Super simple JS templates with String.prototype.tmpl using Ruby/coffeeScript syntax

string.tmpl.js

String.prototype.tmpl = function(obj){
	var str, keys, _do;
	
	//store string
	str = this.toString();
	
	//if no object just return string
	if(!obj || typeof obj !== "object"){
		return str;
	}
	
	//get keys in object
	keys = Object.keys(obj);
	
	//loop through keys and replace place holders
	_do = function(key){
		var rgx = new RegExp("#{"+key+"}", "g");
		str = str.replace(rgx, obj[key]);
	};
	
	keys.forEach(_do);
	
	return str;
}


//just a simple test
function test(){
	var tests, template, report,  assert;
	
	tests = [];
	resultStr = "string : #{str}\n"+
			    "object : #{obj}\n"+
			    "Should be : #{result}\n"+
			    "Passed : #{passed}\n\n";
			
	report = "";
	
	assert = function(test){		
		test.result = test.str.tmpl(test.obj);
		test.passed = test.result === test.should_be;
		test.obj = JSON.stringify(test.obj);
		report += resultStr.tmpl(test);	
	};
	
	tests.push({
		str : "Hello, #{value}", 
		obj : { value : "world" }, 
		should_be : "Hello, world"
	});

	tests.push({
		str : "Welcome #{first_name} #{last_name}!", 
		obj : { first_name : "Stephen", last_name : "Rhyne" }, 
		should_be : "Welcome Stephen Rhyne"
	});
	
	tests.forEach(assert);
	
	console.log(report);
	
}
//was going to use anon but node.js console didn't like it! 	
test();