CamEvent deserialization tests

TeslaCam.Data/CamClip.cs

@@ -1,6 +1,5 @@
 using System.Globalization;
 using System.Text;
-using System.Text.Json;
 using System.Text.RegularExpressions;
 
 namespace TeslaCam.Data;
@@ -45,19 +44,13 @@ public static IEnumerable<CamClip> GetClipFolders(string rootDirectory)
         }
     }
 
-    private static readonly JsonSerializerOptions JsonSerializerOptions = new()
-    {
-        NumberHandling = System.Text.Json.Serialization.JsonNumberHandling.AllowReadingFromString,
-    };
-
     public static CamEvent GetEventData(string filePath)
     {
         if (!File.Exists(filePath))
             return null;
 
         var json = File.ReadAllText(filePath);
-        var camEvent = JsonSerializer.Deserialize<CamEvent>(json, JsonSerializerOptions);
-        return camEvent;
+        return CamEvent.Deserialize(json);
     }
 
     public override string ToString()

TeslaCam.Data/CamEvent.cs

@@ -1,24 +1,42 @@
-using System.Text.Json.Serialization;
+using System.Text.Json;
+using System.Text.Json.Serialization;
 
 namespace TeslaCam.Data;
 
 public record class CamEvent
 {
     [JsonPropertyName("timestamp")]
-    public DateTime Timestamp { get; set; }
+    public required DateTime Timestamp { get; init; }
 
     [JsonPropertyName("city")]
-    public string City { get; set; }
+    public string City { get; init; }
 
     [JsonPropertyName("est_lat")]
-    public decimal EstLat { get; set; }
+    public decimal EstLat { get; init; }
 
     [JsonPropertyName("est_lon")]
-    public decimal EstLon { get; set; }
+    public decimal EstLon { get; init; }
 
     [JsonPropertyName("reason")]
-    public string Reason { get; set; }
+    public string Reason { get; init; }
 
     [JsonPropertyName("camera")]
-    public int Camera { get; set; }
+    public int Camera { get; init; }
+
+    private static readonly JsonSerializerOptions JsonSerializerOptions = new()
+    {
+        NumberHandling = JsonNumberHandling.AllowReadingFromString,
+    };
+
+    public static CamEvent Deserialize(string json)
+    {
+        try
+        {
+            return JsonSerializer.Deserialize<CamEvent>(json, JsonSerializerOptions);
+        }
+        catch (JsonException)
+        {
+            return null;
+        }
+    }
 }

TeslaCam.Tests/CamEventTests.cs

@@ -0,0 +1,93 @@
+using FluentAssertions;
+using TeslaCam.Data;
+
+namespace TeslaCam.Tests;
+
+public static class CamEventTests
+{
+    [Fact]
+    public static void Deserializes_Correctly()
+    {
+        // Arrange
+        var json = """
+        {
+            "timestamp":"2023-06-03T15:54:27",
+            "city":"Taylor",
+            "est_lat":"30.6075",
+            "est_lon":"-97.4812",
+            "reason":"user_interaction_honk",
+            "camera":"0"
+        }
+        """;
+
+        // Act
+        var camEvent = CamEvent.Deserialize(json);
+
+        // Assert
+        camEvent.Should().NotBeNull();
+        camEvent.Timestamp.Should().Be(new DateTime(2023, 6, 3, 15, 54, 27));
+        camEvent.City.Should().Be("Taylor");
+        camEvent.EstLat.Should().Be(30.6075m);
+        camEvent.EstLon.Should().Be(-97.4812m);
+        camEvent.Reason.Should().Be("user_interaction_honk");
+        camEvent.Camera.Should().Be(0);
+    }
+
+    [Fact]
+    public static void Deserialization_OptionalProperties()
+    {
+        var json = """
+        {
+            "timestamp":"2023-06-03T15:54:27"
+        }
+        """;
+
+        var camEvent = CamEvent.Deserialize(json);
+
+        camEvent.Should().NotBeNull();
+        camEvent.Timestamp.Should().Be(new DateTime(2023, 6, 3, 15, 54, 27));
+        camEvent.City.Should().BeNull();
+        camEvent.EstLat.Should().Be(default);
+        camEvent.EstLon.Should().Be(default);
+        camEvent.Reason.Should().BeNull();
+        camEvent.Camera.Should().Be(default);
+    }
+
+    [Fact]
+    public static void Deserialization_TimestampRequired()
+    {
+        var json = """
+        {
+            "city":"Taylor",
+            "est_lat":"30.6075",
+            "est_lon":"-97.4812",
+            "reason":"user_interaction_honk",
+            "camera":"0"
+        }
+        """;
+
+        CamEvent.Deserialize(json).Should().BeNull();
+    }
+
+    [Fact]
+    public static void Deserialization_DoesNotThrowOnMalformedJson()
+    {
+        // Arrange
+        var json = """
+        {
+            "timestamp":"2023T15:54:27",
+            "city":"Taylor",
+            "est_lat":"lat",
+            "est_lon":"lon",
+            "reason":"user_interaction!",
+            "camera":"first"
+        }
+        """;
+
+        // Act
+        var camEvent = CamEvent.Deserialize(json);
+
+        // Assert
+        camEvent.Should().BeNull();
+    }
+}

TeslaCam.Tests/TeslaCam.Tests.csproj

@@ -1,6 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <ItemGroup>
+    <PackageReference Include="FluentAssertions" Version="7.0.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
     <PackageReference Include="xunit" Version="2.9.2" />
     <PackageReference Include="xunit.runner.visualstudio" Version="3.0.0" PrivateAssets="all">