fix(transformer/class-properties): transform this in static prop initializers

crates/oxc_transformer/src/es2022/class_properties/class.rs

@@ -444,9 +444,12 @@ impl<'a, 'ctx> ClassProperties<'a, 'ctx> {
         prop: &mut PropertyDefinition<'a>,
         ctx: &mut TraverseCtx<'a>,
     ) {
-        // Get value
+        // Get value, and transform it to replace `this` with reference to class name
         let value = match &mut prop.value {
-            Some(value) => ctx.ast.move_expression(value),
+            Some(value) => {
+                self.transform_static_initializer(value, ctx);
+                ctx.ast.move_expression(value)
+            }
             None => ctx.ast.void_0(SPAN),
         };
 

crates/oxc_transformer/src/es2022/class_properties/mod.rs

@@ -155,6 +155,7 @@ use crate::TransformCtx;
 mod class;
 mod constructor;
 mod private;
+mod static_prop;
 mod utils;
 
 type FxIndexMap<K, V> = IndexMap<K, V, BuildHasherDefault<FxHasher>>;

crates/oxc_transformer/src/es2022/class_properties/static_prop.rs

@@ -0,0 +1,115 @@
+//! ES2022: Class Properties
+//! Transform of static property initializers.
+
+use oxc_ast::{
+    ast::*,
+    visit::{walk_mut, VisitMut},
+};
+use oxc_syntax::scope::ScopeFlags;
+use oxc_traverse::{BoundIdentifier, TraverseCtx};
+
+use super::{ClassName, ClassProperties};
+
+impl<'a, 'ctx> ClassProperties<'a, 'ctx> {
+    /// Transform any `this` in static property initializer to reference to class name.
+    pub(super) fn transform_static_initializer(
+        &mut self,
+        value: &mut Expression<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        // TODO: Insert temp var if class binding is mutated.
+
+        let ClassName::Binding(class_name_binding) = &self.class_name else {
+            // Binding is initialized in 1st pass in `transform_class` when a static prop is found
+            unreachable!();
+        };
+
+        let mut replacer = StaticInitializerVisitor::new(class_name_binding, ctx);
+        replacer.visit_expression(value);
+    }
+}
+
+struct StaticInitializerVisitor<'a, 'v> {
+    class_name_binding: &'v BoundIdentifier<'a>,
+    ctx: &'v mut TraverseCtx<'a>,
+}
+
+impl<'a, 'v> StaticInitializerVisitor<'a, 'v> {
+    fn new(class_name_binding: &'v BoundIdentifier<'a>, ctx: &'v mut TraverseCtx<'a>) -> Self {
+        Self { class_name_binding, ctx }
+    }
+}
+
+impl<'a, 'v> VisitMut<'a> for StaticInitializerVisitor<'a, 'v> {
+    #[inline]
+    fn visit_expression(&mut self, expr: &mut Expression<'a>) {
+        match expr {
+            Expression::ThisExpression(this_expr) => {
+                let span = this_expr.span;
+                self.replace_this_with_class_name(expr, span);
+                return;
+            }
+            Expression::UnaryExpression(unary_expr) => {
+                if unary_expr.operator == UnaryOperator::Delete
+                    && matches!(&unary_expr.argument, Expression::ThisExpression(_))
+                {
+                    let span = unary_expr.span;
+                    self.replace_delete_this_with_true(expr, span);
+                    return;
+                }
+            }
+            _ => {}
+        }
+
+        walk_mut::walk_expression(self, expr);
+    }
+
+    // Stop traversing where scope of current `this` ends
+    #[inline]
+    fn visit_function(&mut self, _func: &mut Function<'a>, _flags: ScopeFlags) {}
+
+    #[inline]
+    fn visit_static_block(&mut self, _block: &mut StaticBlock) {}
+
+    #[inline]
+    fn visit_ts_module_block(&mut self, _block: &mut TSModuleBlock<'a>) {}
+
+    #[inline]
+    fn visit_property_definition(&mut self, prop: &mut PropertyDefinition<'a>) {
+        // `this` in computed key of property or method refers to `this` of parent class.
+        // So visit computed `key`, but not `value`.
+        // ```js
+        // class Outer {
+        //   static prop = class Inner { [this] = 1; };
+        // }
+        // ```
+        // Don't visit `type_annotation` field because can't contain `this`.
+        // TODO: Are decorators in scope?
+        self.visit_decorators(&mut prop.decorators);
+        if prop.computed {
+            self.visit_property_key(&mut prop.key);
+        }
+    }
+
+    #[inline]
+    fn visit_accessor_property(&mut self, prop: &mut AccessorProperty<'a>) {
+        // Visit computed `key` but not `value`, for same reasons as `visit_property_definition` above.
+        // TODO: Are decorators in scope?
+        self.visit_decorators(&mut prop.decorators);
+        if prop.computed {
+            self.visit_property_key(&mut prop.key);
+        }
+    }
+}
+
+impl<'a, 'v> StaticInitializerVisitor<'a, 'v> {
+    /// Replace `this` with reference to class name binding.
+    fn replace_this_with_class_name(&mut self, expr: &mut Expression<'a>, span: Span) {
+        *expr = self.class_name_binding.create_spanned_read_expression(span, self.ctx);
+    }
+
+    /// Replace `delete this` with `true`.
+    fn replace_delete_this_with_true(&self, expr: &mut Expression<'a>, span: Span) {
+        *expr = self.ctx.ast.expression_boolean_literal(span, true);
+    }
+}

tasks/transform_conformance/snapshots/babel.snap.md

@@ -1,6 +1,6 @@
 commit: 54a8389f
 
-Passed: 405/846
+Passed: 406/846
 
 # All Passed:
 * babel-plugin-transform-class-static-block
@@ -276,7 +276,7 @@ x Output mismatch
 x Output mismatch
 
 
-# babel-plugin-transform-class-properties (78/264)
+# babel-plugin-transform-class-properties (79/264)
 * assumption-constantSuper/complex-super-class/input.js
 x Output mismatch
 
@@ -791,9 +791,6 @@ x Output mismatch
 * public/delete-super-property/input.js
 x Output mismatch
 
-* public/delete-this/input.js
-x Output mismatch
-
 * public/derived-multiple-supers/input.js
 x Output mismatch