Handle overflow checks in central locations

src/builder/create_embed.rs

@@ -203,13 +203,13 @@ impl<'a> CreateEmbed<'a> {
     }
 
     #[cfg(feature = "http")]
-    pub(super) fn check_length(&self) -> Result<()> {
+    pub(super) fn get_length(&self) -> usize {
         let mut length = 0;
-        if let Some(ref author) = self.author {
+        if let Some(author) = &self.author {
             length += author.name.chars().count();
         }
 
-        if let Some(ref description) = self.description {
+        if let Some(description) = &self.description {
             length += description.chars().count();
         }
 
@@ -218,16 +218,15 @@ impl<'a> CreateEmbed<'a> {
             length += field.value.chars().count();
         }
 
-        if let Some(ref footer) = self.footer {
+        if let Some(footer) = &self.footer {
             length += footer.text.chars().count();
         }
 
-        if let Some(ref title) = self.title {
+        if let Some(title) = &self.title {
             length += title.chars().count();
         }
 
-        super::check_overflow(length, crate::constants::EMBED_MAX_LENGTH)
-            .map_err(|overflow| Error::Model(ModelError::EmbedTooLarge(overflow)))
+        length
     }
 }
 

src/builder/create_interaction_response.rs

@@ -1,7 +1,7 @@
 use std::borrow::Cow;
 
 #[cfg(feature = "http")]
-use super::{check_overflow, Builder};
+use super::Builder;
 use super::{
     CreateActionRow,
     CreateAllowedMentions,
@@ -10,8 +10,6 @@ use super::{
     EditAttachments,
 };
 #[cfg(feature = "http")]
-use crate::constants;
-#[cfg(feature = "http")]
 use crate::http::CacheHttp;
 use crate::internal::prelude::*;
 use crate::json::{self, json};
@@ -101,26 +99,15 @@ impl serde::Serialize for CreateInteractionResponse<'_> {
 
 impl CreateInteractionResponse<'_> {
     #[cfg(feature = "http")]
-    fn check_length(&self) -> Result<()> {
+    fn check_length(&self) -> Result<(), ModelError> {
         if let CreateInteractionResponse::Message(data)
         | CreateInteractionResponse::Defer(data)
         | CreateInteractionResponse::UpdateMessage(data) = self
         {
-            if let Some(content) = &data.content {
-                check_overflow(content.chars().count(), constants::MESSAGE_CODE_LIMIT)
-                    .map_err(|overflow| Error::Model(ModelError::MessageTooLong(overflow)))?;
-            }
-
-            if let Some(embeds) = &data.embeds {
-                check_overflow(embeds.len(), constants::EMBED_MAX_COUNT)
-                    .map_err(|_| Error::Model(ModelError::EmbedAmount))?;
-
-                for embed in embeds.iter() {
-                    embed.check_length()?;
-                }
-            }
+            super::check_lengths(data.content.as_deref(), data.embeds.as_deref(), 0)
+        } else {
+            Ok(())
         }
-        Ok(())
     }
 }
 

src/builder/create_interaction_response_followup.rs

@@ -1,7 +1,7 @@
 use std::borrow::Cow;
 
 #[cfg(feature = "http")]
-use super::{check_overflow, Builder};
+use super::Builder;
 use super::{
     CreateActionRow,
     CreateAllowedMentions,
@@ -10,8 +10,6 @@ use super::{
     EditAttachments,
 };
 #[cfg(feature = "http")]
-use crate::constants;
-#[cfg(feature = "http")]
 use crate::http::CacheHttp;
 #[cfg(feature = "http")]
 use crate::internal::prelude::*;
@@ -44,19 +42,8 @@ impl<'a> CreateInteractionResponseFollowup<'a> {
     }
 
     #[cfg(feature = "http")]
-    fn check_length(&self) -> Result<()> {
-        if let Some(content) = &self.content {
-            check_overflow(content.chars().count(), constants::MESSAGE_CODE_LIMIT)
-                .map_err(|overflow| Error::Model(ModelError::MessageTooLong(overflow)))?;
-        }
-
-        check_overflow(self.embeds.len(), constants::EMBED_MAX_COUNT)
-            .map_err(|_| Error::Model(ModelError::EmbedAmount))?;
-        for embed in self.embeds.iter() {
-            embed.check_length()?;
-        }
-
-        Ok(())
+    fn check_length(&self) -> Result<(), ModelError> {
+        super::check_lengths(self.content.as_deref(), Some(&self.embeds), 0)
     }
 
     /// Set the content of the message.

src/builder/create_message.rs

@@ -1,7 +1,7 @@
 use std::borrow::Cow;
 
 #[cfg(feature = "http")]
-use super::{check_overflow, Builder};
+use super::Builder;
 use super::{
     CreateActionRow,
     CreateAllowedMentions,
@@ -10,8 +10,6 @@ use super::{
     EditAttachments,
 };
 #[cfg(feature = "http")]
-use crate::constants;
-#[cfg(feature = "http")]
 use crate::http::CacheHttp;
 #[cfg(feature = "http")]
 use crate::internal::prelude::*;
@@ -82,22 +80,8 @@ impl<'a> CreateMessage<'a> {
     }
 
     #[cfg(feature = "http")]
-    fn check_length(&self) -> Result<()> {
-        if let Some(content) = &self.content {
-            check_overflow(content.chars().count(), constants::MESSAGE_CODE_LIMIT)
-                .map_err(|overflow| Error::Model(ModelError::MessageTooLong(overflow)))?;
-        }
-
-        check_overflow(self.embeds.len(), constants::EMBED_MAX_COUNT)
-            .map_err(|_| Error::Model(ModelError::EmbedAmount))?;
-        for embed in self.embeds.iter() {
-            embed.check_length()?;
-        }
-
-        check_overflow(self.sticker_ids.len(), constants::STICKER_MAX_COUNT)
-            .map_err(|_| Error::Model(ModelError::StickerAmount))?;
-
-        Ok(())
+    fn check_length(&self) -> Result<(), ModelError> {
+        super::check_lengths(self.content.as_deref(), Some(&self.embeds), self.sticker_ids.len())
     }
 
     /// Set the content of the message.
@@ -292,7 +276,7 @@ impl Builder for CreateMessage<'_> {
     ///
     /// # Errors
     ///
-    /// Returns a [`ModelError::MessageTooLong`] if the message contents are over the above limits.
+    /// Returns a [`ModelError::TooLarge`] if the message contents are over the above limits.
     ///
     /// If the `cache` is enabled, returns a [`ModelError::InvalidPermissions`] if the current user
     /// lacks permission. Otherwise returns [`Error::Http`], as well as if invalid data is given.

src/builder/create_webhook.rs

@@ -66,8 +66,8 @@ impl<'a> Builder for CreateWebhook<'a> {
     /// If the `cache` is enabled, returns [`ModelError::InvalidChannelType`] if the corresponding
     /// channel is not of type [`Text`] or [`News`].
     ///
-    /// If the provided name is less than 2 characters, returns [`ModelError::NameTooShort`]. If it
-    /// is more than 100 characters, returns [`ModelError::NameTooLong`].
+    /// If the provided name is less than 2 characters, returns [`ModelError::TooSmall`]. If it
+    /// is more than 100 characters, returns [`ModelError::TooLarge`].
     ///
     /// Returns a [`Error::Http`] if the current user lacks permission, or if invalid data is
     /// given.
@@ -92,11 +92,8 @@ impl<'a> Builder for CreateWebhook<'a> {
             }
         }
 
-        if self.name.len() < 2 {
-            return Err(Error::Model(ModelError::NameTooShort));
-        } else if self.name.len() > 100 {
-            return Err(Error::Model(ModelError::NameTooLong));
-        }
+        crate::model::error::Minimum::WebhookName.check_underflow(self.name.chars().count())?;
+        crate::model::error::Maximum::WebhookName.check_overflow(self.name.chars().count())?;
 
         cache_http.http().create_webhook(ctx, &self, self.audit_log_reason).await
     }

src/builder/edit_message.rs

@@ -1,7 +1,7 @@
 use std::borrow::Cow;
 
 #[cfg(feature = "http")]
-use super::{check_overflow, Builder};
+use super::Builder;
 use super::{
     CreateActionRow,
     CreateAllowedMentions,
@@ -10,8 +10,6 @@ use super::{
     EditAttachments,
 };
 #[cfg(feature = "http")]
-use crate::constants;
-#[cfg(feature = "http")]
 use crate::http::CacheHttp;
 #[cfg(feature = "http")]
 use crate::internal::prelude::*;
@@ -61,21 +59,8 @@ impl<'a> EditMessage<'a> {
     }
 
     #[cfg(feature = "http")]
-    fn check_length(&self) -> Result<()> {
-        if let Some(content) = &self.content {
-            check_overflow(content.chars().count(), constants::MESSAGE_CODE_LIMIT)
-                .map_err(|overflow| Error::Model(ModelError::MessageTooLong(overflow)))?;
-        }
-
-        if let Some(embeds) = &self.embeds {
-            check_overflow(embeds.len(), constants::EMBED_MAX_COUNT)
-                .map_err(|_| Error::Model(ModelError::EmbedAmount))?;
-            for embed in embeds.iter() {
-                embed.check_length()?;
-            }
-        }
-
-        Ok(())
+    fn check_length(&self) -> Result<(), ModelError> {
+        super::check_lengths(self.content.as_deref(), self.embeds.as_deref(), 0)
     }
 
     /// Set the content of the message.
@@ -243,7 +228,7 @@ impl Builder for EditMessage<'_> {
     ///
     /// # Errors
     ///
-    /// Returns a [`ModelError::MessageTooLong`] if the message contents are over the above limits.
+    /// Returns a [`ModelError::TooLarge`] if the message contents are over the above limits.
     ///
     /// Returns [`Error::Http`] if the user lacks permission, as well as if invalid data is given.
     ///

src/builder/edit_webhook_message.rs

@@ -1,7 +1,7 @@
 use std::borrow::Cow;
 
 #[cfg(feature = "http")]
-use super::{check_overflow, Builder};
+use super::Builder;
 use super::{
     CreateActionRow,
     CreateAllowedMentions,
@@ -10,8 +10,6 @@ use super::{
     EditAttachments,
 };
 #[cfg(feature = "http")]
-use crate::constants;
-#[cfg(feature = "http")]
 use crate::http::CacheHttp;
 #[cfg(feature = "http")]
 use crate::internal::prelude::*;
@@ -45,21 +43,8 @@ impl<'a> EditWebhookMessage<'a> {
     }
 
     #[cfg(feature = "http")]
-    pub(crate) fn check_length(&self) -> Result<()> {
-        if let Some(content) = &self.content {
-            check_overflow(content.chars().count(), constants::MESSAGE_CODE_LIMIT)
-                .map_err(|overflow| Error::Model(ModelError::MessageTooLong(overflow)))?;
-        }
-
-        if let Some(embeds) = &self.embeds {
-            check_overflow(embeds.len(), constants::EMBED_MAX_COUNT)
-                .map_err(|_| Error::Model(ModelError::EmbedAmount))?;
-            for embed in embeds.iter() {
-                embed.check_length()?;
-            }
-        }
-
-        Ok(())
+    pub(crate) fn check_length(&self) -> Result<(), ModelError> {
+        super::check_lengths(self.content.as_deref(), self.embeds.as_deref(), 0)
     }
 
     /// Set the content of the message.

src/builder/execute_webhook.rs

@@ -1,7 +1,7 @@
 use std::borrow::Cow;
 
 #[cfg(feature = "http")]
-use super::{check_overflow, Builder};
+use super::Builder;
 use super::{
     CreateActionRow,
     CreateAllowedMentions,
@@ -10,8 +10,6 @@ use super::{
     EditAttachments,
 };
 #[cfg(feature = "http")]
-use crate::constants;
-#[cfg(feature = "http")]
 use crate::http::CacheHttp;
 #[cfg(feature = "http")]
 use crate::internal::prelude::*;
@@ -90,19 +88,8 @@ impl<'a> ExecuteWebhook<'a> {
     }
 
     #[cfg(feature = "http")]
-    fn check_length(&self) -> Result<()> {
-        if let Some(content) = &self.content {
-            check_overflow(content.chars().count(), constants::MESSAGE_CODE_LIMIT)
-                .map_err(|overflow| Error::Model(ModelError::MessageTooLong(overflow)))?;
-        }
-
-        check_overflow(self.embeds.len(), constants::EMBED_MAX_COUNT)
-            .map_err(|_| Error::Model(ModelError::EmbedAmount))?;
-        for embed in self.embeds.iter() {
-            embed.check_length()?;
-        }
-
-        Ok(())
+    fn check_length(&self) -> Result<(), ModelError> {
+        super::check_lengths(self.content.as_deref(), Some(&self.embeds), 0)
     }
 
     /// Override the default avatar of the webhook with an image URL.

src/builder/mod.rs

@@ -11,6 +11,8 @@
 use crate::http::CacheHttp;
 #[cfg(feature = "http")]
 use crate::internal::prelude::*;
+#[cfg(feature = "http")]
+use crate::model::ModelError;
 
 /// Common trait for all HTTP request builders in this module.
 #[cfg(feature = "http")]
@@ -28,12 +30,26 @@ pub trait Builder {
 }
 
 #[cfg(feature = "http")]
-pub(crate) fn check_overflow(len: usize, max: usize) -> StdResult<(), usize> {
-    if len > max {
-        Err(len - max)
-    } else {
-        Ok(())
+pub(crate) fn check_lengths(
+    content: Option<&str>,
+    embeds: Option<&[CreateEmbed<'_>]>,
+    stickers: usize,
+) -> StdResult<(), ModelError> {
+    use crate::model::error::Maximum;
+
+    if let Some(content) = content {
+        Maximum::MessageLength.check_overflow(content.chars().count())?;
     }
+
+    if let Some(embeds) = embeds {
+        Maximum::EmbedCount.check_overflow(embeds.len())?;
+
+        for embed in embeds {
+            Maximum::EmbedLength.check_overflow(embed.get_length())?;
+        }
+    }
+
+    Maximum::StickerCount.check_overflow(stickers)
 }
 
 mod add_member;

src/constants.rs

@@ -1,5 +1,7 @@
 //! A set of constants used by the library.
 
+use nonmax::NonMaxU16;
+
 /// The maximum length of the textual size of an embed.
 pub const EMBED_MAX_LENGTH: usize = 6000;
 
@@ -19,7 +21,10 @@ pub const LARGE_THRESHOLD: u8 = 250;
 pub const MESSAGE_CODE_LIMIT: usize = 2000;
 
 /// The maximum number of members the bot can fetch at once
-pub const MEMBER_FETCH_LIMIT: u64 = 1000;
+pub const MEMBER_FETCH_LIMIT: NonMaxU16 = match NonMaxU16::new(1000) {
+    Some(m) => m,
+    None => unreachable!(),
+};
 
 /// The [UserAgent] sent along with every request.
 ///