disable automatic use declaration injection

src/lib.rs

@@ -464,4 +464,20 @@ test!(
         <span>inline&nbsp;text</span>
     </div>
     "#
+);
+
+
+test!(
+    Syntax::Es(EsSyntax {
+        jsx: true,
+        ..Default::default()
+    },),
+    |_| TransformVisitor,
+    t36,
+    r#"
+    let x = 10;
+    run(() => {
+        console.log(x + 1);
+    })
+    "#
 );

src/visitor.rs

@@ -3,12 +3,9 @@ use swc_core::{
     common::{util::take::Take, SyntaxContext, DUMMY_SP},
     ecma::{
         ast::{
-            ArrowExpr, BlockStmt, BlockStmtOrExpr, CallExpr, Callee, Expr, ExprOrSpread, ExprStmt,
-            FnDecl, Ident, JSXEmptyExpr, JSXExpr, JSXExprContainer, Lit, Null, ReturnStmt, Stmt,
-            Str, VarDecl,
-            IdentName, JSXAttr, JSXAttrName, JSXAttrValue, JSXElement, JSXElementChild, JSXSpreadChild, MemberExpr, MemberProp
+            ArrowExpr, BlockStmt, BlockStmtOrExpr, CallExpr, Callee, Expr, ExprOrSpread, ExprStmt, FnDecl, Ident, IdentName, JSXAttr, JSXAttrName, JSXAttrValue, JSXElement, JSXElementChild, JSXEmptyExpr, JSXExpr, JSXExprContainer, JSXSpreadChild, Lit, MemberExpr, MemberProp, Null, ReturnStmt, SpanExt, Stmt, Str, VarDecl
         },
-        visit::{Fold, Visit, FoldWith, VisitWith},
+        visit::{Fold, FoldWith, Visit, VisitWith},
     },
 };
 
@@ -26,6 +23,7 @@ impl VariableCollector {
 
 impl Visit for VariableCollector {
     fn visit_ident(&mut self, ident: &Ident) {
+
         // add variable to list if not already present
         if !self.variables.contains(&ident.sym.to_string()) {
             self.variables.push(ident.sym.to_string());
@@ -233,6 +231,8 @@ impl TransformVisitor {
     }
 
     fn transform_transferable_closure(arrow: &ArrowExpr, ctxt: SyntaxContext) -> ArrowExpr {
+        // TODO: enable?
+        return arrow.clone();
         // find all variables used in the arrow function body
         let mut collector = VariableCollector::new();
         arrow.body.visit_with(&mut collector);
@@ -304,6 +304,8 @@ impl TransformVisitor {
     }
 
     fn transform_transferable_call_expr(call: &CallExpr) -> CallExpr {
+        // TODO: enable?
+        return call.clone();
         let arg = TransformVisitor::get_first_arg(call);
 
         match arg.unwrap_parens() {

tests/__swc_snapshots__/src/lib.rs/t3.js

@@ -1,5 +1,4 @@
 run(()=>{
-    use(console, x, y);
     console.log(x + y);
     return x + 1;
 });

tests/__swc_snapshots__/src/lib.rs/t36.js

@@ -0,0 +1,4 @@
+let x = 10;
+run(()=>{
+    console.log(x + 1);
+});

tests/__swc_snapshots__/src/lib.rs/t4.js

@@ -1,4 +1 @@
-run(()=>{
-    use(x);
-    return x + 1;
-});
+run(()=>x + 1);

tests/__swc_snapshots__/src/lib.rs/t5.js

@@ -1,5 +1,4 @@
 run(()=>{
-    use(x, y);
     use(x);
     return x + y;
 });

tests/__swc_snapshots__/src/lib.rs/t6.js

@@ -1,4 +1 @@
-<button onclick:frontend={()=>{
-    use(console, x);
-    return console.log(x);
-}}/>;
+<button onclick:frontend={()=>console.log(x)}/>;

tests/__swc_snapshots__/src/lib.rs/t9.js

@@ -1,4 +1 @@
-<button value:frontend={always(()=>{
-    use(x);
-    return x + 1;
-})}/>;
+<button value:frontend={always(()=>x + 1)}/>;