Experimenting with Node.js and MongoDb and Mongoose
I came across Mongoose for Node.js. It looks like a promising project but I ran into a bug as soon as I started playing with a simple counter program. The problem is in the implementation QueryPromise's atomic functions. Here is a sample program that updates a counter. The three update forms below should all be identical, only the first seems to work with the version I was playing with.
// Simple test program to show a problem in QueryPromise
// ['inc','set','unset','push','pushAll','addToSet','pop','pull','pullAll']
var sys = require('sys')
var mongoose = require('mongoose/').Mongoose
var db = mongoose.connect('mongodb://localhost/test');
var Simple = mongoose.noSchema('test',db);
Simple.drop();
//should only be one....
var m = new Simple({name:'test', x:0,y:0}).save()
// these should behave the same
Simple.update({name:'test'},{'$inc':{x:1, y:1}}).execute();
Simple.update({name:'test'}).inc({x:1, y:1}).execute();
Simple.update({name:'test'}).inc({x:1}).inc({y:1}).execute();
Simple.find({name:'test'}).each(
function (doc) {
sys.puts(JSON.stringify(doc));
}
).then(
function(){ // promise (execute after query)
Simple.close(); // close event loop
}
);
Here is a fixed version of QueryPromise's atomic functions that place the command and arguments in the correct place.
// atomic similar
['inc','set','unset','push','pushAll',
'addToSet','pop','pull','pullAll'].forEach(function(cmd){
QueryPromise.prototype[cmd] = function(modifier){
if(this.op.name.charAt(0) != 'u') return this;
if(!this.op.args.length) this.op.args.push({},{});
if(this.op.args.length == 1) this.op.args.push({});
for(i in modifier) {
if(!(this.op.args[1]['$'+cmd] instanceof Object)) this.op.args[1]['$'+cmd] = {};
this.op.args[1]['$'+cmd][i] = modifier[i];
}
return this;
}
});
