feat(dart_frog): expand router http method support (#76)

Author: felangel

packages/dart_frog/lib/src/_internal.dart

@@ -2,6 +2,7 @@ import 'dart:convert';
 import 'dart:io';
 
 import 'package:dart_frog/dart_frog.dart';
+import 'package:http_methods/http_methods.dart' show isHttpMethod;
 import 'package:shelf/shelf.dart' as shelf;
 import 'package:shelf/shelf_io.dart' as shelf_io;
 

packages/dart_frog/lib/src/http_method.dart

@@ -8,6 +8,12 @@ enum HttpMethod {
   /// GET HTTP Method
   get('GET'),
 
+  /// HEAD HTTP Method
+  head('HEAD'),
+
+  /// OPTIONS HTTP Method
+  options('OPTIONS'),
+
   /// PATCH HTTP Method
   patch('PATCH'),
 

packages/dart_frog/lib/src/router.dart

@@ -18,6 +18,17 @@
 
 part of '_internal.dart';
 
+/// Middleware to remove body from request.
+Handler _removeBody(Handler handler) {
+  return (context) async {
+    var response = await handler(context);
+    if (response.headers.containsKey('content-length')) {
+      response = response.copyWith(headers: {'content-length': '0'});
+    }
+    return response.copyWith(body: <int>[]);
+  };
+}
+
 /// A class that routes requests to handlers based on HTTP verb and route
 /// pattern.
 class Router {
@@ -31,6 +42,27 @@ class Router {
   final List<RouterEntry> _routes = [];
   final Handler _notFoundHandler;
 
+  /// Add [handler] for [verb] requests to [route].
+  ///
+  /// If [verb] is `GET` the [handler] will also be called for `HEAD` requests
+  /// matching [route]. This is because handling `GET` requests without handling
+  /// `HEAD` is always wrong. To explicitely implement a `HEAD` handler it must
+  /// be registered before the `GET` handler.
+  void add(String verb, String route, Function handler) {
+    if (!isHttpMethod(verb)) {
+      throw ArgumentError.value(verb, 'verb', 'expected a valid HTTP method');
+    }
+
+    final _verb = verb.toUpperCase();
+
+    if (_verb == 'GET') {
+      // Handling in a 'GET' request without handling a 'HEAD' request is always
+      // wrong, thus, we add a default implementation that discards the body.
+      _routes.add(RouterEntry('HEAD', route, handler, middleware: _removeBody));
+    }
+    _routes.add(RouterEntry(_verb, route, handler));
+  }
+
   /// Handle all request to [route] using [handler].
   void all(String route, Function handler) {
     _routes.add(RouterEntry('ALL', route, handler));
@@ -86,6 +118,33 @@ class Router {
     return _notFoundHandler(context);
   }
 
+  // Handlers for all methods
+
+  /// Handle `GET` request to [route] using [handler].
+  ///
+  /// If no matching handler for `HEAD` requests is registered, such requests
+  /// will also be routed to the [handler] registered here.
+  void get(String route, Function handler) => add('GET', route, handler);
+
+  /// Handle `HEAD` request to [route] using [handler].
+  void head(String route, Function handler) => add('HEAD', route, handler);
+
+  /// Handle `POST` request to [route] using [handler].
+  void post(String route, Function handler) => add('POST', route, handler);
+
+  /// Handle `PUT` request to [route] using [handler].
+  void put(String route, Function handler) => add('PUT', route, handler);
+
+  /// Handle `DELETE` request to [route] using [handler].
+  void delete(String route, Function handler) => add('DELETE', route, handler);
+
+  /// Handle `OPTIONS` request to [route] using [handler].
+  void options(String route, Function handler) =>
+      add('OPTIONS', route, handler);
+
+  /// Handle `PATCH` request to [route] using [handler].
+  void patch(String route, Function handler) => add('PATCH', route, handler);
+
   static Response _defaultNotFound(RequestContext context) => routeNotFound;
 
   /// Sentinel [Response] object indicating that no matching route was found.

packages/dart_frog/pubspec.yaml

@@ -7,6 +7,7 @@ environment:
   sdk: ">=2.17.0 <3.0.0"
 
 dependencies:
+  http_methods: ^1.1.0
   shelf: ^1.1.0
   shelf_hotreload: ^1.1.0