Setting nested objects that maintain order into Firebase

setWithImplicitPriorities.js

var traverse = require("traverse");

// Traverse object, calculate priority at each level
// so order is maintained (barf barf barf)
traverse(obj).forEach(function(value) {
    if(this.isRoot) {
        priority = 0;
        
        return;
    }
    
    db.child(this.path.join("/")).setWithPriority(
        this.isLeaf ? value : "placeholder",
        priority
    );
    
    if(this.notLeaf) {
        priority = 0;
    } else {
        priority++;
    }
});