Allowed embeds to be optional in followup messages, to prevent edits …

…deleting them.

src/builder/create_interaction_response_followup.rs

@@ -25,7 +25,8 @@ pub struct CreateInteractionResponseFollowup {
     // [Omitting avatar_url: not supported in interaction followups]
     #[serde(skip_serializing_if = "Option::is_none")]
     tts: Option<bool>,
-    embeds: Vec<CreateEmbed>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    embeds: Option<Vec<CreateEmbed>>,
     #[serde(skip_serializing_if = "Option::is_none")]
     allowed_mentions: Option<CreateAllowedMentions>,
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -48,10 +49,12 @@ impl CreateInteractionResponseFollowup {
                 .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 {
-            embed.check_length()?;
+        if let Some(embeds) = &self.embeds {
+            check_overflow(embeds.len(), constants::EMBED_MAX_COUNT)
+                .map_err(|_| Error::Model(ModelError::EmbedAmount))?;
+            for embed in embeds {
+                embed.check_length()?;
+            }
         }
 
         Ok(())
@@ -101,13 +104,13 @@ impl CreateInteractionResponseFollowup {
 
     /// Adds an embed to the message.
     pub fn add_embed(mut self, embed: CreateEmbed) -> Self {
-        self.embeds.push(embed);
+        self.embeds.get_or_insert_with(Vec::new).push(embed);
         self
     }
 
     /// Adds multiple embeds to the message.
     pub fn add_embeds(mut self, embeds: Vec<CreateEmbed>) -> Self {
-        self.embeds.extend(embeds);
+        self.embeds.get_or_insert_with(Vec::new).extend(embeds);
         self
     }
 
@@ -124,7 +127,7 @@ impl CreateInteractionResponseFollowup {
     /// Calling this multiple times will overwrite the embed list. To append embeds, call
     /// [`Self::add_embeds`] instead.
     pub fn embeds(mut self, embeds: Vec<CreateEmbed>) -> Self {
-        self.embeds = embeds;
+        self.embeds = Some(embeds);
         self
     }