A problem about x-www-form-urlencoded

[JoYous-SUN]

my code

const bodyparser = require('koa-bodyparser');
const json = require('koa-json');

app.use(bodyparser({
  enableTypes:['json', 'form', 'text']
}));
app.use(json());

//router
router.post('/abc', async (ctx) => {
  console.log(ctx.request.body, 'body');
  ctx.body = ctx.request.body;
});

when i request '/abc':

content-type is application/x-www-form-urlencoded

request-body
data[template_col][p_price_value][taxes_by_distance_serial_interval][intervals][0][begin]: 0

then ctx.request.body is:

{
    "data": {
        "template_col": {
            "p_price_value": {
                "taxes_by_distance_serial_interval": {
                    "intervals": [
                        {
                            "[begin]": "1"
                        }
                    ]
                }
            }
        }
    }
}

why not

 "intervals": [
     { "begin": "1" }
 ]

But expressjs/bodyparser is okay...

[JoYous-SUN]

resolve:

app.use(bodyparser({
  enableTypes:['json', 'form', 'text'],
  queryString: {
    depth: Infinity
  }
}));