TypeError: undefined is not a function

var fs = require("fs");

function mergeValues(values, content) {
  // cycle over the keys 
    for (var key in values) {
      // replace all {{key}} with the values object
      content = content.replace("{{" + key + "}}", values[key]);
    }

  //return merged content
  return content;
}
// Function that handles the reading of files to the templates that we have and merge in values
  // read from file and get a string 
    // merge values in to string

function view(templateName, values, response) {
  // read from the template files
  var fileContents = fs.readFileSync('./views/' + templateName + '.html', {enconding: "utf8"});
  // Insert Values in to the content
  fileContents = mergeValues(values, fileContents);
  // Write out the contents to the response
  response.write(fileContents);
}

module.exports.view = view;