Add various property validation in EmbedBuilder (#711)

* Add various property validation in EmbedBuilder

* Embed URI changes

Changes property types for any URLs in Embeds to System.URI.
Adding field name/value null/empty checks.

* including property names in argumentexceptions

* Adds overall embed length check

src/Discord.Net.Core/Entities/Messages/Embed.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Immutable;
 using System.Diagnostics;
+using System.Linq;
 
 namespace Discord
 {
@@ -10,7 +11,7 @@ namespace Discord
         public string Type { get; }
 
         public string Description { get; internal set; }
-        public string Url { get; internal set; }
+        public Uri Url { get; internal set; }
         public string Title { get; internal set; }
         public DateTimeOffset? Timestamp { get; internal set; }
         public Color? Color { get; internal set; }
@@ -30,7 +31,7 @@ namespace Discord
         internal Embed(string type, 
             string title,
             string description,
-            string url,
+            Uri url,
             DateTimeOffset? timestamp,
             Color? color,
             EmbedImage? image,
@@ -56,6 +57,8 @@ namespace Discord
             Fields = fields;
         }
 
+        public int Length => Title?.Length + Author?.Name?.Length + Description?.Length + Footer?.Text?.Length + Fields.Sum(f => f.Name.Length + f.Value.ToString().Length) ?? 0;
+
         public override string ToString() => Title;
         private string DebuggerDisplay => $"{Title} ({Type})";
     }

src/Discord.Net.Core/Entities/Messages/EmbedAuthor.cs

@@ -1,4 +1,5 @@
-using System.Diagnostics;
+using System;
+using System.Diagnostics;
 
 namespace Discord
 {
@@ -6,11 +7,11 @@ namespace Discord
     public struct EmbedAuthor
     {
         public string Name { get; internal set; }
-        public string Url { get; internal set; }
-        public string IconUrl { get; internal set; }
-        public string ProxyIconUrl { get; internal set; }
+        public Uri Url { get; internal set; }
+        public Uri IconUrl { get; internal set; }
+        public Uri ProxyIconUrl { get; internal set; }
 
-        internal EmbedAuthor(string name, string url, string iconUrl, string proxyIconUrl)
+        internal EmbedAuthor(string name, Uri url, Uri iconUrl, Uri proxyIconUrl)
         {
             Name = name;
             Url = url;

src/Discord.Net.Core/Entities/Messages/EmbedFooter.cs

@@ -1,4 +1,5 @@
-using System.Diagnostics;
+using System;
+using System.Diagnostics;
 
 namespace Discord
 {
@@ -6,10 +7,10 @@ namespace Discord
     public struct EmbedFooter
     {
         public string Text { get; internal set; }
-        public string IconUrl { get; internal set; }
-        public string ProxyUrl { get; internal set; }
+        public Uri IconUrl { get; internal set; }
+        public Uri ProxyUrl { get; internal set; }
 
-        internal EmbedFooter(string text, string iconUrl, string proxyUrl)
+        internal EmbedFooter(string text, Uri iconUrl, Uri proxyUrl)
         {
             Text = text;
             IconUrl = iconUrl;

src/Discord.Net.Core/Entities/Messages/EmbedImage.cs

@@ -1,16 +1,17 @@
-using System.Diagnostics;
+using System;
+using System.Diagnostics;
 
 namespace Discord
 {
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
     public struct EmbedImage
     {
-        public string Url { get; }
-        public string ProxyUrl { get; }
+        public Uri Url { get; }
+        public Uri ProxyUrl { get; }
         public int? Height { get; }
         public int? Width { get; }
 
-        internal EmbedImage(string url, string proxyUrl, int? height, int? width)
+        internal EmbedImage(Uri url, Uri proxyUrl, int? height, int? width)
         {
             Url = url;
             ProxyUrl = proxyUrl;
@@ -19,6 +20,6 @@ namespace Discord
         }
 
         private string DebuggerDisplay => $"{Url} ({(Width != null && Height != null ? $"{Width}x{Height}" : "0x0")})";
-        public override string ToString() => Url;
+        public override string ToString() => Url.ToString();
     }
 }

src/Discord.Net.Core/Entities/Messages/EmbedProvider.cs

@@ -1,4 +1,5 @@
-using System.Diagnostics;
+using System;
+using System.Diagnostics;
 
 namespace Discord
 {
@@ -6,9 +7,9 @@ namespace Discord
     public struct EmbedProvider
     {
         public string Name { get; }
-        public string Url { get; }
+        public Uri Url { get; }
 
-        internal EmbedProvider(string name, string url)
+        internal EmbedProvider(string name, Uri url)
         {
             Name = name;
             Url = url;

src/Discord.Net.Core/Entities/Messages/EmbedThumbnail.cs

@@ -1,16 +1,17 @@
-using System.Diagnostics;
+using System;
+using System.Diagnostics;
 
 namespace Discord
 {
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
     public struct EmbedThumbnail
     {
-        public string Url { get; }
-        public string ProxyUrl { get; }
+        public Uri Url { get; }
+        public Uri ProxyUrl { get; }
         public int? Height { get; }
         public int? Width { get; }
 
-        internal EmbedThumbnail(string url, string proxyUrl, int? height, int? width)
+        internal EmbedThumbnail(Uri url, Uri proxyUrl, int? height, int? width)
         {
             Url = url;
             ProxyUrl = proxyUrl;
@@ -19,6 +20,6 @@ namespace Discord
         }
 
         private string DebuggerDisplay => $"{Url} ({(Width != null && Height != null ? $"{Width}x{Height}" : "0x0")})";
-        public override string ToString() => Url;
+        public override string ToString() => Url.ToString();
     }
 }

src/Discord.Net.Core/Entities/Messages/EmbedVideo.cs

@@ -1,15 +1,16 @@
-using System.Diagnostics;
+using System;
+using System.Diagnostics;
 
 namespace Discord
 {
     [DebuggerDisplay("{DebuggerDisplay,nq}")]
     public struct EmbedVideo
     {
-        public string Url { get; }
+        public Uri Url { get; }
         public int? Height { get; }
         public int? Width { get; }
 
-        internal EmbedVideo(string url, int? height, int? width)
+        internal EmbedVideo(Uri url, int? height, int? width)
         {
             Url = url;
             Height = height;
@@ -17,6 +18,6 @@ namespace Discord
         }
 
         private string DebuggerDisplay => $"{Url} ({(Width != null && Height != null ? $"{Width}x{Height}" : "0x0")})";
-        public override string ToString() => Url;
+        public override string ToString() => Url.ToString();
     }
 }

src/Discord.Net.Core/Entities/Messages/IEmbed.cs

@@ -5,7 +5,7 @@ namespace Discord
 {
     public interface IEmbed
     {
-        string Url { get; }
+        Uri Url { get; }
         string Type { get; }
         string Title { get; }
         string Description { get; }

src/Discord.Net.Rest/API/Common/Embed.cs

@@ -13,7 +13,7 @@ namespace Discord.API
         [JsonProperty("description")]
         public string Description { get; set; }
         [JsonProperty("url")]
-        public string Url { get; set; }
+        public Uri Url { get; set; }
         [JsonProperty("color")]
         public uint? Color { get; set; }
         [JsonProperty("timestamp")]

src/Discord.Net.Rest/API/Common/EmbedAuthor.cs

@@ -1,4 +1,5 @@
-using Newtonsoft.Json;
+using System;
+using Newtonsoft.Json;
 
 namespace Discord.API
 {
@@ -7,10 +8,10 @@ namespace Discord.API
         [JsonProperty("name")]
         public string Name { get; set; }
         [JsonProperty("url")]
-        public string Url { get; set; }
+        public Uri Url { get; set; }
         [JsonProperty("icon_url")]
-        public string IconUrl { get; set; }
+        public Uri IconUrl { get; set; }
         [JsonProperty("proxy_icon_url")]
-        public string ProxyIconUrl { get; set; }
+        public Uri ProxyIconUrl { get; set; }
     }
 }

src/Discord.Net.Rest/API/Common/EmbedFooter.cs

@@ -1,4 +1,5 @@
-using Newtonsoft.Json;
+using System;
+using Newtonsoft.Json;
 
 namespace Discord.API
 {
@@ -7,8 +8,8 @@ namespace Discord.API
         [JsonProperty("text")]
         public string Text { get; set; }
         [JsonProperty("icon_url")]
-        public string IconUrl { get; set; }
+        public Uri IconUrl { get; set; }
         [JsonProperty("proxy_icon_url")]
-        public string ProxyIconUrl { get; set; }
+        public Uri ProxyIconUrl { get; set; }
     }
 }

src/Discord.Net.Rest/API/Common/EmbedImage.cs

@@ -1,4 +1,5 @@
 #pragma warning disable CS1591
+using System;
 using Newtonsoft.Json;
 
 namespace Discord.API
@@ -6,9 +7,9 @@ namespace Discord.API
     internal class EmbedImage
     {
         [JsonProperty("url")]
-        public string Url { get; set; }
+        public Uri Url { get; set; }
         [JsonProperty("proxy_url")]
-        public string ProxyUrl { get; set; }
+        public Uri ProxyUrl { get; set; }
         [JsonProperty("height")]
         public Optional<int> Height { get; set; }
         [JsonProperty("width")]

src/Discord.Net.Rest/API/Common/EmbedProvider.cs

@@ -1,4 +1,5 @@
 #pragma warning disable CS1591
+using System;
 using Newtonsoft.Json;
 
 namespace Discord.API
@@ -8,6 +9,6 @@ namespace Discord.API
         [JsonProperty("name")]
         public string Name { get; set; }
         [JsonProperty("url")]
-        public string Url { get; set; }
+        public Uri Url { get; set; }
     }
 }

src/Discord.Net.Rest/API/Common/EmbedThumbnail.cs

@@ -1,4 +1,5 @@
 #pragma warning disable CS1591
+using System;
 using Newtonsoft.Json;
 
 namespace Discord.API
@@ -6,9 +7,9 @@ namespace Discord.API
     internal class EmbedThumbnail
     {
         [JsonProperty("url")]
-        public string Url { get; set; }
+        public Uri Url { get; set; }
         [JsonProperty("proxy_url")]
-        public string ProxyUrl { get; set; }
+        public Uri ProxyUrl { get; set; }
         [JsonProperty("height")]
         public Optional<int> Height { get; set; }
         [JsonProperty("width")]

src/Discord.Net.Rest/API/Common/EmbedVideo.cs

@@ -1,4 +1,5 @@
 #pragma warning disable CS1591
+using System;
 using Newtonsoft.Json;
 
 namespace Discord.API
@@ -6,7 +7,7 @@ namespace Discord.API
     internal class EmbedVideo
     {
         [JsonProperty("url")]
-        public string Url { get; set; }
+        public Uri Url { get; set; }
         [JsonProperty("height")]
         public Optional<int> Height { get; set; }
         [JsonProperty("width")]

src/Discord.Net.Rest/Entities/Messages/EmbedBuilder.cs

@@ -8,19 +8,42 @@ namespace Discord
     {
         private readonly Embed _embed;
 
+        public const int MaxFieldCount = 25;
+        public const int MaxTitleLength = 256;
+        public const int MaxDescriptionLength = 2048;
+        public const int MaxEmbedLength = 6000; // user bot limit is 2000, but we don't validate that here.
+
         public EmbedBuilder()
         {
             _embed = new Embed("rich");
             Fields = new List<EmbedFieldBuilder>();
         }
 
-        public string Title { get { return _embed.Title; } set { _embed.Title = value; } }
-        public string Description { get { return _embed.Description; } set { _embed.Description = value; } }
-        public string Url { get { return _embed.Url; } set { _embed.Url = value; } }
-        public string ThumbnailUrl { get { return _embed.Thumbnail?.Url; } set { _embed.Thumbnail = new EmbedThumbnail(value, null, null, null); } }
-        public string ImageUrl { get { return _embed.Image?.Url; } set { _embed.Image = new EmbedImage(value, null, null, null); } }
-        public DateTimeOffset? Timestamp { get { return _embed.Timestamp; } set { _embed.Timestamp = value; } }
-        public Color? Color { get { return _embed.Color; } set { _embed.Color = value; } }
+        public string Title
+        {
+            get => _embed.Title;
+            set
+            {
+                if (value?.Length > MaxTitleLength) throw new ArgumentException($"Title length must be less than or equal to {MaxTitleLength}.", nameof(Title));
+                _embed.Title = value;
+            }
+        }
+
+        public string Description
+        {
+            get => _embed.Description;
+            set
+            {
+                if (value?.Length > MaxDescriptionLength) throw new ArgumentException($"Description length must be less than or equal to {MaxDescriptionLength}.", nameof(Description));
+                _embed.Description = value;
+            }
+        }
+
+        public Uri Url { get => _embed.Url; set { _embed.Url = value; } }
+        public Uri ThumbnailUrl { get => _embed.Thumbnail?.Url; set { _embed.Thumbnail = new EmbedThumbnail(value, null, null, null); } }
+        public Uri ImageUrl { get => _embed.Image?.Url; set { _embed.Image = new EmbedImage(value, null, null, null); } }
+        public DateTimeOffset? Timestamp { get => _embed.Timestamp; set { _embed.Timestamp = value; } }
+        public Color? Color { get => _embed.Color; set { _embed.Color = value; } }
 
         public EmbedAuthorBuilder Author { get; set; }
         public EmbedFooterBuilder Footer { get; set; }
@@ -30,8 +53,10 @@ namespace Discord
             get => _fields;
             set
             {
-                if (value != null) _fields = value;
-                else throw new ArgumentNullException("Cannot set an embed builder's fields collection to null", nameof(value));
+
+                if (value == null) throw new ArgumentNullException("Cannot set an embed builder's fields collection to null", nameof(Fields));
+                if (value.Count > MaxFieldCount) throw new ArgumentException($"Field count must be less than or equal to {MaxFieldCount}.", nameof(Fields));
+                _fields = value;
             }
         }
 
@@ -45,17 +70,17 @@ namespace Discord
             Description = description;
             return this;
         }
-        public EmbedBuilder WithUrl(string url)
+        public EmbedBuilder WithUrl(Uri url)
         {
             Url = url;
             return this;
         }
-        public EmbedBuilder WithThumbnailUrl(string thumbnailUrl)
+        public EmbedBuilder WithThumbnailUrl(Uri thumbnailUrl)
         {
             ThumbnailUrl = thumbnailUrl;
             return this;
         }
-        public EmbedBuilder WithImageUrl(string imageUrl)
+        public EmbedBuilder WithImageUrl(Uri imageUrl)
         {
             ImageUrl = imageUrl;
             return this;
@@ -107,7 +132,7 @@ namespace Discord
                 .WithIsInline(false)
                 .WithName(name)
                 .WithValue(value);
-            Fields.Add(field);
+            AddField(field);
             return this;
         }
         public EmbedBuilder AddInlineField(string name, object value)
@@ -116,11 +141,16 @@ namespace Discord
                 .WithIsInline(true)
                 .WithName(name)
                 .WithValue(value);
-            Fields.Add(field);
+            AddField(field);
             return this;
         }
         public EmbedBuilder AddField(EmbedFieldBuilder field)
         {
+            if (Fields.Count >= MaxFieldCount)
+            {
+                throw new ArgumentException($"Field count must be less than or equal to {MaxFieldCount}.", nameof(field));
+            }
+
             Fields.Add(field);
             return this;
         }
@@ -128,7 +158,7 @@ namespace Discord
         {
             var field = new EmbedFieldBuilder();
             action(field);
-            Fields.Add(field);
+            this.AddField(field);
             return this;
         }
 
@@ -140,6 +170,12 @@ namespace Discord
             for (int i = 0; i < Fields.Count; i++)
                 fields.Add(Fields[i].Build());
             _embed.Fields = fields.ToImmutable();
+
+            if (_embed.Length > MaxEmbedLength)
+            {
+                throw new InvalidOperationException($"Total embed length must be less than or equal to {MaxEmbedLength}");
+            }
+
             return _embed;
         }
         public static implicit operator Embed(EmbedBuilder builder) => builder?.Build();
@@ -149,9 +185,32 @@ namespace Discord
     {
         private EmbedField _field;
 
-        public string Name { get { return _field.Name; } set { _field.Name = value; } }
-        public object Value { get { return _field.Value; } set { _field.Value = value.ToString(); } }
-        public bool IsInline { get { return _field.Inline; } set { _field.Inline = value; } }
+        public const int MaxFieldNameLength = 256;
+        public const int MaxFieldValueLength = 1024;
+
+        public string Name
+        {
+            get => _field.Name;
+            set
+            {
+                if (string.IsNullOrEmpty(value)) throw new ArgumentException($"Field name must not be null or empty.", nameof(Name));
+                if (value.Length > MaxFieldNameLength) throw new ArgumentException($"Field name length must be less than or equal to {MaxFieldNameLength}.", nameof(Name));
+                _field.Name = value;
+            }
+        }
+
+        public object Value
+        {
+            get => _field.Value;
+            set
+            {
+                var stringValue = value.ToString();
+                if (string.IsNullOrEmpty(stringValue)) throw new ArgumentException($"Field value must not be null or empty.", nameof(Value));
+                if (stringValue.Length > MaxFieldValueLength) throw new ArgumentException($"Field value length must be less than or equal to {MaxFieldValueLength}.", nameof(Value));
+                _field.Value = stringValue;
+            }
+        }
+        public bool IsInline { get => _field.Inline; set { _field.Inline = value; } }
 
         public EmbedFieldBuilder()
         {
@@ -182,9 +241,19 @@ namespace Discord
     {
         private EmbedAuthor _author;
 
-        public string Name { get { return _author.Name; } set { _author.Name = value; } }
-        public string Url { get { return _author.Url; } set { _author.Url = value; } }
-        public string IconUrl { get { return _author.IconUrl; } set { _author.IconUrl = value; } }
+        public const int MaxAuthorNameLength = 256;
+
+        public string Name
+        {
+            get => _author.Name;
+            set
+            {
+                if (value?.Length > MaxAuthorNameLength) throw new ArgumentException($"Author name length must be less than or equal to {MaxAuthorNameLength}.", nameof(Name));
+                _author.Name = value;
+            }
+        }
+        public Uri Url { get => _author.Url; set { _author.Url = value; } }
+        public Uri IconUrl { get => _author.IconUrl; set { _author.IconUrl = value; } }
 
         public EmbedAuthorBuilder()
         {
@@ -196,12 +265,12 @@ namespace Discord
             Name = name;
             return this;
         }
-        public EmbedAuthorBuilder WithUrl(string url)
+        public EmbedAuthorBuilder WithUrl(Uri url)
         {
             Url = url;
             return this;
         }
-        public EmbedAuthorBuilder WithIconUrl(string iconUrl)
+        public EmbedAuthorBuilder WithIconUrl(Uri iconUrl)
         {
             IconUrl = iconUrl;
             return this;
@@ -215,8 +284,18 @@ namespace Discord
     {
         private EmbedFooter _footer;
 
-        public string Text { get { return _footer.Text; } set { _footer.Text = value; } }
-        public string IconUrl { get { return _footer.IconUrl; } set { _footer.IconUrl = value; } }
+        public const int MaxFooterTextLength = 2048;
+
+        public string Text
+        {
+            get => _footer.Text;
+            set
+            {
+                if (value?.Length > MaxFooterTextLength) throw new ArgumentException($"Footer text length must be less than or equal to {MaxFooterTextLength}.", nameof(Text));
+                _footer.Text = value;
+            }
+        }
+        public Uri IconUrl { get => _footer.IconUrl; set { _footer.IconUrl = value; } }
 
         public EmbedFooterBuilder()
         {
@@ -228,7 +307,7 @@ namespace Discord
             Text = text;
             return this;
         }
-        public EmbedFooterBuilder WithIconUrl(string iconUrl)
+        public EmbedFooterBuilder WithIconUrl(Uri iconUrl)
         {
             IconUrl = iconUrl;
             return this;