[dotnet] [bidi] Make cookie expiry as TimeSpan

dotnet/src/webdriver/BiDi/Communication/Broker.cs

@@ -84,6 +84,7 @@ internal Broker(BiDi bidi, Uri url)
                 new RealmConverter(_bidi),
                 new RealmTypeConverter(),
                 new DateTimeOffsetConverter(),
+                new TimeSpanConverter(),
                 new PrintPageRangeConverter(),
                 new InputOriginConverter(),
                 new WebExtensionConverter(_bidi),

dotnet/src/webdriver/BiDi/Communication/Json/Converters/DateTimeOffsetConverter.cs

@@ -27,16 +27,7 @@ internal class DateTimeOffsetConverter : JsonConverter<DateTimeOffset>
 {
     public override DateTimeOffset Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
     {
-        // Workaround: it should be Int64, chrome uses double for `expiry` like "expiry":1737379944.308351
-
-        if (reader.TryGetInt64(out long unixTime) is false)
-        {
-            var doubleValue = reader.GetDouble();
-
-            unixTime = Convert.ToInt64(doubleValue);
-        }
-
-        return DateTimeOffset.FromUnixTimeMilliseconds(unixTime);
+        return DateTimeOffset.FromUnixTimeMilliseconds(reader.GetInt64());
     }
 
     public override void Write(Utf8JsonWriter writer, DateTimeOffset value, JsonSerializerOptions options)

dotnet/src/webdriver/BiDi/Communication/Json/Converters/TimeSpanConverter.cs

@@ -0,0 +1,44 @@
+// <copyright file="TimeSpanConverter.cs" company="Selenium Committers">
+// Licensed to the Software Freedom Conservancy (SFC) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The SFC licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+// </copyright>
+
+using System;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace OpenQA.Selenium.BiDi.Communication.Json.Converters;
+
+internal class TimeSpanConverter : JsonConverter<TimeSpan>
+{
+    public override TimeSpan Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        if (reader.TryGetInt64(out long milliseconds) is false)
+        {
+            var doubleValue = reader.GetDouble();
+
+            milliseconds = Convert.ToInt64(doubleValue);
+        }
+
+        return TimeSpan.FromMilliseconds(milliseconds);
+    }
+
+    public override void Write(Utf8JsonWriter writer, TimeSpan value, JsonSerializerOptions options)
+    {
+        writer.WriteNumberValue(value.TotalMilliseconds);
+    }
+}

dotnet/src/webdriver/BiDi/Network/Cookie.cs

@@ -18,15 +18,10 @@
 // </copyright>
 
 using System;
-using System.Text.Json.Serialization;
 
 namespace OpenQA.Selenium.BiDi.Network;
 
-public sealed record Cookie(string Name, BytesValue Value, string Domain, string Path, long Size, bool HttpOnly, bool Secure, SameSite SameSite)
-{
-    [JsonInclude]
-    public DateTimeOffset? Expiry { get; internal set; }
-}
+public sealed record Cookie(string Name, BytesValue Value, string Domain, string Path, long Size, bool HttpOnly, bool Secure, SameSite SameSite, TimeSpan? Expiry);
 
 public enum SameSite
 {