Set default path=/ when removing cookie

src/Microsoft.AspNet.Http/ResponseCookies.cs

@@ -80,36 +80,7 @@ public void Append(string key, string value, CookieOptions options)
         /// <param name="key"></param>
         public void Delete(string key)
         {
-            var encodedKeyPlusEquals = UrlEncoder.Default.Encode(key) + "=";
-            Func<string, string, bool> predicate = (value, encKeyPlusEquals) => value.StartsWith(encKeyPlusEquals, StringComparison.OrdinalIgnoreCase);
-
-            StringValues deleteCookies = $"{encodedKeyPlusEquals}; expires=Thu, 01-Jan-1970 00:00:00 GMT";
-            var existingValues = Headers[HeaderNames.SetCookie];
-            if (StringValues.IsNullOrEmpty(existingValues))
-            {
-                Headers[HeaderNames.SetCookie] = deleteCookies;
-            }
-            else
-            {
-                var values = existingValues.ToArray();
-                var newValues = new List<string>();
-
-                for (var i = 0; i < values.Length; i++)
-                {
-                    if (!predicate(values[i], encodedKeyPlusEquals))
-                    {
-                        newValues.Add(values[i]);
-                    }
-                }
-
-                values = deleteCookies.ToArray();
-                for (var i = 0; i < values.Length; i++)
-                {
-                    newValues.Add(values[i]);
-                }
-
-                Headers[HeaderNames.SetCookie] = new StringValues(newValues.ToArray());
-            }
+            Delete(key, new CookieOptions() { Path = "/" });
         }
 
         /// <summary>

test/Microsoft.AspNet.Http.Tests/ResponseCookiesTest.cs

@@ -0,0 +1,46 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Xunit;
+using Microsoft.Net.Http.Headers;
+using Microsoft.AspNet.Http.Internal;
+
+namespace Microsoft.AspNet.Http.Tests
+{
+    public class ResponseCookiesTest
+    {
+        [Fact]
+        public void DeleteCookieShouldSetDefaultPath()
+        {
+            var headers = new HeaderDictionary();
+            var cookies = new ResponseCookies(headers);
+            var testcookie = "TestCookie";
+
+            cookies.Delete(testcookie);
+
+            var cookieHeaderValues = headers[HeaderNames.SetCookie];
+            Assert.Equal(1, cookieHeaderValues.Count);
+            Assert.StartsWith(testcookie, cookieHeaderValues[0]);
+            Assert.Contains("path=/", cookieHeaderValues[0]);
+            Assert.Contains("expires=Thu, 01 Jan 1970 00:00:00 GMT", cookieHeaderValues[0]);
+        }
+
+        [Fact]
+        public void NoParamsDeleteRemovesCookieCreatedByAdd()
+        {
+            var headers = new HeaderDictionary();
+            var cookies = new ResponseCookies(headers);
+            var testcookie = "TestCookie";
+
+            cookies.Append(testcookie, testcookie);
+            cookies.Delete(testcookie);
+
+            var cookieHeaderValues = headers[HeaderNames.SetCookie];
+            Assert.Equal(1, cookieHeaderValues.Count);
+            Assert.StartsWith(testcookie, cookieHeaderValues[0]);
+            Assert.Contains("path=/", cookieHeaderValues[0]);
+            Assert.Contains("expires=Thu, 01 Jan 1970 00:00:00 GMT", cookieHeaderValues[0]);
+        }
+
+    }
+}