Javascript function to create nested array/object with variable input

Question

I'm trying to create a nested array from within a function which currently looks like this:

function browse(url, arrayName) {

    let data2 = [];
    fs.readdir(url, (err, files) => {
        if (err) throw err
        files.forEach(file => {
            try {
                data.push({
                    'name': file,
                    'path': path.join(url, file)
                })
            }
            catch(e) {
                console.log(e)
            }
        })
        data2.push({'images': data})
        res.json(data2)
    })
}

what i want to achieve is that i can pass a string to the function that can be used inside of the array, where it currently is hard coded data2.push({'images': data}) so that a function call like browse('path/to/folder', 'cool images') will output

{ "cool images": 
  { 
    "name": "dog.png",
    "path": "path/to/folder/dog.png"
  },
  { 
    "name": "cat.png",
    "path": "path/to/folder/cat.png"
  }
}

I've tried for a while but I can't seem to achieve this and I am also aware that the output currently isn't even proper JSON format – both of which likely stem from the fact that I don't really know the right JSON syntax. There surely must be a nicer way to achieve nested objects than pushing an array into another array…

I'd greatly appreciate a bump in the right direction!

thanks :~)