From 9324d0730d3293ec5938b80cf93db836070da7bc Mon Sep 17 00:00:00 2001
From: Denis Bezrukov <6227442+denbezrukov@users.noreply.github.com>
Date: Tue, 19 Sep 2023 22:42:09 +0300
Subject: [PATCH 1/2] refactor(formatter): Use OnceCell in Memoized

---
 crates/biome_formatter/src/format_extensions.rs | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/crates/biome_formatter/src/format_extensions.rs b/crates/biome_formatter/src/format_extensions.rs
index 21c99c29c50b..dbcfaade30eb 100644
--- a/crates/biome_formatter/src/format_extensions.rs
+++ b/crates/biome_formatter/src/format_extensions.rs
@@ -1,5 +1,5 @@
 use crate::prelude::*;
-use std::cell::RefCell;
+use std::cell::OnceCell;
 use std::marker::PhantomData;
 use std::ops::Deref;
 
@@ -70,7 +70,7 @@ impl<T, Context> MemoizeFormat<Context> for T where T: Format<Context> {}
 #[derive(Debug)]
 pub struct Memoized<F, Context> {
     inner: F,
-    memory: RefCell<Option<FormatResult<Option<FormatElement>>>>,
+    memory: OnceCell<FormatResult<Option<FormatElement>>>,
     options: PhantomData<Context>,
 }
 
@@ -81,7 +81,7 @@ where
     fn new(inner: F) -> Self {
         Self {
             inner,
-            memory: RefCell::new(None),
+            memory: OnceCell::new(),
             options: PhantomData,
         }
     }
@@ -143,10 +143,7 @@ where
     ///
     /// ```
     pub fn inspect(&mut self, f: &mut Formatter<Context>) -> FormatResult<&[FormatElement]> {
-        let result = self
-            .memory
-            .get_mut()
-            .get_or_insert_with(|| f.intern(&self.inner));
+        let result = self.memory.get_or_init(|| f.intern(&self.inner));
 
         match result.as_ref() {
             Ok(Some(FormatElement::Interned(interned))) => Ok(interned.deref()),
@@ -162,8 +159,7 @@ where
     F: Format<Context>,
 {
     fn fmt(&self, f: &mut Formatter<Context>) -> FormatResult<()> {
-        let mut memory = self.memory.borrow_mut();
-        let result = memory.get_or_insert_with(|| f.intern(&self.inner));
+        let result = self.memory.get_or_init(|| f.intern(&self.inner));
 
         match result {
             Ok(Some(elements)) => {

From 2bfca2b202075f7c6f63eb0f4fc59627416089ac Mon Sep 17 00:00:00 2001
From: Denis Bezrukov <6227442+denbezrukov@users.noreply.github.com>
Date: Tue, 19 Sep 2023 22:45:25 +0300
Subject: [PATCH 2/2] refactor(formatter): Use OnceCell in Memoized

---
 CHANGELOG.md                                     | 4 ++++
 website/src/content/docs/internals/changelog.mdx | 4 ++++
 2 files changed, 8 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index aef18e0306f7..c59971b14b3b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -25,6 +25,10 @@ Read our [guidelines for writing a good changelog entry](https://github.com/biom
 ### Configuration
 ### Editors
 ### Formatter
+
+#### Enhancements
+- Use `OnceCell` for the Memoized memory because that's what the `RefCell<Option>` implemented. Contributed by @denbezrukov
+
 ### JavaScript APIs
 ### Linter
 
diff --git a/website/src/content/docs/internals/changelog.mdx b/website/src/content/docs/internals/changelog.mdx
index 1b0e78d2c762..363f0e7f683b 100644
--- a/website/src/content/docs/internals/changelog.mdx
+++ b/website/src/content/docs/internals/changelog.mdx
@@ -31,6 +31,10 @@ Read our [guidelines for writing a good changelog entry](https://github.com/biom
 ### Configuration
 ### Editors
 ### Formatter
+
+#### Enhancements
+- Use `OnceCell` for the Memoized memory because that's what the `RefCell<Option>` implemented. Contributed by @denbezrukov
+
 ### JavaScript APIs
 ### Linter