now rename in variant overlap rename in enum

src/utils/parsers.rs

@@ -4,6 +4,7 @@ pub use teloxide_macros::BotCommand;
 /// Example:
 /// ```
 /// use teloxide::utils::{parse_command_into_enum, BotCommand};
+/// #[command(rename = "lowercase")]
 /// #[derive(BotCommand, PartialEq, Debug)]
 /// enum TelegramAdminCommand {
 ///     Ban,
@@ -25,6 +26,7 @@ pub trait BotCommand: Sized {
 /// Example:
 /// ```
 /// use teloxide::utils::{parse_command_into_enum, BotCommand};
+/// #[command(rename = "lowercase")]
 /// #[derive(BotCommand, PartialEq, Debug)]
 /// enum TelegramAdminCommand {
 ///     Ban,
@@ -108,6 +110,7 @@ mod tests {
 
     #[test]
     fn parse_command_with_args() {
+        #[command(rename = "lowercase")]
         #[derive(BotCommand, Debug, PartialEq)]
         enum DefaultCommands {
             Start,
@@ -122,6 +125,7 @@ mod tests {
 
     #[test]
     fn attribute_prefix() {
+        #[command(rename = "lowercase")]
         #[derive(BotCommand, Debug, PartialEq)]
         enum DefaultCommands {
             #[command(prefix = "!")]
@@ -137,6 +141,7 @@ mod tests {
     
     #[test]
     fn many_attributes() {
+        #[command(rename = "lowercase")]
         #[derive(BotCommand, Debug, PartialEq)]
         enum DefaultCommands {
             #[command(prefix = "!", description = "desc")]
@@ -150,7 +155,7 @@ mod tests {
 
     #[test]
     fn global_attributes() {
-        #[command(prefix = "!")]
+        #[command(prefix = "!", rename = "lowercase")]
         #[derive(BotCommand, Debug, PartialEq)]
         enum DefaultCommands {
             #[command(prefix = "/")]

teloxide-macros/src/attr.rs

@@ -4,7 +4,8 @@ use syn::{Attribute, LitStr, Token};
 
 pub enum BotCommandAttribute {
     Prefix,
-    Description
+    Description,
+    RenameRule
 }
 
 impl Parse for BotCommandAttribute {
@@ -13,6 +14,7 @@ impl Parse for BotCommandAttribute {
         match name_arg.to_string().as_str() {
             "prefix" => Ok(BotCommandAttribute::Prefix),
             "description" => Ok(BotCommandAttribute::Description),
+            "rename" => Ok(BotCommandAttribute::RenameRule),
             _ => Err(syn::Error::new(name_arg.span(), "unexpected argument"))
         }
     }

teloxide-macros/src/command.rs

@@ -1,38 +1,59 @@
 use crate::attr::{Attr, BotCommandAttribute};
 use std::convert::TryFrom;
+use crate::rename_rules::rename_by_rule;
 
 pub struct Command {
     pub prefix: Option<String>,
     pub description: Option<String>,
+    pub name: String,
+    pub renamed: bool,
 }
 
 impl Command {
-    fn from_attrs(prefix: Option<&Attr>, description: Option<&Attr>) -> Self {
-        let prefix = prefix.map(|attr| attr.value());
-        let description = description.map(|attr| attr.value());
+    pub fn try_from(attrs: &[Attr], name: &str) -> Result<Self, String> {
+        let attrs = parse_attrs(attrs)?;
+        let mut new_name = name.to_string();
+        let mut renamed = false;
 
-        Self {
+        let prefix = attrs.prefix;
+        let description = attrs.description;
+        let rename = attrs.rename;
+        if let Some(rename_rule) = rename {
+            new_name = rename_by_rule(name, &rename_rule);
+            renamed = true;
+        }
+        Ok(Self {
             prefix,
-            description
-        }
+            description,
+            name: new_name,
+            renamed,
+        })
     }
 }
 
-impl TryFrom<&[Attr]> for Command {
-    type Error = String;
-
-    fn try_from(attrs: &[Attr]) -> Result<Self, Self::Error> {
-        let mut prefix = None;
-        let mut description = None;
-
-        for attr in attrs {
-            match attr.name() {
-                BotCommandAttribute::Prefix => prefix = Some(attr),
-                BotCommandAttribute::Description => description = Some(attr),
-                _ => return Err(format!("unexpected attribute")),
-            }
-        }
-
-        Ok(Self::from_attrs(prefix, description))
-    }
+struct CommandAttrs {
+    prefix: Option<String>,
+    description: Option<String>,
+    rename: Option<String>
 }
+
+fn parse_attrs(attrs: &[Attr]) -> Result<CommandAttrs, String> {
+    let mut prefix = None;
+    let mut description = None;
+    let mut rename_rule = None;
+
+    for attr in attrs {
+        match attr.name() {
+            BotCommandAttribute::Prefix => prefix = Some(attr.value()),
+            BotCommandAttribute::Description => description = Some(attr.value()),
+            BotCommandAttribute::RenameRule => rename_rule = Some(attr.value()),
+            _ => return Err(format!("unexpected attribute")),
+        }
+    }
+
+    Ok(CommandAttrs {
+        prefix,
+        description,
+        rename: rename_rule
+    })
+}

teloxide-macros/src/enum_attributes.rs

@@ -1,38 +1,57 @@
 use crate::attr::{Attr, BotCommandAttribute};
 use std::convert::TryFrom;
+use crate::rename_rules::rename_by_rule;
 
 pub struct CommandEnum {
     pub prefix: Option<String>,
     pub description: Option<String>,
+    pub rename_rule: Option<String>,
 }
 
 impl CommandEnum {
-    fn from_attrs(prefix: Option<&Attr>, description: Option<&Attr>) -> Self {
-        let prefix = prefix.map(|attr| attr.value());
-        let description = description.map(|attr| attr.value());
+    pub fn try_from(attrs: &[Attr]) -> Result<Self, String> {
+        let attrs = parse_attrs(attrs)?;
 
-        Self {
-            prefix,
-            description
-        }
-    }
-}
-
-impl TryFrom<&[Attr]> for CommandEnum {
-    type Error = String;
-
-    fn try_from(attrs: &[Attr]) -> Result<Self, Self::Error> {
-        let mut prefix = None;
-        let mut description = None;
-
-        for attr in attrs {
-            match attr.name() {
-                BotCommandAttribute::Prefix => prefix = Some(attr),
-                BotCommandAttribute::Description => description = Some(attr),
-                _ => return Err(format!("unexpected attribute")),
+        let prefix = attrs.prefix;
+        let description = attrs.description;
+        let rename = attrs.rename;
+        if let Some(rename_rule) = &rename {
+            match rename_rule.as_str() {
+                "lowercase" => {},
+                _ => return Err(format!("unallowed value")),
             }
         }
-
-        Ok(Self::from_attrs(prefix, description))
+        Ok(Self {
+            prefix,
+            description,
+            rename_rule: rename
+        })
     }
 }
+
+struct CommandAttrs {
+    prefix: Option<String>,
+    description: Option<String>,
+    rename: Option<String>
+}
+
+fn parse_attrs(attrs: &[Attr]) -> Result<CommandAttrs, String> {
+    let mut prefix = None;
+    let mut description = None;
+    let mut rename_rule = None;
+
+    for attr in attrs {
+        match attr.name() {
+            BotCommandAttribute::Prefix => prefix = Some(attr.value()),
+            BotCommandAttribute::Description => description = Some(attr.value()),
+            BotCommandAttribute::RenameRule => rename_rule = Some(attr.value()),
+            _ => return Err(format!("unexpected attribute")),
+        }
+    }
+
+    Ok(CommandAttrs {
+        prefix,
+        description,
+        rename: rename_rule
+    })
+}

teloxide-macros/src/lib.rs

@@ -1,6 +1,7 @@
 mod attr;
 mod command;
 mod enum_attributes;
+mod rename_rules;
 
 extern crate proc_macro;
 extern crate syn;
@@ -12,27 +13,24 @@ use crate::command::Command;
 use std::convert::TryFrom;
 use crate::attr::{Attr, VecAttrs};
 use crate::enum_attributes::CommandEnum;
+use crate::rename_rules::rename_by_rule;
+
+macro_rules! get_or_return {
+    ($some:tt) => {
+        match $some {
+            Ok(elem) => elem,
+            Err(e) => return e
+        };
+    }
+}
 
 #[proc_macro_derive(BotCommand, attributes(command))]
 pub fn derive_telegram_command_enum(tokens: TokenStream) -> TokenStream {
     let input = parse_macro_input!(tokens as DeriveInput);
 
-    let data_enum = match &input.data {
-        syn::Data::Enum(data) => data,
-        _ => return compile_error("TelegramBotCommand allowed only for enums")
-    };
+    let data_enum: &syn::DataEnum = get_or_return!(get_enum_data(&input));
 
-    let mut enum_attrs = Vec::new();
-    for attr in &input.attrs {
-        match attr.parse_args::<VecAttrs>() {
-            Ok(mut attrs_) => {
-                enum_attrs.append(attrs_.data.as_mut());
-            },
-            Err(e) => {
-                return compile_error(e.to_compile_error());
-            },
-        }
-    }
+    let mut enum_attrs: Vec<Attr> = get_or_return!(parse_attributes(&input.attrs));
 
     let command_enum = match CommandEnum::try_from(enum_attrs.as_slice()) {
         Ok(command_enum) => command_enum,
@@ -54,14 +52,24 @@ pub fn derive_telegram_command_enum(tokens: TokenStream) -> TokenStream {
                 },
             }
         }
-        match Command::try_from(attrs.as_slice()) {
+        match Command::try_from(attrs.as_slice(), &variant.ident.to_string()) {
             Ok(command) => variant_infos.push(command),
             Err(e) => return compile_error(e),
         }
     }
 
     let variant_ident = variants.iter().map(|variant| &variant.ident);
-    let variant_name = variants.iter().map(|variant| variant.ident.to_string().to_lowercase());
+    let variant_name = variant_infos.iter().map(|info| {
+        if info.renamed {
+            info.name.clone()
+        }
+        else if let Some(rename_rule) = &command_enum.rename_rule {
+            rename_by_rule(&info.name, rename_rule)
+        }
+        else {
+            info.name.clone()
+        }
+    });
     let variant_prefixes = variant_infos.iter().map(|info| {
             if let Some(prefix) = &info.prefix {
                 prefix
@@ -100,6 +108,28 @@ pub fn derive_telegram_command_enum(tokens: TokenStream) -> TokenStream {
     tokens
 }
 
+fn get_enum_data(input: &DeriveInput) -> Result<&syn::DataEnum, TokenStream> {
+    match &input.data {
+        syn::Data::Enum(data) => Ok(data),
+        _ => Err(compile_error("TelegramBotCommand allowed only for enums"))
+    }
+}
+
+fn parse_attributes(input: &Vec<syn::Attribute>) -> Result<Vec<Attr>, TokenStream> {
+    let mut enum_attrs = Vec::new();
+    for attr in &input.attrs {
+        match attr.parse_args::<VecAttrs>() {
+            Ok(mut attrs_) => {
+                enum_attrs.append(attrs_.data.as_mut());
+            },
+            Err(e) => {
+                return Err(compile_error(e.to_compile_error()));
+            },
+        }
+    }
+    Ok(enum_attrs)
+}
+
 fn compile_error<T>(data: T) -> TokenStream
 where
     T: ToTokens

teloxide-macros/src/rename_rules.rs

@@ -0,0 +1,6 @@
+pub fn rename_by_rule(input: &str, rule: &str) -> String {
+    match rule {
+        "lowercase" => input.to_string().to_lowercase(),
+        _ => rule.to_string(),
+    }
+}