How to use the coffee-script.helpers function in coffee-script

process: function(src, path) {
    src = babel_jest.process(src, path)
    // CoffeeScript files can be .coffee, .litcoffee, or .coffee.md
    if (coffee.helpers.isCoffee(path)) {
      return coffee.compile(src, {'bare': true});
    }
    return src;
  }
}

process: function(src, path) {
    // CoffeeScript files can be .coffee, .litcoffee, or .coffee.md
    if (coffee.helpers.isCoffee(path)) {
      return coffee.compile(src, {'bare': true});
    }
    return src;
  }
};

process: function(src, path) {
    if (coffee.helpers.isCoffee(path)) {
      return coffee.compile(src, {'bare': true})
    }
    if (path.match(/\.tag$/)) {
      return preamble + compiler.compile(src)
    }
    return src
  }
}

function isCoffee(filePath) {
  return coffee.helpers.isCoffee(filePath)
}

process: (src, path, ...rest) => {
    if (coffee.helpers.isCoffee(path)) {
      const compiled = coffee.compile(src, { bare: true, literate: path.endsWith('.litcoffee') })
      return babelJest.process(compiled, path, ...rest)
    }
    return src
  },
}