Format Identifier (#5255)

crates/ruff_python_formatter/src/other/arg.rs

@@ -1,7 +1,6 @@
 use crate::prelude::*;
 use crate::FormatNodeRule;
 use ruff_formatter::write;
-use ruff_text_size::{TextLen, TextRange};
 use rustpython_parser::ast::Arg;
 
 #[derive(Default)]
@@ -10,21 +9,13 @@ pub struct FormatArg;
 impl FormatNodeRule<Arg> for FormatArg {
     fn fmt_fields(&self, item: &Arg, f: &mut PyFormatter) -> FormatResult<()> {
         let Arg {
-            range,
+            range: _,
             arg,
             annotation,
             type_comment: _,
         } = item;
-        write!(
+
-            f,
+        arg.format().fmt(f)?;
-            [
-                // The name of the argument
-                source_text_slice(
-                    TextRange::at(range.start(), arg.text_len()),
-                    ContainsNewlines::No
-                )
-            ]
-        )?;
 
         if let Some(annotation) = annotation {
             write!(f, [text(":"), space(), annotation.format()])?;

crates/ruff_python_formatter/src/other/identifier.rs

@@ -0,0 +1,28 @@
+use crate::prelude::*;
+use crate::AsFormat;
+use ruff_formatter::{FormatOwnedWithRule, FormatRefWithRule};
+use rustpython_parser::ast::{Identifier, Ranged};
+
+pub struct FormatIdentifier;
+
+impl FormatRule<Identifier, PyFormatContext<'_>> for FormatIdentifier {
+    fn fmt(&self, item: &Identifier, f: &mut PyFormatter) -> FormatResult<()> {
+        source_text_slice(item.range(), ContainsNewlines::No).fmt(f)
+    }
+}
+
+impl<'ast> AsFormat<PyFormatContext<'ast>> for Identifier {
+    type Format<'a> = FormatRefWithRule<'a, Identifier, FormatIdentifier, PyFormatContext<'ast>>;
+
+    fn format(&self) -> Self::Format<'_> {
+        FormatRefWithRule::new(self, FormatIdentifier)
+    }
+}
+
+impl<'ast> IntoFormat<PyFormatContext<'ast>> for Identifier {
+    type Format = FormatOwnedWithRule<Identifier, FormatIdentifier, PyFormatContext<'ast>>;
+
+    fn into_format(self) -> Self::Format {
+        FormatOwnedWithRule::new(self, FormatIdentifier)
+    }
+}

crates/ruff_python_formatter/src/other/mod.rs

@@ -5,6 +5,7 @@ pub(crate) mod arguments;
 pub(crate) mod comprehension;
 pub(crate) mod decorator;
 pub(crate) mod except_handler_except_handler;
+pub(crate) mod identifier;
 pub(crate) mod keyword;
 pub(crate) mod match_case;
 pub(crate) mod type_ignore_type_ignore;

crates/ruff_python_formatter/src/statement/stmt_function_def.rs

@@ -85,7 +85,7 @@ impl FormatRule<AnyFunctionDefinition<'_>, PyFormatContext<'_>> for FormatAnyFun
             [
                 text("def"),
                 space(),
-                dynamic_text(name.as_str(), None),
+                name.format(),
                 item.arguments().format(),
             ]
         )?;