Test coverage

NATS.Jwt.Tests/Models/NatsJsonDateTimeOffsetConverterTests.cs

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+// Copyright (c) The NATS Authors.
+// Licensed under the Apache License, Version 2.0.
+
+using System;
+using System.IO;
+using System.Text.Json;
+using NATS.Jwt.Internal;
+using Xunit;
+
+namespace NATS.Jwt.Tests.Models;
+
+public class NatsJsonDateTimeOffsetConverterTests
+{
+    [Fact]
+    public void Read_UnsupportedType_ShouldThrowException()
+    {
+        // Act & Assert
+        var ex = Assert.Throws<InvalidOperationException>(() =>
+        {
+            // Arrange
+            var converter = new TestConverter();
+            var reader = new Utf8JsonReader(JsonSerializer.SerializeToUtf8Bytes(123));
+            reader.Read(); // Move to the first token
+            converter.Read(ref reader, typeof(DateTime), new JsonSerializerOptions());
+        });
+        Assert.Contains("Reading unknown date type", ex.Message);
+    }
+
+    [Fact]
+    public void Write_ValidValue_ShouldWriteCorrectly()
+    {
+        // Arrange
+        var converter = new TestConverter();
+        MemoryStream memoryStream = new();
+        var writer = new Utf8JsonWriter(memoryStream);
+        var value = new DateTimeOffset(2021, 1, 1, 0, 0, 0, TimeSpan.Zero);
+
+        // Act
+        converter.Write(writer, value, new JsonSerializerOptions());
+        writer.Flush();
+
+        // Assert
+        var json = System.Text.Encoding.UTF8.GetString(memoryStream.ToArray());
+        Assert.Equal("1609459200", json);
+    }
+
+    private class TestConverter : NatsJsonDateTimeOffsetConverter
+    {
+        public new void Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        {
+            base.Read(ref reader, typeToConvert, options);
+        }
+
+        public new void Write(Utf8JsonWriter writer, DateTimeOffset? value, JsonSerializerOptions options)
+        {
+            base.Write(writer, value, options);
+        }
+    }
+}