Angular method decorator to calcuate the time taken to execute a function

timer.ts

/**
 * Angular method decorator to caculate the time taken to execute a function
 *
 */

export function timer(
  prototype: any,
  name: string,
  descriptor: PropertyDescriptor
) {
  const orig = descriptor.value;
  descriptor.value = function (...args: []) {
    //start the timer
    const start = performance.now();
    // run the function
    orig.apply(this, args);
    // stop the timer
    const stop = performance.now();
    console.log(`Total time taken:`, stop - start);
  };
}


/**
 * How to use it?
 * 
 * @timer
 * getData() {
 *    ......
 * }
 */