ChangeFeed: Fixes crts field being nullable

Microsoft.Azure.Cosmos.Encryption.Custom/tests/Microsoft.Azure.Cosmos.Encryption.Custom.Tests/Contracts/DotNetSDKEncryptionCustomAPI.net6.json

@@ -1182,4 +1182,4 @@
     }
   },
   "NestedTypes": {}
-}
+}

Microsoft.Azure.Cosmos/src/Resource/FullFidelity/ChangeFeedMetadata.cs

@@ -6,6 +6,7 @@ namespace Microsoft.Azure.Cosmos
 {
     using System;
     using System.Collections.Generic;
+    using System.Net;
     using Microsoft.Azure.Cosmos.Resource.FullFidelity;
     using Microsoft.Azure.Documents;
     using Newtonsoft.Json;
@@ -28,12 +29,34 @@ class ChangeFeedMetadata
         /// </summary>
         [System.Text.Json.Serialization.JsonIgnore]
         [Newtonsoft.Json.JsonIgnore]
-        public DateTime? ConflictResolutionTimestamp => this.ConflictResolutionTimestampInSeconds.HasValue ? UnixEpoch.AddSeconds(this.ConflictResolutionTimestampInSeconds.Value) : null;
+        public DateTime ConflictResolutionTimestamp => UnixEpoch.AddSeconds(this.ConflictResolutionTimestampInSeconds);
+
+        private double conflictResolutionTimestampInSeconds;
 
         [System.Text.Json.Serialization.JsonInclude]
         [System.Text.Json.Serialization.JsonPropertyName(ChangeFeedMetadataFields.ConflictResolutionTimestamp)]
-        [JsonProperty(PropertyName = ChangeFeedMetadataFields.ConflictResolutionTimestamp)]
-        internal double? ConflictResolutionTimestampInSeconds { get; set; }
+        [JsonProperty(PropertyName = ChangeFeedMetadataFields.ConflictResolutionTimestamp, Required = Required.Always)]
+        internal double ConflictResolutionTimestampInSeconds 
+        { 
+            get
+            {
+                if (this.conflictResolutionTimestampInSeconds == 0)
+                {
+                    throw new System.Text.Json.JsonException(
+                        $"{ChangeFeedMetadataFields.ConflictResolutionTimestamp} not set.");
+                }
+                return this.conflictResolutionTimestampInSeconds;
+            }
+            set
+            {
+                if (value == 0)
+                {
+                    throw new System.Text.Json.JsonException(
+                        $"{ChangeFeedMetadataFields.ConflictResolutionTimestamp} cannot be zero.");
+                }
+                this.conflictResolutionTimestampInSeconds = value;
+            }
+        }
 
         /// <summary>
         /// The current change's logical sequence number.

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/CFP/AllVersionsAndDeletes/BuilderWithCustomSerializerTests.cs

@@ -528,6 +528,48 @@ public void ValidateChangeFeedMetadataSerializationCreateWriteTest(bool property
                 actual: json);
         }
 
+        [TestMethod]
+        [Owner("trivediyash")]
+        [Description("Validates that ConflictResolutionTimestampInSeconds getter throws JsonException when value is zero.")]
+        public void ValidateConflictResolutionTimestampInSecondsGetterThrowsOnZeroTest()
+        {
+            ChangeFeedMetadata metadata = new()
+            {
+                Lsn = 374,
+                OperationType = ChangeFeedOperationType.Create
+            };
+
+            // Accessing the getter should throw JsonException when the value is zero (default)
+            System.Text.Json.JsonException exception = Assert.ThrowsException<System.Text.Json.JsonException>(() =>
+            {
+                double value = metadata.ConflictResolutionTimestampInSeconds;
+            });
+
+            Assert.IsTrue(exception.Message.Contains("crts"));
+            Assert.IsTrue(exception.Message.Contains("not set"));
+        }
+
+        [TestMethod]
+        [Owner("trivediyash")]
+        [Description("Validates that ConflictResolutionTimestampInSeconds setter throws JsonException when attempting to set zero.")]
+        public void ValidateConflictResolutionTimestampInSecondsSetterThrowsOnZeroTest()
+        {
+            ChangeFeedMetadata metadata = new()
+            {
+                Lsn = 374,
+                OperationType = ChangeFeedOperationType.Create
+            };
+
+            // Setting the value to zero should throw JsonException
+            System.Text.Json.JsonException exception = Assert.ThrowsException<System.Text.Json.JsonException>(() =>
+            {
+                metadata.ConflictResolutionTimestampInSeconds = 0;
+            });
+
+            Assert.IsTrue(exception.Message.Contains("crts"));
+            Assert.IsTrue(exception.Message.Contains("cannot be zero"));
+        }
+
         [TestMethod]
         [Timeout(300000)]
         [TestCategory("LongRunning")]

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/Contracts/DotNetPreviewSDKAPI.net6.json

@@ -162,18 +162,18 @@
           ],
           "MethodInfo": "System.Collections.Generic.Dictionary`2[System.String,System.Object] PartitionKey;CanRead:True;CanWrite:True;System.Collections.Generic.Dictionary`2[System.String,System.Object] get_PartitionKey();IsAbstract:False;IsStatic:False;IsVirtual:False;IsGenericMethod:False;IsConstructor:False;IsFinal:False;"
         },
-        "System.Nullable`1[System.DateTime] ConflictResolutionTimestamp[System.Text.Json.Serialization.JsonIgnoreAttribute()]-[Newtonsoft.Json.JsonIgnoreAttribute()]": {
+        "System.DateTime ConflictResolutionTimestamp[System.Text.Json.Serialization.JsonIgnoreAttribute()]-[Newtonsoft.Json.JsonIgnoreAttribute()]": {
           "Type": "Property",
           "Attributes": [
             "JsonIgnoreAttribute",
             "JsonIgnoreAttribute"
           ],
-          "MethodInfo": "System.Nullable`1[System.DateTime] ConflictResolutionTimestamp;CanRead:True;CanWrite:False;System.Nullable`1[System.DateTime] get_ConflictResolutionTimestamp();IsAbstract:False;IsStatic:False;IsVirtual:False;IsGenericMethod:False;IsConstructor:False;IsFinal:False;"
+          "MethodInfo": "System.DateTime ConflictResolutionTimestamp;CanRead:True;CanWrite:False;System.DateTime get_ConflictResolutionTimestamp();IsAbstract:False;IsStatic:False;IsVirtual:False;IsGenericMethod:False;IsConstructor:False;IsFinal:False;"
         },
-        "System.Nullable`1[System.DateTime] get_ConflictResolutionTimestamp()": {
+        "System.DateTime get_ConflictResolutionTimestamp()": {
           "Type": "Method",
           "Attributes": [],
-          "MethodInfo": "System.Nullable`1[System.DateTime] get_ConflictResolutionTimestamp();IsAbstract:False;IsStatic:False;IsVirtual:False;IsGenericMethod:False;IsConstructor:False;IsFinal:False;"
+          "MethodInfo": "System.DateTime get_ConflictResolutionTimestamp();IsAbstract:False;IsStatic:False;IsVirtual:False;IsGenericMethod:False;IsConstructor:False;IsFinal:False;"
         },
         "System.String get_Id()[System.Runtime.CompilerServices.CompilerGeneratedAttribute()]": {
           "Type": "Method",