baseline: OpenMU upstream b5a0961 (fresh source)

src/PlugIns/TypeExtensions.cs

@@ -0,0 +1,54 @@
+// <copyright file="TypeExtensions.cs" company="MUnique">
+// Licensed under the MIT License. See LICENSE file in the project root for full license information.
+// </copyright>
+
+namespace MUnique.OpenMU.PlugIns;
+
+/// <summary>
+/// Extension methods for <see cref="Type"/>.
+/// </summary>
+public static class TypeExtensions
+{
+    /// <summary>
+    /// Gets the implemented interface of <see cref="ISupportCustomConfiguration{T}"/>.
+    /// </summary>
+    /// <param name="plugInType">Type of the plug in.</param>
+    /// <returns>The implemented interface of <see cref="ISupportCustomConfiguration{T}"/>.</returns>
+    public static Type? GetCustomConfigurationSupportInterfaceType(this Type plugInType)
+    {
+        return plugInType.GetInterfaces()
+            .Where(i => i.IsGenericType)
+            .FirstOrDefault(i => i.GetGenericTypeDefinition() == typeof(ISupportCustomConfiguration<>));
+    }
+
+    /// <summary>
+    /// Gets the generic type parameter of <see cref="ISupportCustomConfiguration{T}"/>.
+    /// </summary>
+    /// <param name="plugInType">Type of the plug in.</param>
+    /// <returns>The generic type parameter of <see cref="ISupportCustomConfiguration{T}"/>.</returns>
+    public static Type? GetCustomConfigurationType(this Type plugInType)
+    {
+        if (plugInType.GetCustomConfigurationSupportInterfaceType() is { } configSupportInterface)
+        {
+            return configSupportInterface.GenericTypeArguments[0];
+        }
+
+        return null;
+    }
+
+    /// <summary>
+    /// Determines whether this type is a <see cref="Nullable{T}"/>.
+    /// </summary>
+    /// <param name="type">The type.</param>
+    /// <returns>
+    ///   <c>true</c> if the specified type is a nullable; otherwise, <c>false</c>.
+    /// </returns>
+    public static bool IsNullable(this Type type) => type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>);
+
+    /// <summary>
+    /// Gets the generic type argument of the nullable.
+    /// </summary>
+    /// <param name="type">The nullable type.</param>
+    /// <returns>The generic type argument of the nullable.</returns>
+    public static Type GetTypeOfNullable(this Type type) => type.IsNullable() ? type.GetGenericArguments().First() : type;
+}