callAfter

Returns a new function that can be called only after calling a specific number of times.

1. Code

/**
 * Creates a function that delays the execution of the provided function until it has been called a specified number of times.
 *
 * @param fn - The function to be called after a certain number of invocations.
 * @param count - The number of times the function needs to be called before it is executed.
 * @returns A new function that delays the execution of the provided function until it has been called a specified number of times.
 */
const callAfter = <T, S extends any[]>(
  fn: (...args: S) => T,
  count: number
): ((...args: S) => T | undefined) => {
  let counter = 0;
  return (...args: S): T | undefined => {
    if (counter < count) {
      counter++;
      return undefined;
    }
    return fn(...args);
  };
};

export default callAfter;

2. Installation

npx @jrtilak/lazykit@latest add callAfter -ts

3. Description

The callAfter function is used to create a new function that can be called only after calling a specific number of times. Before the specified number of calls, the function will always return undefined without executing the original function.

4. Props

Prop

Type

Default Value

function*Function---

count*number---

5. Examples

import callAfter from ".";

const fn = (x: number) => x + 1;

const callAfterFn = callAfter(fn, 2);

const result1 = callAfterFn(1);
// Expected Output: undefined

const result2 = callAfterFn(2);
// Expected Output: undefined

const result3 = callAfterFn(3);
// Expected Output: 4 : as the function `fn` has been called twice already.