feat: support Request method strings and priority hints

README.md

@@ -40,7 +40,7 @@ Future<void> main() async {
   final request = Request(
     Uri.parse('https://api.example.com/tasks'),
     RequestInit(
-      method: HttpMethod.post,
+      method: 'POST',
       headers: Headers({'content-type': 'application/json; charset=utf-8'}),
       body: '{"title":"rewrite ht"}',
     ),
@@ -119,7 +119,7 @@ Future<void> main() async {
   final body = block.Block(<Object>['hello'], type: 'text/plain');
   final request = Request(
     Uri.parse('https://example.com'),
-    RequestInit(method: HttpMethod.post, body: body),
+    RequestInit(method: 'POST', body: body),
   );
 
   print(await request.text());                  // hello

example/main.dart

@@ -6,7 +6,7 @@ Future<void> main() async {
   final request = Request(
     Uri.parse('https://api.example.com/tasks'),
     RequestInit(
-      method: HttpMethod.post,
+      method: 'POST',
       headers: Headers({'content-type': 'application/json; charset=utf-8'}),
       body: jsonEncode({'title': 'Ship ht', 'priority': 'high'}),
     ),

lib/src/fetch/request.dart

@@ -6,7 +6,8 @@ export 'request.native.dart'
         RequestCache,
         RequestRedirect,
         RequestReferrerPolicy,
-        RequestDuplex;
+        RequestDuplex,
+        RequestPriority;
 export 'request.native.dart'
     if (dart.library.js_interop) 'request.js.dart'
     if (dart.library.io) 'request.io.dart'

lib/src/fetch/request.io.dart

@@ -1,7 +1,6 @@
 import 'dart:io' as io;
 import 'dart:typed_data';
 
-import '../core/http_method.dart';
 import 'body.dart';
 import 'blob.dart';
 import 'form_data.native.dart';
@@ -122,9 +121,9 @@ class Request implements native.Request {
   }
 
   @override
-  HttpMethod get method {
+  String get method {
     return switch (_host) {
-      final HttpRequestHost host => HttpMethod.parse(host.value.method),
+      final HttpRequestHost host => host.value.method,
       final NativeRequestHost host => host.value.method,
     };
   }
@@ -137,6 +136,14 @@ class Request implements native.Request {
     };
   }
 
+  @override
+  native.RequestPriority get priority {
+    return switch (_host) {
+      final HttpRequestHost _ => native.RequestPriority.auto,
+      final NativeRequestHost host => host.value.priority,
+    };
+  }
+
   @override
   native.RequestRedirect get redirect {
     return switch (_host) {
@@ -243,6 +250,7 @@ class Request implements native.Request {
         integrity: integrity,
         keepalive: keepalive,
         duplex: duplex,
+        priority: priority,
       );
     }
 
@@ -253,7 +261,7 @@ class Request implements native.Request {
       HttpRequestHost() => Request(
         native.Request(
           url,
-          init(body: method.allowsRequestBody ? body?.clone() : null),
+          init(body: _allowsRequestBody(method) ? body?.clone() : null),
         ),
       ),
     };
@@ -295,6 +303,7 @@ class Request implements native.Request {
         integrity: init?.integrity ?? request.integrity,
         keepalive: init?.keepalive ?? request.keepalive,
         duplex: init?.duplex ?? request.duplex,
+        priority: init?.priority ?? request.priority,
       );
     }
 
@@ -314,13 +323,18 @@ class Request implements native.Request {
     return native.Request(request.url, requestInit(body: init?.body ?? body));
   }
 
-  static Body? _bodyFromWrappedRequest(Request request, HttpMethod method) {
-    if (!method.allowsRequestBody &&
+  static Body? _bodyFromWrappedRequest(Request request, String method) {
+    if (!_allowsRequestBody(method) &&
         request._host is HttpRequestHost &&
-        !request.method.allowsRequestBody) {
+        !_allowsRequestBody(request.method)) {
       return null;
     }
 
     return request.body;
   }
+
+  static bool _allowsRequestBody(String method) {
+    final upper = method.toUpperCase();
+    return upper != 'GET' && upper != 'HEAD';
+  }
 }

lib/src/fetch/request.js.dart

@@ -8,7 +8,6 @@ import 'package:web/web.dart' as web;
 
 import '../_internal/web_fetch_utils.dart' as web_fetch;
 import '../_internal/web_stream_bridge.dart';
-import '../core/http_method.dart';
 import 'body.dart';
 import 'blob.dart';
 import 'form_data.native.dart';
@@ -141,9 +140,9 @@ class Request implements native.Request {
   }
 
   @override
-  HttpMethod get method {
+  String get method {
     return switch (_host) {
-      final WebRequestHost host => HttpMethod.parse(host.value.method),
+      final WebRequestHost host => host.value.method,
       final NativeRequestHost host => host.value.method,
     };
   }
@@ -156,6 +155,14 @@ class Request implements native.Request {
     };
   }
 
+  @override
+  native.RequestPriority get priority {
+    return switch (_host) {
+      final WebRequestHost _ => native.RequestPriority.auto,
+      final NativeRequestHost host => host.value.priority,
+    };
+  }
+
   @override
   native.RequestRedirect get redirect {
     return switch (_host) {
@@ -286,6 +293,7 @@ class Request implements native.Request {
         integrity: integrity,
         keepalive: keepalive,
         duplex: duplex,
+        priority: priority,
       );
     }
 
@@ -332,6 +340,7 @@ class Request implements native.Request {
         integrity: init?.integrity ?? request.integrity,
         keepalive: init?.keepalive ?? request.keepalive,
         duplex: init?.duplex ?? request.duplex,
+        priority: init?.priority ?? request.priority,
       );
     }
 
@@ -374,6 +383,7 @@ class Request implements native.Request {
         integrity: init?.integrity ?? wrapped.integrity,
         keepalive: init?.keepalive ?? wrapped.keepalive,
         duplex: init?.duplex ?? wrapped.duplex,
+        priority: init?.priority ?? wrapped.priority,
       ),
     );
   }

lib/src/fetch/request.native.dart

@@ -1,6 +1,5 @@
 import 'dart:typed_data';
 
-import '../core/http_method.dart';
 import 'body.dart';
 import 'blob.dart';
 import 'form_data.native.dart';
@@ -73,6 +72,16 @@ enum RequestDuplex {
   final String value;
 }
 
+enum RequestPriority {
+  auto('auto'),
+  high('high'),
+  low('low');
+
+  const RequestPriority(this.value);
+
+  final String value;
+}
+
 sealed class _RequestInput {
   const _RequestInput();
 }
@@ -111,9 +120,10 @@ class RequestInit {
     this.integrity,
     this.keepalive,
     this.duplex,
+    this.priority,
   });
 
-  final HttpMethod? method;
+  final String? method;
   final HeadersInit? headers;
   final BodyInit? body;
   final String? referrer;
@@ -125,6 +135,7 @@ class RequestInit {
   final String? integrity;
   final bool? keepalive;
   final RequestDuplex? duplex;
+  final RequestPriority? priority;
 }
 
 /// Native request contract shell aligned with the MDN `Request` surface.
@@ -142,6 +153,7 @@ class Request {
       isHistoryNavigation = _isHistoryNavigationFromInput(input),
       keepalive = _keepaliveFromInput(input, init?.keepalive),
       mode = _modeFromInput(input, init?.mode),
+      priority = _priorityFromInput(input, init?.priority),
       redirect = _redirectFromInput(input, init?.redirect),
       referrer = _referrerFromInput(input, init?.referrer),
       referrerPolicy = _referrerPolicyFromInput(input, init?.referrerPolicy),
@@ -167,8 +179,9 @@ class Request {
   final String integrity;
   final bool isHistoryNavigation;
   final bool keepalive;
-  final HttpMethod method;
+  final String method;
   final RequestMode mode;
+  final RequestPriority priority;
   final RequestRedirect redirect;
   final String referrer;
   final RequestReferrerPolicy? referrerPolicy;
@@ -242,6 +255,7 @@ class Request {
         integrity: integrity,
         keepalive: keepalive,
         duplex: duplex,
+        priority: priority,
       ),
     );
   }
@@ -257,7 +271,7 @@ class Request {
   static Body? _bodyFromInput(
     _RequestInput input,
     BodyInit? init,
-    HttpMethod method,
+    String method,
   ) {
     if (init != null) {
       _validateRequestBodyMethod(method);
@@ -343,26 +357,44 @@ class Request {
     };
   }
 
-  static HttpMethod _methodFromInput(_RequestInput input, HttpMethod? init) {
-    if (init != null) return init;
+  static String _methodFromInput(_RequestInput input, String? init) {
+    if (init != null) return _normalizeMethod(init);
     return switch (input) {
       _RequestRequestInput(:final value) => value.method,
-      _ => HttpMethod.get,
+      _ => 'GET',
     };
   }
 
-  static void _validateRequestBodyMethod(HttpMethod method) {
-    if (method.allowsRequestBody) {
+  static void _validateRequestBodyMethod(String method) {
+    if (method != 'GET' && method != 'HEAD') {
       return;
     }
 
     throw ArgumentError.value(
       method,
       'method',
-      '${method.value} requests cannot have a body.',
+      '$method requests cannot have a body.',
     );
   }
 
+  static String _normalizeMethod(String method) {
+    if (!_methodPattern.hasMatch(method)) {
+      throw ArgumentError.value(method, 'method', 'Invalid HTTP method');
+    }
+
+    final upper = method.toUpperCase();
+    if (upper == 'CONNECT' || upper == 'TRACE' || upper == 'TRACK') {
+      throw ArgumentError.value(method, 'method', 'Forbidden HTTP method');
+    }
+
+    return switch (upper) {
+      'DELETE' || 'GET' || 'HEAD' || 'OPTIONS' || 'POST' || 'PUT' => upper,
+      _ => method,
+    };
+  }
+
+  static final _methodPattern = RegExp(r"^[!#$%&'*+\-.^_`|~0-9A-Za-z]+$");
+
   static RequestMode _modeFromInput(_RequestInput input, RequestMode? init) {
     if (init != null) return init;
     return switch (input) {
@@ -382,6 +414,17 @@ class Request {
     };
   }
 
+  static RequestPriority _priorityFromInput(
+    _RequestInput input,
+    RequestPriority? init,
+  ) {
+    if (init != null) return init;
+    return switch (input) {
+      _RequestRequestInput(:final value) => value.priority,
+      _ => RequestPriority.auto,
+    };
+  }
+
   static String _referrerFromInput(_RequestInput input, String? init) {
     if (init != null) return init;
     return switch (input) {

test/public_api_surface_test.dart

@@ -4,11 +4,15 @@ import 'package:test/test.dart';
 
 void main() {
   test('public API symbols are importable and usable', () async {
-    const method = HttpMethod.post;
+    const method = 'POST';
+    const protocolMethod = HttpMethod.post;
     const status = HttpStatus.ok;
     const version = HttpVersion.http11;
     final mime = MimeType.json;
-    final requestInit = RequestInit(method: method);
+    final requestInit = RequestInit(
+      method: method,
+      priority: RequestPriority.high,
+    );
     final responseInit = ResponseInit(status: status);
 
     final headers = Headers({'content-type': mime.toString()});
@@ -28,13 +32,14 @@ void main() {
 
     final Object init = 'x';
 
-    expect(method.toString(), 'POST');
+    expect(protocolMethod.toString(), 'POST');
     expect(version.value, 'HTTP/1.1');
     expect(mime.essence, 'application/json');
     expect(params.get('a'), '1');
     expect(await blob.text(), 'hello');
     expect(file.name, 'hello.txt');
-    expect(requestInit.method, HttpMethod.post);
+    expect(requestInit.method, 'POST');
+    expect(requestInit.priority, RequestPriority.high);
     expect(responseInit.status, 200);
     expect(request.headers.has('content-type'), isTrue);
     expect(await multipart.bytes(), isNotEmpty);