[bug]编写NodeJS代码时不支持``字符

已知如下代码不生效：
```
xxx.com/a.json scriptfile://`
exports.handleRequest = async (ctx, next) => {
ctx.body = `{a: 1}`;
};
`
```

需要将ctx.body = `{a: 1}` 改成 ctx.body = '{a: 1}' 才生效。

Start by reproducing the provided scriptfile:// example with the NodeJS handler and compare the backtick template literal with the single-quoted body. Trace the proxy's handling of the script content; done when the backtick version executes and returns the expected body without requiring the workaround.

Written by the indexing model from the issue text.