setup-node/node_modules/handlebars/lib/handlebars/helpers/log.js

export default function(instance) {
  instance.registerHelper('log', function(/* message, options */) {
    let args = [undefined],
        options = arguments[arguments.length - 1];
    for (let i = 0; i < arguments.length - 1; i++) {
      args.push(arguments[i]);
    }

    let level = 1;
    if (options.hash.level != null) {
      level = options.hash.level;
    } else if (options.data && options.data.level != null) {
      level = options.data.level;
    }
    args[0] = level;

    instance.log(... args);
  });
}