Merge LuaTable.GetValueOrDefault and allow nullable TValue

Author: Quahu

src/Laylua.Tests/Tests/Library/Entities/Table/LuaTableTests.cs

@@ -116,6 +116,34 @@ public void SetAndGetValue_StringInt_ReturnsValidValue()
         Assert.That(value, Is.EqualTo(1));
     }
 
+    [Test]
+    public void GetValueOrDefault_MissingNullableInt_ReturnsNull()
+    {
+        // Arrange
+        using var table = Lua.CreateTable();
+
+        // Act
+        table.SetValue("MissingValue", (int?) null);
+        var missingValue = table.GetValueOrDefault<string, int?>("MissingValue");
+
+        // Assert
+        Assert.That(missingValue, Is.Null);
+    }
+
+    [Test]
+    public void GetValueOrDefault_MissingNullableInt_DefaultValue_ReturnsDefaultValue()
+    {
+        // Arrange
+        using var table = Lua.CreateTable();
+
+        // Act
+        table.SetValue("MissingValue", (int?) null);
+        var missingValue = table.GetValueOrDefault<string, int?>("MissingValue", 42);
+
+        // Assert
+        Assert.That(missingValue, Is.EqualTo(42));
+    }
+
     [Test]
     public void Count_ReturnsValidCount()
     {

src/Laylua/Library/Entities/Reference/Table/LuaTable.cs

@@ -348,24 +348,6 @@ public TValue GetValue<TKey, TValue>(TKey key)
         }
     }
 
-    /// <inheritdoc cref="LuaReference._reference"/>
-    /// <summary>
-    ///     Gets a value with the given key in the table.
-    /// </summary>
-    /// <param name="key"> The key of the value to get. </param>
-    /// <typeparam name="TKey"> The type of the key. </typeparam>
-    /// <typeparam name="TValue"> The type of the value. </typeparam>
-    /// <returns>
-    ///     The value from the table or <see langword="default"/>.
-    /// </returns>
-    [MethodImpl(MethodImplOptions.NoInlining)]
-    public TValue? GetValueOrDefault<TKey, TValue>(TKey key)
-        where TKey : notnull
-        where TValue : notnull
-    {
-        return TryGetValue<TKey, TValue>(key, out var value) ? value : default;
-    }
-
     /// <inheritdoc cref="LuaReference._reference"/>
     /// <summary>
     ///     Gets a value with the given key in the table.
@@ -378,11 +360,12 @@ public TValue GetValue<TKey, TValue>(TKey key)
     ///     The value from the table or <paramref name="defaultValue"/>.
     /// </returns>
     [MethodImpl(MethodImplOptions.NoInlining)]
-    public TValue? GetValueOrDefault<TKey, TValue>(TKey key, TValue defaultValue)
+    public TValue? GetValueOrDefault<TKey, TValue>(TKey key, TValue? defaultValue = default)
         where TKey : notnull
-        where TValue : notnull
     {
+#pragma warning disable CS8714 // The type cannot be used as type parameter in the generic type or method. Nullability of type argument doesn't match 'notnull' constraint.
         return TryGetValue<TKey, TValue>(key, out var value) ? value : defaultValue;
+#pragma warning restore CS8714 // The type cannot be used as type parameter in the generic type or method. Nullability of type argument doesn't match 'notnull' constraint.
     }
 
     /// <summary>