fix(transformer): ArrowfunctionExpression's expression is true but ha…

…s more than one body statement

crates/oxc_transformer/src/lib.rs

@@ -39,7 +39,7 @@ use oxc_allocator::{Allocator, Vec};
 use oxc_ast::{ast::*, Trivias};
 use oxc_diagnostics::OxcDiagnostic;
 use oxc_semantic::{ScopeTree, SymbolTable};
-use oxc_span::SourceType;
+use oxc_span::{SourceType, SPAN};
 use oxc_traverse::{traverse_mut, Traverse, TraverseCtx};
 
 pub use crate::{
@@ -284,6 +284,26 @@ impl<'a> Traverse<'a> for Transformer<'a> {
         self.x2_es2016.enter_statements(stmts, ctx);
     }
 
+    fn exit_arrow_function_expression(
+        &mut self,
+        arrow: &mut ArrowFunctionExpression<'a>,
+        ctx: &mut TraverseCtx<'a>,
+    ) {
+        if arrow.expression && arrow.body.statements.len() > 1 {
+            arrow.expression = false;
+
+            let Some(Statement::ExpressionStatement(statement)) = arrow.body.statements.pop()
+            else {
+                unreachable!("arrow function body is never empty")
+            };
+
+            arrow
+                .body
+                .statements
+                .push(ctx.ast.statement_return(SPAN, Some(statement.unbox().expression)));
+        }
+    }
+
     fn exit_statements(&mut self, stmts: &mut Vec<'a, Statement<'a>>, ctx: &mut TraverseCtx<'a>) {
         self.x0_typescript.transform_statements_on_exit(stmts, ctx);
         self.x1_react.transform_statements_on_exit(stmts, ctx);