{"ast_node_type":"function","tokens":[{"end":78,"kind":"keyword","start":0,"text":"fn"}]}
    fn assign_to_eq(file: &SourceFile, offset: TextSize) -> Option<TextEdit> {
    /// `a =$0 b;` removes the semicolon if an expression is valid in this context.
        let binop: ast::BinExpr = find_node_at_offset(file.syntax(), offset)?;