Here you can find the source of dasherize()
String.prototype.dasherize = function() { return this.replace(/_/g, "-"); };
String.prototype.dasherize = function() { return this.replace(/_/g, "-"); };
String.prototype.dasherize = function() { return this.gsub(/_/,'-'); };
String.prototype.dasherize = function() { return this.replace(/_/g, '-'); };
String.prototype.dasherize = function() { return this.replace(/_/g, "-"); };