The following code differs from an example in the documentation only in the content of the template string, but it results in a TypeError.
_.templateSettings = {
interpolate : /\{\{(.+?)\}\}/g
};
var template = _.template("Hello null {{ name }}!");
template({name : "Mustache"});
A TypeError also occurs if the template string contains the text "undefined", probably due to the lack of templateSettings.escape regex.