feat: add StringEnum<TEnum> (#98)

src/Octokit.Webhooks/Converter/StringEnumConverter.cs

@@ -0,0 +1,18 @@
+namespace Octokit.Webhooks.Converter;
+
+using System;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Octokit.Webhooks.Extensions;
+
+public sealed class StringEnumConverter<TEnum> : JsonConverter<StringEnum<TEnum>>
+    where TEnum : struct
+{
+    public override StringEnum<TEnum> Read(
+        ref Utf8JsonReader reader,
+        Type typeToConvert,
+        JsonSerializerOptions options) => new(reader.GetString()!);
+
+    public override void Write(Utf8JsonWriter writer, StringEnum<TEnum> value, JsonSerializerOptions options) =>
+        JsonSerializer.Serialize(writer, value.StringValue, options);
+}

src/Octokit.Webhooks/Converter/StringEnumEnumerableConverter.cs

@@ -0,0 +1,61 @@
+namespace Octokit.Webhooks.Converter;
+
+using System;
+using System.Collections.Generic;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Octokit.Webhooks.Extensions;
+
+public sealed class StringEnumEnumerableConverter<TEnum> : JsonConverter<IEnumerable<StringEnum<TEnum>>>
+    where TEnum : struct
+{
+    private static readonly JsonSerializerOptions Options = new()
+    {
+        Converters = { Activator.CreateInstance<StringEnumConverter<TEnum>>() },
+    };
+
+    public override IEnumerable<StringEnum<TEnum>> Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) =>
+        ReadInternal(ref reader);
+
+    public override void Write(Utf8JsonWriter writer, IEnumerable<StringEnum<TEnum>> value, JsonSerializerOptions options) =>
+        WriteInternal(writer, value);
+
+    private static List<StringEnum<TEnum>> ReadInternal(ref Utf8JsonReader reader)
+    {
+        if (reader.TokenType == JsonTokenType.Null)
+        {
+            throw new JsonException("Unexpected null value.");
+        }
+
+        var returnValue = new List<StringEnum<TEnum>>();
+
+        while (reader.TokenType != JsonTokenType.EndArray)
+        {
+            if (reader.TokenType != JsonTokenType.StartArray)
+            {
+                returnValue.Add((StringEnum<TEnum>)JsonSerializer.Deserialize(ref reader, typeof(StringEnum<TEnum>), Options)!);
+            }
+
+            reader.Read();
+        }
+
+        return returnValue!;
+    }
+
+    private static void WriteInternal(Utf8JsonWriter writer, IEnumerable<StringEnum<TEnum>> value)
+    {
+        if (value == null)
+        {
+            throw new JsonException("Unexpected null value.");
+        }
+
+        writer.WriteStartArray();
+
+        foreach (var data in value)
+        {
+            JsonSerializer.Serialize(writer, data, Options);
+        }
+
+        writer.WriteEndArray();
+    }
+}

src/Octokit.Webhooks/Events/CreateEvent.cs

@@ -8,7 +8,8 @@ public sealed record CreateEvent : WebhookEvent
     public string Ref { get; init; } = null!;
 
     [JsonPropertyName("ref_type")]
-    public RefType RefType { get; init; }
+    [JsonConverter(typeof(StringEnumConverter<RefType>))]
+    public StringEnum<RefType> RefType { get; init; } = null!;
 
     [JsonPropertyName("master_branch")]
     public string MasterBranch { get; init; } = null!;

src/Octokit.Webhooks/Events/DeleteEvent.cs

@@ -8,7 +8,8 @@ public sealed record DeleteEvent : WebhookEvent
     public string Ref { get; init; } = null!;
 
     [JsonPropertyName("ref_type")]
-    public RefType RefType { get; init; }
+    [JsonConverter(typeof(StringEnumConverter<RefType>))]
+    public StringEnum<RefType> RefType { get; init; } = null!;
 
     [JsonPropertyName("pusher_type")]
     public string PusherType { get; init; } = null!;

src/Octokit.Webhooks/Events/InstallationRepositoriesEvent.cs

@@ -9,7 +9,8 @@ public abstract record InstallationRepositoriesEvent : WebhookEvent
     public new Models.Installation Installation { get; init; } = null!;
 
     [JsonPropertyName("repository_selection")]
-    public InstallationRepositorySelection RepositorySelection { get; init; }
+    [JsonConverter(typeof(StringEnumConverter<InstallationRepositorySelection>))]
+    public StringEnum<InstallationRepositorySelection> RepositorySelection { get; init; } = null!;
 
     [JsonPropertyName("repositories_added")]
     public IEnumerable<Models.InstallationRepositoriesEvent.Repository> RepositoriesAdded { get; init; } = null!;

src/Octokit.Webhooks/Events/InstallationTarget/InstallationTargetRenamedEvent.cs

@@ -16,5 +16,6 @@ public sealed record InstallationTargetRenamedEvent : InstallationTargetEvent
     public Changes Changes { get; init; } = null!;
 
     [JsonPropertyName("target_type")]
-    public InstallationTargetType TargetType { get; init; }
+    [JsonConverter(typeof(StringEnumConverter<InstallationTargetType>))]
+    public StringEnum<InstallationTargetType> TargetType { get; init; } = null!;
 }

src/Octokit.Webhooks/Events/MembershipEvent.cs

@@ -8,7 +8,8 @@
 public abstract record MembershipEvent : WebhookEvent
 {
     [JsonPropertyName("scope")]
-    public Scope Scope { get; init; }
+    [JsonConverter(typeof(StringEnumConverter<Scope>))]
+    public StringEnum<Scope> Scope { get; init; } = null!;
 
     [JsonPropertyName("member")]
     public User Member { get; init; } = null!;

src/Octokit.Webhooks/Events/RepositoryImportEvent.cs

@@ -7,5 +7,6 @@
 public sealed record RepositoryImportEvent : WebhookEvent
 {
     [JsonPropertyName("status")]
-    public Status Status { get; init; }
+    [JsonConverter(typeof(StringEnumConverter<Status>))]
+    public StringEnum<Status> Status { get; init; } = null!;
 }

src/Octokit.Webhooks/Events/StatusEvent.cs

@@ -28,7 +28,8 @@ public sealed record StatusEvent : WebhookEvent
     public string? Description { get; init; }
 
     [JsonPropertyName("state")]
-    public StatusState State { get; init; }
+    [JsonConverter(typeof(StringEnumConverter<StatusState>))]
+    public StringEnum<StatusState> State { get; init; } = null!;
 
     [JsonPropertyName("commit")]
     public Commit Commit { get; init; } = null!;

src/Octokit.Webhooks/Extensions/StringEnum.cs

@@ -0,0 +1,104 @@
+namespace Octokit.Webhooks.Extensions;
+
+using System;
+using System.Globalization;
+using System.Linq;
+using System.Runtime.Serialization;
+using JetBrains.Annotations;
+
+[PublicAPI]
+public sealed record StringEnum<TEnum>
+    where TEnum : struct
+{
+    private TEnum? parsedValue;
+
+    public StringEnum(string stringValue)
+    {
+        this.StringValue = stringValue;
+        this.parsedValue = null;
+    }
+
+    public StringEnum(TEnum parsedValue)
+    {
+        if (!Enum.IsDefined(typeof(TEnum), parsedValue))
+        {
+            throw GetArgumentException(parsedValue.ToString());
+        }
+
+        this.StringValue = ToEnumString(parsedValue);
+        this.parsedValue = parsedValue;
+    }
+
+    public string StringValue { get; }
+
+    public TEnum Value => this.parsedValue ??= this.ParseValue();
+
+    public static implicit operator StringEnum<TEnum>(string value) => new(value);
+
+    public static implicit operator StringEnum<TEnum>(TEnum parsedValue) => new(parsedValue);
+
+    public bool TryParse(out TEnum value)
+    {
+        if (this.parsedValue is not null)
+        {
+            value = this.parsedValue.Value;
+            return true;
+        }
+
+        try
+        {
+            value = ToEnum(this.StringValue);
+            this.parsedValue = value;
+            return true;
+        }
+        catch (ArgumentException)
+        {
+            value = default;
+            return false;
+        }
+    }
+
+    private static ArgumentException GetArgumentException(string? value) => new(string.Format(
+        CultureInfo.InvariantCulture,
+        "Value '{0}' is not a valid '{1}' enum value.",
+        value,
+        typeof(TEnum).Name));
+
+    private TEnum ParseValue()
+    {
+        if (this.TryParse(out var value))
+        {
+            return value;
+        }
+
+        throw GetArgumentException(this.StringValue);
+    }
+
+    private static string ToEnumString(TEnum type)
+    {
+        var enumType = typeof(TEnum);
+        var name = Enum.GetName(enumType, type);
+        if (name is not null)
+        {
+            var enumMemberAttribute = ((EnumMemberAttribute[])enumType.GetField(name)!.GetCustomAttributes(typeof(EnumMemberAttribute), true)).Single();
+            return enumMemberAttribute.Value!;
+        }
+
+        throw new ArgumentException(type.ToString());
+    }
+
+    private static TEnum ToEnum(string str)
+    {
+        var enumType = typeof(TEnum);
+        foreach (var name in Enum.GetNames(enumType))
+        {
+            var enumMemberAttribute = ((EnumMemberAttribute[])enumType.GetField(name)!.GetCustomAttributes(typeof(EnumMemberAttribute), true)).Single();
+            if (enumMemberAttribute.Value == str)
+            {
+                return (TEnum)Enum.Parse(enumType, name);
+            }
+        }
+
+        throw new ArgumentException(str);
+    }
+}

src/Octokit.Webhooks/Models/ActiveLockReason.cs

@@ -1,10 +1,8 @@
 namespace Octokit.Webhooks.Models;
 
 [PublicAPI]
-[JsonConverter(typeof(JsonStringEnumMemberConverterWithFallback))]
 public enum ActiveLockReason
 {
-    Unknown = -1,
     [EnumMember(Value = "resolved")]
     Resolved,
     [EnumMember(Value = "off-topic")]

src/Octokit.Webhooks/Models/App.cs

@@ -39,5 +39,6 @@ public sealed record App
     public AppPermissions? Permissions { get; init; }
 
     [JsonPropertyName("events")]
-    public IEnumerable<AppEvent>? Events { get; init; }
+    [JsonConverter(typeof(StringEnumEnumerableConverter<AppEvent>))]
+    public IEnumerable<StringEnum<AppEvent>>? Events { get; init; }
 }

src/Octokit.Webhooks/Models/AppEvent.cs

@@ -1,10 +1,8 @@
 namespace Octokit.Webhooks.Models;
 
 [PublicAPI]
-[JsonConverter(typeof(JsonStringEnumMemberConverterWithFallback))]
 public enum AppEvent
 {
-    Unknown = -1,
     [EnumMember(Value = "*")]
     All,
     [EnumMember(Value = "branch_protection_rule")]