fix: Support empty string enum serialization and deserialization (#8)

Author: HofmeisterAn

.github/workflows/ci.yml

@@ -8,15 +8,20 @@ on:
 jobs:
   build:
     runs-on: ubuntu-22.04
+    strategy:
+      matrix:
+        framework:
+          - net8.0
+          - net9.0
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
       - name: Setup .NET Core
         uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: 8.x
+          dotnet-version: 9.x
       - name: Build
-        run: dotnet build -c Release
+        run: dotnet build -c Release --framework ${{ matrix.framework }}
       - name: Test
-        run: dotnet test -c Release --no-build
+        run: dotnet test -c Release --framework ${{ matrix.framework }} --no-build

.github/workflows/publish.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Setup .NET Core
         uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: 8.x
+          dotnet-version: 9.x
       - name: Install NBGV tool
         run: dotnet tool install --tool-path . nbgv
       - name: Set Version

src/Directory.Build.props

@@ -4,7 +4,7 @@
 
     <PropertyGroup>
         <IsPackable>true</IsPackable>
-        <TargetFrameworks>net6.0;net8.0;netstandard2.0;netstandard2.1</TargetFrameworks>
+        <TargetFrameworks>net8.0;net9.0;netstandard2.0;netstandard2.1</TargetFrameworks>
         <PackageIconUrl>https://camo.githubusercontent.com/fa6d5c12609ed8a3ba1163b96f9e9979b8f59b0d/687474703a2f2f7765732e696f2f566663732f636f6e74656e74</PackageIconUrl>
         <Copyright>Copyright (c) .NET Foundation and Contributors</Copyright>
         <PackageTags>Docker Container C# .NET</PackageTags>

src/Docker.DotNet/Docker.DotNet.csproj

@@ -5,7 +5,10 @@
     <AssemblyName>Docker.DotNet</AssemblyName>
     <LangVersion>latest</LangVersion>
   </PropertyGroup>
-  <ItemGroup>
+  <ItemGroup Condition="$(TargetFramework) == 'net8.0'">
+    <PackageReference Include="System.IO.Pipelines" Version="8.0.0" />
+  </ItemGroup>
+  <ItemGroup Condition="$(TargetFrameworkIdentifier) == '.NETStandard'">
     <PackageReference Include="System.Buffers" Version="4.5.1" />
     <PackageReference Include="System.IO.Pipelines" Version="8.0.0" />
     <PackageReference Include="System.Net.Http.Json" Version="8.0.1" />

src/Docker.DotNet/JsonEnumMemberConverter.cs

@@ -8,27 +8,41 @@
 using System.Text.Json;
 using System.Text.Json.Serialization;
 
-// https://github.com/dotnet/runtime/issues/74385#issuecomment-1705083109.
-internal sealed class JsonEnumMemberConverter<TEnum> : JsonStringEnumConverter<TEnum> where TEnum : struct, Enum
+internal sealed class JsonEnumMemberConverter<TEnum> : JsonConverter<TEnum> where TEnum : struct, Enum
 {
-    public JsonEnumMemberConverter() : base(ResolveNamingPolicy())
-    {
-    }
+    private readonly Dictionary<string, string> _enumFields = typeof(TEnum).GetFields(BindingFlags.Public | BindingFlags.Static)
+        .Select(field => (Name: field.Name, Attribute: field.GetCustomAttribute<EnumMemberAttribute>()))
+        .Where(item => item.Attribute != null && item.Attribute.Value != null)
+        .ToDictionary(item => item.Name, item => item.Attribute.Value);
 
-    private static JsonNamingPolicy ResolveNamingPolicy()
+    public override TEnum Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
     {
-        return new EnumMemberNamingPolicy(typeof(TEnum).GetFields(BindingFlags.Public | BindingFlags.Static)
-            .Select(fieldInfo => new KeyValuePair<string, string>(fieldInfo.Name, fieldInfo.GetCustomAttribute<EnumMemberAttribute>()?.Value))
-            .Where(kvp => kvp.Value != null)
-            .ToDictionary(kvp => kvp.Key, kvp => kvp.Value));
+        var stringValue = reader.GetString();
+
+        var enumField = _enumFields.SingleOrDefault(item => item.Value.Equals(stringValue, StringComparison.Ordinal));
+
+        if (enumField.Key == null)
+        {
+            throw new JsonException($"Unknown enum value '{stringValue}' for enum type '{typeof(TEnum).Name}'.");
+        }
+
+        if (!Enum.TryParse(enumField.Key, out TEnum enumValue))
+        {
+            throw new JsonException($"Unable to convert '{stringValue}' to a valid enum value of type '{typeof(TEnum).Name}'.");
+        }
+
+        return enumValue;
     }
 
-    private sealed class EnumMemberNamingPolicy : JsonNamingPolicy
+    public override void Write(Utf8JsonWriter writer, TEnum value, JsonSerializerOptions options)
     {
-        private readonly IReadOnlyDictionary<string, string> _map;
+        var enumName = value.ToString();
 
-        public EnumMemberNamingPolicy(IReadOnlyDictionary<string, string> map) => _map = map;
+        if (!_enumFields.TryGetValue(enumName, out var stringValue))
+        {
+            throw new JsonException($"Unable to convert '{enumName}' to a valid enum value of type '{nameof(String)}'.");
+        }
 
-        public override string ConvertName(string name) => _map.TryGetValue(name, out var newName) ? newName : name;
+        writer.WriteStringValue(stringValue);
     }
 }

src/Docker.DotNet/JsonSerializer.cs

@@ -18,8 +18,8 @@ internal sealed class JsonSerializer
 
     private JsonSerializer()
     {
-        _options.Converters.Add(new JsonEnumMemberConverter<TaskState>());
         _options.Converters.Add(new JsonEnumMemberConverter<RestartPolicyKind>());
+        _options.Converters.Add(new JsonEnumMemberConverter<TaskState>());
         _options.Converters.Add(new JsonDateTimeConverter());
         _options.Converters.Add(new JsonNullableDateTimeConverter());
         _options.Converters.Add(new JsonBase64Converter());

test/Docker.DotNet.Tests/Docker.DotNet.Tests.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>net8.0</TargetFramework>
+    <TargetFrameworks>net8.0;net9.0</TargetFrameworks>
     <IsPackable>false</IsPackable>
     <IsPublishable>false</IsPublishable>
   </PropertyGroup>

test/Docker.DotNet.Tests/ISystemOperations.Tests.cs

@@ -118,7 +118,7 @@ await _dockerClient.Images.DeleteImageAsync(
 
             await cts.CancelAsync();
 
-            await Assert.ThrowsAsync<OperationCanceledException>(() => task).ConfigureAwait(false);
+            await Assert.ThrowsAsync<OperationCanceledException>(() => task);
 
             Assert.True(wasProgressCalled);
         }

test/Docker.DotNet.Tests/JsonEnumMemberConverterTest.cs

@@ -0,0 +1,44 @@
+namespace Docker.DotNet.Tests;
+
+using System.Text;
+using Docker.DotNet.Models;
+using Xunit;
+
+public sealed class JsonEnumMemberConverterTests
+{
+    [Theory]
+    [ClassData(typeof(RestartPolicyKindTestData))]
+    public void JsonSerialization_ShouldSerializeAndDeserializeCorrectly(RestartPolicyKind restartPolicyKind)
+    {
+        // Given
+        var parameters = new CreateContainerParameters
+        {
+            HostConfig = new HostConfig
+            {
+                RestartPolicy = new RestartPolicy
+                {
+                    Name = restartPolicyKind
+                }
+            }
+        };
+
+        // When
+        var jsonString = JsonSerializer.Instance.Serialize(parameters);
+        var deserializedParameters = JsonSerializer.Instance.Deserialize<CreateContainerParameters>(Encoding.UTF8.GetBytes(jsonString));
+
+        // Then
+        Assert.Equal(restartPolicyKind, deserializedParameters.HostConfig.RestartPolicy.Name);
+    }
+
+    private sealed class RestartPolicyKindTestData : TheoryData<RestartPolicyKind>
+    {
+        public RestartPolicyKindTestData()
+        {
+            Add(RestartPolicyKind.Undefined);
+            Add(RestartPolicyKind.No);
+            Add(RestartPolicyKind.Always);
+            Add(RestartPolicyKind.OnFailure);
+            Add(RestartPolicyKind.UnlessStopped);
+        }
+    }
+}

version.json

@@ -1,6 +1,6 @@
 {
   "$schema": "https://raw.githubusercontent.com/dotnet/Nerdbank.GitVersioning/master/src/NerdBank.GitVersioning/version.schema.json",
-  "version": "3.126.0",
+  "version": "3.126.1",
   "nugetPackageVersion": {
     "semVer": 2
   },