method, url, Map<String, String> headers,
-      [body, Encoding encoding]) async {
+      String method, url, Map<String, String>? headers,
+      [body, Encoding? encoding]) async {
     var request = Request(method, _fromUriOrString(url));
 
     if (headers != null) request.headers.addAll(headers);

lib/src/base_request.dart

@@ -4,6 +4,8 @@
 
 import 'dart:collection';
 
+import 'package:meta/meta.dart';
+
 import 'byte_stream.dart';
 import 'client.dart';
 import 'streamed_response.dart';
@@ -29,10 +31,10 @@ abstract class BaseRequest {
   ///
   /// This defaults to `null`, which indicates that the size of the request is
   /// not known in advance. May not be assigned a negative value.
-  int get contentLength => _contentLength;
-  int _contentLength;
+  int? get contentLength => _contentLength;
+  int? _contentLength;
 
-  set contentLength(int value) {
+  set contentLength(int? value) {
     if (value != null && value < 0) {
       throw ArgumentError('Invalid content length $value.');
     }
@@ -93,16 +95,17 @@ abstract class BaseRequest {
   /// Freezes all mutable fields and returns a single-subscription [ByteStream]
   /// that emits the body of the request.
   ///
-  /// The base implementation of this returns null rather than a [ByteStream];
+  /// The base implementation of this returns an empty [ByteStream];
   /// subclasses are responsible for creating the return value, which should be
   /// single-subscription to ensure that no data is dropped. They should also
   /// freeze any additional mutable fields they add that don't make sense to
   /// change after the request headers are sent.
+  @mustCallSuper
   ByteStream finalize() {
     // TODO(nweiz): freeze headers
     if (finalized) throw StateError("Can't finalize a finalized Request.");
     _finalized = true;
-    return null;
+    return const ByteStream(Stream.empty());
   }
 
   /// Sends this request.

lib/src/base_response.dart

@@ -10,18 +10,18 @@ import 'base_request.dart';
 /// they're returned by [BaseClient.send] or other HTTP client methods.
 abstract class BaseResponse {
   /// The (frozen) request that triggered this response.
-  final BaseRequest request;
+  final BaseRequest? request;
 
   /// The HTTP status code for this response.
   final int statusCode;
 
   /// The reason phrase associated with the status code.
-  final String reasonPhrase;
+  final String? reasonPhrase;
 
   /// The size of the response body, in bytes.
   ///
   /// If the size of the request is not known in advance, this is `null`.
-  final int contentLength;
+  final int? contentLength;
 
   // TODO(nweiz): automatically parse cookies from headers
 
@@ -42,7 +42,7 @@ abstract class BaseResponse {
       this.reasonPhrase}) {
     if (statusCode < 100) {
       throw ArgumentError('Invalid status code $statusCode.');
-    } else if (contentLength != null && contentLength < 0) {
+    } else if (contentLength != null && contentLength! < 0) {
       throw ArgumentError('Invalid content length $contentLength.');
     }
   }

lib/src/browser_client.dart

@@ -52,16 +52,17 @@ class BrowserClient extends BaseClient {
     request.headers.forEach(xhr.setRequestHeader);
 
     var completer = Completer<StreamedResponse>();
+
+    // TODO(kevmoo): Waiting on  https://github.com/dart-lang/linter/issues/2185
+    // ignore: void_checks
     unawaited(xhr.onLoad.first.then((_) {
-      // TODO(nweiz): Set the response type to "arraybuffer" when issue 18542
-      // is fixed.
-      var blob = xhr.response as Blob ?? Blob([]);
+      var blob = xhr.response as Blob;
       var reader = FileReader();
 
       reader.onLoad.first.then((_) {
         var body = reader.result as Uint8List;
         completer.complete(StreamedResponse(
-            ByteStream.fromBytes(body), xhr.status,
+            ByteStream.fromBytes(body), xhr.status!,
             contentLength: body.length,
             request: request,
             headers: xhr.responseHeaders,
@@ -76,6 +77,8 @@ class BrowserClient extends BaseClient {
       reader.readAsArrayBuffer(blob);
     }));
 
+    // TODO(kevmoo): Waiting on  https://github.com/dart-lang/linter/issues/2185
+    // ignore: void_checks
     unawaited(xhr.onError.first.then((_) {
       // Unfortunately, the underlying XMLHttpRequest API doesn't expose any
       // specific information about the error itself.

lib/src/byte_stream.dart

@@ -8,7 +8,7 @@ import 'dart:typed_data';
 
 /// A stream of chunks of bytes representing a single piece of data.
 class ByteStream extends StreamView<List<int>> {
-  ByteStream(Stream<List<int>> stream) : super(stream);
+  const ByteStream(Stream<List<int>> stream) : super(stream);
 
   /// Returns a single-subscription byte stream that will emit the given bytes
   /// in a single chunk.