deep flatten nested object

flatten object.js

const flatten = (obj, prefix = '') => {

	return Object.keys(obj).reduce((acc, key) => {
	    const value = obj[key]
	    const prefixedKey = `${prefix}${prefix !== '' ? '.' : ''}${key}`
	    
	    if (typeof value === "string") {
		    return { 
			    ...acc, 
			    prefixedKey]: curr
		    };
	    }
	    
            if (value && value.constructor.name.toLowerCase() === "object") {
    	        return {
		    ...acc,
		    ...flatten(value, prefixedKey)
	    }
        }
    
        return acc
    }, {})
}