Fix clippy warnings (#3085)

* Run clippy fix

* Clippy v2

* Make const item static

* Cargo fmt

proc-macros/src/discriminant.rs

@@ -101,14 +101,11 @@ pub fn derive_discriminant_impl(input_item: TokenStream) -> syn::Result<TokenStr
 	let (pattern, value) = is_sub_discriminant
 		.into_iter()
 		.map(|b| {
-			(
-				if b {
-					quote::quote! { (x) }
-				} else {
-					quote::quote! { { .. } }
-				},
-				b.then(|| quote::quote! { (x.to_discriminant()) }).unwrap_or_default(),
-			)
+			if b {
+				(quote::quote! {(x)}, quote::quote! {(x.to_discriminant())})
+			} else {
+				(quote::quote! {{..}}, Default::default())
+			}
 		})
 		.unzip::<_, _, Vec<_>, Vec<_>>();
 	#[cfg(feature = "serde-discriminant")]

proc-macros/src/helpers.rs

@@ -55,7 +55,7 @@ pub fn clean_rust_type_syntax(input: String) -> String {
 				}
 			}
 			'<' => {
-				while let Some(' ') = result.chars().rev().next() {
+				while let Some(' ') = result.chars().next_back() {
 					result.pop();
 				}
 				result.push('<');
@@ -64,7 +64,7 @@ pub fn clean_rust_type_syntax(input: String) -> String {
 				}
 			}
 			'>' => {
-				while let Some(' ') = result.chars().rev().next() {
+				while let Some(' ') = result.chars().next_back() {
 					result.pop();
 				}
 				result.push('>');
@@ -74,7 +74,7 @@ pub fn clean_rust_type_syntax(input: String) -> String {
 			}
 			'-' => {
 				if let Some('>') = chars.peek() {
-					while let Some(' ') = result.chars().rev().next() {
+					while let Some(' ') = result.chars().next_back() {
 						result.pop();
 					}
 					result.push_str(" -> ");
@@ -88,7 +88,7 @@ pub fn clean_rust_type_syntax(input: String) -> String {
 			}
 			':' => {
 				if let Some(':') = chars.peek() {
-					while let Some(' ') = result.chars().rev().next() {
+					while let Some(' ') = result.chars().next_back() {
 						result.pop();
 					}
 				}

proc-macros/src/hierarchical_tree.rs

@@ -47,22 +47,20 @@ pub fn generate_hierarchical_tree(input: TokenStream) -> syn::Result<TokenStream
 						})
 					} else {
 						let error_msg = match fields.unnamed.len() {
-							0 => format!("Remove the unnecessary `()` from the `{}` message enum variant.", variant_type),
+							0 => format!("Remove the unnecessary `()` from the `{variant_type}` message enum variant."),
 							1 => {
 								let field_type = &fields.unnamed.first().unwrap().ty;
 								format!(
-									"The `{}` message should be defined as a struct-style (not tuple-style) enum variant to maintain consistent formatting across all editor messages.\n\
+									"The `{variant_type}` message should be defined as a struct-style (not tuple-style) enum variant to maintain consistent formatting across all editor messages.\n\
 									Replace `{}` with a named field using {{curly braces}} instead of a positional field using (parentheses).",
-									variant_type,
 									field_type.to_token_stream()
 								)
 							}
 							_ => {
 								let field_types = fields.unnamed.iter().map(|f| f.ty.to_token_stream().to_string()).collect::<Vec<_>>().join(", ");
 								format!(
-									"The `{}` message should be defined as a struct-style (not tuple-style) enum variant to maintain consistent formatting across all editor messages.\n\
-									Replace `{}` with named fields using {{curly braces}} instead of positional fields using (parentheses).",
-									variant_type, field_types
+									"The `{variant_type}` message should be defined as a struct-style (not tuple-style) enum variant to maintain consistent formatting across all editor messages.\n\
+									Replace `{field_types}` with named fields using {{curly braces}} instead of positional fields using (parentheses)."
 								)
 							}
 						};