Add CookieBuilder

Author: Nate McMaster

src/Microsoft.AspNetCore.Http.Abstractions/CookieBuilder.cs

@@ -0,0 +1,93 @@
+// 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 System;
+
+namespace Microsoft.AspNetCore.Http
+{
+    /// <summary>
+    /// Defines settings used to create a cookie.
+    /// </summary>
+    public class CookieBuilder
+    {
+        /// <summary>
+        /// The name of the cookie.
+        /// </summary>
+        public virtual string Name { get; set; }
+
+        /// <summary>
+        /// The cookie path.
+        /// </summary>
+        /// <remarks>
+        /// Determines the value that will set on <seealso cref="CookieOptions.Path"/>.
+        /// </remarks>
+        public virtual string Path { get; set; }
+
+        /// <summary>
+        /// The domain to associate the cookie with.
+        /// </summary>
+        /// <remarks>
+        /// Determines the value that will set on <seealso cref="CookieOptions.Domain"/>.
+        /// </remarks>
+        public virtual string Domain { get; set; }
+
+        /// <summary>
+        /// Indicates whether a cookie is accessible by client-side script.
+        /// </summary>
+        /// <remarks>
+        /// Determines the value that will set on <seealso cref="CookieOptions.HttpOnly"/>.
+        /// </remarks>
+        public virtual bool HttpOnly { get; set; }
+
+        /// <summary>
+        /// The SameSite attribute of the cookie. The default value is <see cref="SameSiteMode.Lax"/>
+        /// </summary>
+        /// <remarks>
+        /// Determines the value that will set on <seealso cref="CookieOptions.SameSite"/>.
+        /// </remarks>
+        public virtual SameSiteMode SameSite { get; set; } = SameSiteMode.Lax;
+
+        /// <summary>
+        /// The policy that will be used to determine <seealso cref="CookieOptions.Secure"/>.
+        /// This is determined from the <see cref="HttpContext"/> passed to <see cref="Build(HttpContext)"/>.
+        /// </summary>
+        public virtual CookieSecurePolicy SecurePolicy { get; set; }
+
+
+        /// <summary>
+        /// Gets or sets the lifespan of a cookie.
+        /// </summary>
+        public virtual TimeSpan? Expiration { get; set; }
+
+        /// <summary>
+        /// Creates the cookie options from the given <paramref name="context"/>.
+        /// </summary>
+        /// <param name="context">The <see cref="HttpContext"/>.</param>
+        /// <returns>The cookie options.</returns>
+        public virtual CookieOptions Build(HttpContext context) => Build(context, DateTimeOffset.Now);
+
+        /// <summary>
+        /// Creates the cookie options from the given <paramref name="context"/> with an expiration based on <paramref name="expiresFrom"/> and <see cref="Expiration"/>.
+        /// </summary>
+        /// <param name="context">The <see cref="HttpContext"/>.</param>
+        /// <param name="expiresFrom">The time to use as the base for computing <seealso cref="CookieOptions.Expires" />.</param>
+        /// <returns>The cookie options.</returns>
+        public virtual CookieOptions Build(HttpContext context, DateTimeOffset expiresFrom)
+        {
+            if (context == null)
+            {
+                throw new ArgumentNullException(nameof(context));
+            }
+
+            return new CookieOptions
+            {
+                Path = Path ?? "/",
+                SameSite = SameSite,
+                HttpOnly = HttpOnly,
+                Domain = Domain,
+                Secure = SecurePolicy == CookieSecurePolicy.Always || (SecurePolicy == CookieSecurePolicy.SameAsRequest && context.Request.IsHttps),
+                Expires = Expiration.HasValue ? expiresFrom.Add(Expiration.Value) : default(DateTimeOffset?)
+            };
+        }
+    }
+}

src/Microsoft.AspNetCore.Http.Features/CookieOptions.cs

@@ -42,7 +42,6 @@ public CookieOptions()
         /// <returns>true to transmit the cookie only over an SSL connection (HTTPS); otherwise, false.</returns>
         public bool Secure { get; set; }
 
-
         /// <summary>
         /// Gets or sets the value for the SameSite attribute of the cookie. The default value is <see cref="SameSiteMode.Lax"/>
         /// </summary>

test/Microsoft.AspNetCore.Http.Abstractions.Tests/CookieBuilderTests.cs

@@ -0,0 +1,47 @@
+// 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 System;
+using Xunit;
+
+namespace Microsoft.AspNetCore.Http.Abstractions.Tests
+{
+    public class CookieBuilderTests
+    {
+        [Theory]
+        [InlineData(CookieSecurePolicy.Always, false, true)]
+        [InlineData(CookieSecurePolicy.Always, true, true)]
+        [InlineData(CookieSecurePolicy.SameAsRequest, true, true)]
+        [InlineData(CookieSecurePolicy.SameAsRequest, false, false)]
+        [InlineData(CookieSecurePolicy.None, true, false)]
+        [InlineData(CookieSecurePolicy.None, false, false)]
+        public void ConfiguresSecurePolicy(CookieSecurePolicy policy, bool requestIsHttps, bool secure)
+        {
+            var builder = new CookieBuilder
+            {
+                SecurePolicy = policy
+            };
+            var context = new DefaultHttpContext();
+            context.Request.IsHttps = requestIsHttps;
+            var options = builder.Build(context);
+
+            Assert.Equal(secure, options.Secure);
+        }
+
+        [Fact]
+        public void ComputesExpiration()
+        {
+            Assert.Null(new CookieBuilder().Build(new DefaultHttpContext()).Expires);
+
+            var now = DateTimeOffset.Now;
+            var options = new CookieBuilder { Expiration = TimeSpan.FromHours(1) }.Build(new DefaultHttpContext(), now);
+            Assert.Equal(now.AddHours(1), options.Expires);
+        }
+
+        [Fact]
+        public void CookieBuilderPreservesDefaultPath()
+        {
+            Assert.Equal(new CookieOptions().Path, new CookieBuilder().Build(new DefaultHttpContext()).Path);
+        }
+    }
+}