From f4313c5d9549b047f00b36645e2e30b92d68217c Mon Sep 17 00:00:00 2001
From: overlookmotel <theoverlookmotel@gmail.com>
Date: Wed, 18 Dec 2024 22:56:20 +0000
Subject: [PATCH] Correct `classes_stack` when nothing to transform

---
 .../src/es2022/class_properties/class.rs      | 37 ++++++++++++++-----
 .../es2022/class_properties/class_details.rs  |  2 +
 2 files changed, 30 insertions(+), 9 deletions(-)

diff --git a/crates/oxc_transformer/src/es2022/class_properties/class.rs b/crates/oxc_transformer/src/es2022/class_properties/class.rs
index bdb6c70f5ce073..6397b77e48a94f 100644
--- a/crates/oxc_transformer/src/es2022/class_properties/class.rs
+++ b/crates/oxc_transformer/src/es2022/class_properties/class.rs
@@ -105,12 +105,6 @@ impl<'a, 'ctx> ClassProperties<'a, 'ctx> {
             }
         }
 
-        // Exit if nothing to transform
-        if instance_prop_count == 0 && !has_static_prop && !has_static_block {
-            self.classes_stack.push(ClassDetails::default());
-            return;
-        }
-
         // Determine if is a class declaration
         let is_declaration = match ctx.ancestor(1) {
             Ancestor::ExportDefaultDeclarationDeclaration(_)
@@ -118,6 +112,17 @@ impl<'a, 'ctx> ClassProperties<'a, 'ctx> {
             grandparent => grandparent.is_via_statement(),
         };
 
+        // Exit if nothing to transform
+        if instance_prop_count == 0 && !has_static_prop && !has_static_block {
+            self.classes_stack.push(ClassDetails {
+                is_declaration,
+                transform_required: false,
+                private_props: None,
+                bindings: ClassBindings::default(),
+            });
+            return;
+        }
+
         // Initialize class binding vars.
         // Static prop in class expression or anonymous `export default class {}` always require
         // temp var for class. Static prop in class declaration doesn't.
@@ -152,6 +157,7 @@ impl<'a, 'ctx> ClassProperties<'a, 'ctx> {
         // Add entry to `classes_stack`
         self.classes_stack.push(ClassDetails {
             is_declaration,
+            transform_required: true,
             private_props: if private_props.is_empty() { None } else { Some(private_props) },
             bindings: class_bindings,
         });
@@ -267,6 +273,13 @@ impl<'a, 'ctx> ClassProperties<'a, 'ctx> {
             return;
         }
 
+        // TODO: Refactor
+        if !class_details.transform_required {
+            debug_assert!(class_details.bindings.temp.is_none());
+            self.classes_stack.pop();
+            return;
+        }
+
         // TODO: Comment explaining why
         class_details.bindings.static_private_fields_use_temp = true;
 
@@ -367,6 +380,13 @@ impl<'a, 'ctx> ClassProperties<'a, 'ctx> {
             return;
         }
 
+        let class_details = self.current_class();
+        if !class_details.transform_required {
+            debug_assert!(class_details.bindings.temp.is_none());
+            self.classes_stack.pop();
+            return;
+        }
+
         // Transform static properties, remove static and instance properties, and move computed keys
         // to before class
         self.transform_class_on_exit_impl(class, ctx);
@@ -393,9 +413,8 @@ impl<'a, 'ctx> ClassProperties<'a, 'ctx> {
             expr_count += private_props.len();
         }
 
-        if expr_count == 0 {
-            return;
-        }
+        // TODO: Why is this assertion failing sometimes?
+        // debug_assert!(expr_count > 0);
 
         expr_count += 1 + usize::from(class_details.bindings.temp.is_some());
 
diff --git a/crates/oxc_transformer/src/es2022/class_properties/class_details.rs b/crates/oxc_transformer/src/es2022/class_properties/class_details.rs
index e77f85f0312771..91dc6c764fd854 100644
--- a/crates/oxc_transformer/src/es2022/class_properties/class_details.rs
+++ b/crates/oxc_transformer/src/es2022/class_properties/class_details.rs
@@ -12,6 +12,8 @@ use super::{ClassBindings, ClassProperties, FxIndexMap};
 pub(super) struct ClassDetails<'a> {
     /// `true` for class declaration, `false` for class expression
     pub is_declaration: bool,
+    /// `true` if class requires no transformation
+    pub transform_required: bool,
     /// Private properties.
     /// Mapping private prop name to binding for temp var.
     /// This is then used as lookup when transforming e.g. `this.#x`.