[Rust] How to return multiple Stmts in fold_stmt()?

[alshdavid]

I am using fold_stmt to mutate my AST and want to insert multiple statements.

Initially I tried using fold_expr() because I know there is Expr::from_exprs() which allows me to return multiple Exprs however I need to return a Decl::Var and I couldn't find a way to coerce it into an Expr so I have dropped down to fold_stmt.

impl Fold for MyFolder  {
  fn fold_stmt(
    &mut self,
    stmt: Stmt,
  ) -> Stmt {
    let mut stmt = stmt.fold_children_with(self);
    
    if !stmt_matches_condition(&stmt) { return stmt };

    let var_dec: =  Stmt::Decl(Decl::Var(Box::new(VarDecl { /* ... */  })));
    let call_expr = Stmt::Expr(ExprStmt { span: (), expr: Box::new(Expr::Call(CallExpr { /* ... */) })) });

    // The following is invalid but is there something like this that I can use?
    return Stmt::from_stmts(&[
      Box::new(var_dec),
      Box::new(call_expr ),
    ])
  }
}

I have tried fold_stmts however it never fires and I am unsure why

// input.js
'hello world';
42

impl Fold for MyFolder  {
  fn fold_stmts(
    &mut self,
    stmts: Vec<Stmt>,
  ) -> Vec<Stmt> {
    dbg!(&stmts); // never runs
    return stmts;
  }
}

EDIT:

Obviously a BlockStmt doesn't work as it create a block scope

fn fold_stmt(
  &mut self,
  stmt: Stmt,
) -> Stmt {
  let stmt = stmt.fold_children_with(self);

  return Stmt::Block(BlockStmt { 
    span: Span::default(),
    stmts: vec![
      stmt.clone(),
      stmt.clone()
      ] 
  });
}

[alshdavid]

Ah, fold_stmts only runs for Stmts in nested blocks so I had to do use both fold_stmts and fold_module