diff --git a/crates/oxc_prettier/src/format/function.rs b/crates/oxc_prettier/src/format/function.rs
new file mode 100644
index 000000000..855c241b4
--- /dev/null
+++ b/crates/oxc_prettier/src/format/function.rs
@@ -0,0 +1,33 @@
+#[allow(clippy::wildcard_imports)]
+use oxc_ast::ast::*;
+
+use crate::{doc::Doc, ss, Format, Prettier};
+
+impl<'a> Prettier<'a> {
+    pub(super) fn print_function(&mut self, func: &Function<'a>) -> Doc<'a> {
+        let mut parts = self.vec();
+        if let Some(comments) = self.print_leading_comments(func.span) {
+            parts.push(comments);
+        }
+        if func.r#async {
+            parts.push(ss!("async "));
+        }
+        if func.generator {
+            parts.push(ss!("function* "));
+        } else {
+            parts.push(ss!("function "));
+        }
+        if let Some(type_params) = &func.type_parameters {
+            parts.push(type_params.format(self));
+        }
+        if let Some(id) = &func.id {
+            parts.push(self.str(id.name.as_str()));
+        }
+        parts.push(func.params.format(self));
+        if let Some(body) = &func.body {
+            parts.push(ss!(" "));
+            parts.push(body.format(self));
+        }
+        Doc::Array(parts)
+    }
+}
diff --git a/crates/oxc_prettier/src/format/function_parameters.rs b/crates/oxc_prettier/src/format/function_parameters.rs
new file mode 100644
index 000000000..d684773cc
--- /dev/null
+++ b/crates/oxc_prettier/src/format/function_parameters.rs
@@ -0,0 +1,26 @@
+#[allow(clippy::wildcard_imports)]
+use oxc_ast::ast::*;
+
+use crate::{doc::Doc, ss, Format, Prettier};
+
+impl<'a> Prettier<'a> {
+    pub(super) fn print_function_parameters(&mut self, params: &FormalParameters<'a>) -> Doc<'a> {
+        let mut parts = self.vec();
+        parts.push(ss!("("));
+
+        for (i, param) in params.items.iter().enumerate() {
+            parts.push(param.format(self));
+            if i < params.items.len() - 1 {
+                parts.push(ss!(", "));
+            }
+        }
+
+        if let Some(rest) = &params.rest {
+            parts.push(ss!(", "));
+            parts.push(rest.format(self));
+        }
+
+        parts.push(ss!(")"));
+        Doc::Array(parts)
+    }
+}
diff --git a/crates/oxc_prettier/src/format/mod.rs b/crates/oxc_prettier/src/format/mod.rs
index 4ef2f6817..a0c10eb08 100644
--- a/crates/oxc_prettier/src/format/mod.rs
+++ b/crates/oxc_prettier/src/format/mod.rs
@@ -12,6 +12,8 @@ use oxc_ast::ast::*;
 mod binaryish;
 mod block;
 mod call_expression;
+mod function;
+mod function_parameters;
 mod object;
 mod statement;
 mod ternary;
@@ -459,30 +461,7 @@ impl<'a> Format<'a> for VariableDeclarator<'a> {
 
 impl<'a> Format<'a> for Function<'a> {
     fn format(&self, p: &mut Prettier<'a>) -> Doc<'a> {
-        let mut parts = p.vec();
-        if let Some(comments) = p.print_leading_comments(self.span) {
-            parts.push(comments);
-        }
-        if self.r#async {
-            parts.push(ss!("async "));
-        }
-        if self.generator {
-            parts.push(ss!("function* "));
-        } else {
-            parts.push(ss!("function "));
-        }
-        if let Some(type_params) = &self.type_parameters {
-            parts.push(format!(p, type_params));
-        }
-        if let Some(id) = &self.id {
-            parts.push(p.str(id.name.as_str()));
-        }
-        parts.push(self.params.format(p));
-        if let Some(body) = &self.body {
-            parts.push(ss!(" "));
-            parts.push(body.format(p));
-        }
-        Doc::Array(parts)
+        p.print_function(self)
     }
 }
 
@@ -494,20 +473,13 @@ impl<'a> Format<'a> for FunctionBody<'a> {
 
 impl<'a> Format<'a> for FormalParameters<'a> {
     fn format(&self, p: &mut Prettier<'a>) -> Doc<'a> {
-        let mut parts = p.vec();
-        parts.push(ss!("("));
-        parts.extend(self.items.iter().map(|stmt| stmt.format(p)));
-        if let Some(rest) = &self.rest {
-            parts.push(rest.format(p));
-        }
-        parts.push(ss!(")"));
-        Doc::Array(parts)
+        p.print_function_parameters(self)
     }
 }
 
 impl<'a> Format<'a> for FormalParameter<'a> {
     fn format(&self, p: &mut Prettier<'a>) -> Doc<'a> {
-        Doc::Line
+        self.pattern.format(p)
     }
 }
 
@@ -1300,7 +1272,7 @@ impl<'a> Format<'a> for BindingProperty<'a> {
 
 impl<'a> Format<'a> for RestElement<'a> {
     fn format(&self, p: &mut Prettier<'a>) -> Doc<'a> {
-        Doc::Line
+        array!(p, ss!("..."), format!(p, self.argument))
     }
 }