Null check slash command localizations

src/Discord.Net.Core/Entities/Interactions/ApplicationCommandOption.cs

@@ -106,13 +106,17 @@ namespace Discord
             get => _nameLocalizations;
             set
             {
-                foreach (var (locale, name) in value)
+                if (value != null)
                 {
-                    if(!Regex.IsMatch(locale, @"^\w{2}(?:-\w{2})?$"))
-                        throw new ArgumentException($"Invalid locale: {locale}", nameof(locale));
+                    foreach (var (locale, name) in value)
+                    {
+                        if(!Regex.IsMatch(locale, @"^\w{2}(?:-\w{2})?$"))
+                            throw new ArgumentException($"Invalid locale: {locale}", nameof(locale));
 
-                    EnsureValidOptionName(name);
+                        EnsureValidOptionName(name);
+                    }
                 }
+
                 _nameLocalizations = value;
             }
         }
@@ -126,13 +130,17 @@ namespace Discord
             get => _descriptionLocalizations;
             set
             {
-                foreach (var (locale, description) in value)
+                if (value != null)
                 {
-                    if(!Regex.IsMatch(locale, @"^\w{2}(?:-\w{2})?$"))
-                        throw new ArgumentException($"Invalid locale: {locale}", nameof(locale));
+                    foreach (var (locale, description) in value)
+                    {
+                        if(!Regex.IsMatch(locale, @"^\w{2}(?:-\w{2})?$"))
+                            throw new ArgumentException($"Invalid locale: {locale}", nameof(locale));
 
-                    EnsureValidOptionDescription(description);
+                        EnsureValidOptionDescription(description);
+                    }
                 }
+
                 _descriptionLocalizations = value;
             }
         }

src/Discord.Net.Core/Entities/Interactions/ApplicationCommandOptionChoice.cs

@@ -55,18 +55,21 @@ namespace Discord
             get => _nameLocalizations;
             set
             {
-                foreach (var (locale, name) in value)
+                if (value != null)
                 {
-                    if (!Regex.IsMatch(locale, @"^\w{2}(?:-\w{2})?$"))
-                        throw new ArgumentException("Key values of the dictionary must be valid language codes.");
-
-                    switch (name.Length)
+                    foreach (var (locale, name) in value)
                     {
-                        case > 100:
-                            throw new ArgumentOutOfRangeException(nameof(value),
-                                "Name length must be less than or equal to 100.");
-                        case 0:
-                            throw new ArgumentOutOfRangeException(nameof(value), "Name length must at least 1.");
+                        if (!Regex.IsMatch(locale, @"^\w{2}(?:-\w{2})?$"))
+                            throw new ArgumentException("Key values of the dictionary must be valid language codes.");
+
+                        switch (name.Length)
+                        {
+                            case > 100:
+                                throw new ArgumentOutOfRangeException(nameof(value),
+                                    "Name length must be less than or equal to 100.");
+                            case 0:
+                                throw new ArgumentOutOfRangeException(nameof(value), "Name length must at least 1.");
+                        }
                     }
                 }
 

src/Discord.Net.Core/Entities/Interactions/ApplicationCommandProperties.cs

@@ -35,16 +35,20 @@ namespace Discord
             get => _nameLocalizations;
             set
             {
-                foreach (var (locale, name) in value)
+                if (value != null)
                 {
-                    if(!Regex.IsMatch(locale, @"^\w{2}(?:-\w{2})?$"))
-                        throw new ArgumentException($"Invalid locale: {locale}", nameof(locale));
+                    foreach (var (locale, name) in value)
+                    {
+                        if (!Regex.IsMatch(locale, @"^\w{2}(?:-\w{2})?$"))
+                            throw new ArgumentException($"Invalid locale: {locale}", nameof(locale));
 
-                    Preconditions.AtLeast(name.Length, 1, nameof(name));
-                    Preconditions.AtMost(name.Length, SlashCommandBuilder.MaxNameLength, nameof(name));
-                    if (!Regex.IsMatch(name, @"^[\w-]{1,32}$"))
-                        throw new ArgumentException("Option name cannot contain any special characters or whitespaces!", nameof(name));
+                        Preconditions.AtLeast(name.Length, 1, nameof(name));
+                        Preconditions.AtMost(name.Length, SlashCommandBuilder.MaxNameLength, nameof(name));
+                        if (!Regex.IsMatch(name, @"^[\w-]{1,32}$"))
+                            throw new ArgumentException("Option name cannot contain any special characters or whitespaces!", nameof(name));
+                    }
                 }
+
                 _nameLocalizations = value;
             }
         }
@@ -57,14 +61,18 @@ namespace Discord
             get => _descriptionLocalizations;
             set
             {
-                foreach (var (locale, description) in value)
+                if (value != null)
                 {
-                    if(!Regex.IsMatch(locale, @"^\w{2}(?:-\w{2})?$"))
-                        throw new ArgumentException($"Invalid locale: {locale}", nameof(locale));
+                    foreach (var (locale, description) in value)
+                    {
+                        if (!Regex.IsMatch(locale, @"^\w{2}(?:-\w{2})?$"))
+                            throw new ArgumentException($"Invalid locale: {locale}", nameof(locale));
 
-                    Preconditions.AtLeast(description.Length, 1, nameof(description));
-                    Preconditions.AtMost(description.Length, SlashCommandBuilder.MaxDescriptionLength, nameof(description));
+                        Preconditions.AtLeast(description.Length, 1, nameof(description));
+                        Preconditions.AtMost(description.Length, SlashCommandBuilder.MaxDescriptionLength, nameof(description));
+                    }
                 }
+
                 _descriptionLocalizations = value;
             }
         }

src/Discord.Net.Core/Entities/Interactions/SlashCommands/SlashCommandBuilder.cs

@@ -910,7 +910,7 @@ namespace Discord
             if (descriptionLocalizations is null)
                 throw new ArgumentNullException(nameof(descriptionLocalizations));
 
-            foreach (var (locale, description) in _descriptionLocalizations)
+            foreach (var (locale, description) in descriptionLocalizations)
             {
                 if(!Regex.IsMatch(locale, @"^\w{2}(?:-\w{2})?$"))
                     throw new ArgumentException($"Invalid locale: {locale}", nameof(locale));

test/Discord.Net.Tests.Unit/CommandBuilderTests.cs

@@ -0,0 +1,37 @@
+using System;
+using Discord;
+using Xunit;
+
+namespace Discord;
+
+public class CommandBuilderTests
+{
+    [Fact]
+    public void BuildSimpleSlashCommand()
+    {
+        var command = new SlashCommandBuilder()
+        .WithName("command")
+        .WithDescription("description")
+        .AddOption(
+            "option1",
+            ApplicationCommandOptionType.String,
+            "option1 description",
+            isRequired: true,
+            choices: new [] 
+            {
+                new ApplicationCommandOptionChoiceProperties()
+                {
+                    Name = "choice1", Value = "1"
+                }
+            })
+        .AddOptions(new SlashCommandOptionBuilder()
+            .WithName("option2")
+            .WithDescription("option2 description")
+            .WithType(ApplicationCommandOptionType.String)
+            .WithRequired(true)
+            .AddChannelType(ChannelType.Text)
+            .AddChoice("choice1", "1")
+            .AddChoice("choice2", "2"));
+        command.Build();
+    }
+}