fix: ES private fields parsing in SWC (#5964)

4 files changed, 24 insertions, 3 deletions

diff --git a/cli/swc_util.rs b/cli/swc_util.rs
index 968255440..0d1d1ba08 100644
--- a/cli/swc_util.rs
+++ b/cli/swc_util.rs
@@ -32,9 +32,9 @@ use swc_ecma_visit::Visit;
 fn get_default_es_config() -> EsConfig {
   let mut config = EsConfig::default();
   config.num_sep = true;
-  config.class_private_props = false;
-  config.class_private_methods = false;
-  config.class_props = false;
+  config.class_private_props = true;
+  config.class_private_methods = true;
+  config.class_props = true;
   config.export_default_from = true;
   config.export_namespace_from = true;
   config.dynamic_import = true;
diff --git a/cli/tests/es_private_fields.js b/cli/tests/es_private_fields.js
new file mode 100644
index 000000000..b5f83e39c
--- /dev/null
+++ b/cli/tests/es_private_fields.js
@@ -0,0 +1,15 @@
+class Foo {
+  #field = "field";
+
+  setValue(val) {
+    this.#field = val;
+  }
+
+  getValue() {
+    return this.#field;
+  }
+}
+
+const bar = new Foo();
+bar.setValue("PRIVATE");
+console.log(bar.getValue());
diff --git a/cli/tests/es_private_fields.js.out b/cli/tests/es_private_fields.js.out
new file mode 100644
index 000000000..be1970b05
--- /dev/null
+++ b/cli/tests/es_private_fields.js.out
@@ -0,0 +1 @@
+PRIVATE
diff --git a/cli/tests/integration_tests.rs b/cli/tests/integration_tests.rs
index 0a50190d2..6ab204082 100644
--- a/cli/tests/integration_tests.rs
+++ b/cli/tests/integration_tests.rs
@@ -1827,6 +1827,11 @@ itest!(fix_js_imports {
   output: "fix_js_imports.ts.out",
 });
 
+itest!(es_private_fields {
+  args: "run --quiet --reload es_private_fields.js",
+  output: "es_private_fields.js.out",
+});
+
 itest!(proto_exploit {
   args: "run proto_exploit.js",
   output: "proto_exploit.js.out",