function-performer

Performer providing API for debounce, throttle and deduplication functions.

Installation

npm install function-performer

# or
pnpm install function-performer

# or
yarn add function-performer

API

constructor

Type: new (config?: PerformerConfig): Performer

Options

• config — Optional parameter providing the performer configuration.
  • debounce - An optional property that provides a debounce configuration.
    • interval - The time in milliseconds during which the target function execution will be discarded. (default value is 0)
  • throttle - An optional property that provides a throttle configuration.
    • interval - The time in milliseconds during which the target function execution will be blocked. (default value is 0)
  • deduplication - An optional property that provides a deduplication configuration.
    • interval - The time in milliseconds during which duplicate detection will occur after calling the target function. (default value is 0)

Example

import { Performer } from 'function-performer';

const performer = new Performer({
  debounce: { interval: 500 },
  throttle: { interval: 1000 },
  deduplication: { interval: 100 },
});

debounce

Type: (func: DebouncedFunction, ...args: unknown[]) => void

Discards execution of operations performed within the specified interval.

Parameters

• func — A function whose call will be discarded.
• ...args — A set of parameters for the function being performed.

Example

import { Performer } from 'function-performer';

const performer = new Performer({
  debounce: { interval: 1000 },
});

const func = (arg: number) => {
  console.log(arg);
};

performer.debounce(func, 1); // will be discarded
performer.debounce(func, 2); // will be discarded
performer.debounce(func, 3); // logs `3`

setTimeout(() => {
  performer.debounce(func, 4); // logs `4`
}, 2000);

throttle

Type: (func: ThrottledFunction, ...args: unknown[]) => void

Blocks execution of operations performed within the specified interval.

Parameters

• func — A function whose call will be blocked.
• ...args — A set of parameters for the function being performed.

Example

import { Performer } from 'function-performer';

const performer = new Performer({
  // Will only allow one call every 100 milliseconds
  throttle: { interval: 100 },
});

const func = (arg: number) => {
  console.log(arg);
};

let time = 0;
const interval = setInterval(() => {
  if(time === 1000) {
    clearInterval(interval);
    return;
  }

  performer.throttle(func, time); // logs `0`, `100`, `200`, `300`, …, `900`

  time += 10;

  // Will be called every 10 milliseconds
}, 10);

deduplicate

Type: (func: DeduplicatedFunction, ...args: unknown[]) => void

Detects duplicate function calls and executes the function only once during the specified interval.

Parameters

• func — A function whose duplicate executions will be detected. The first parameter of the function should be the number of detected calls.
• ...args — A set of parameters for the function being performed.

Example

import { Performer } from 'function-performer';

const performer = new Performer({
  deduplication: { interval: 100 },
});

const func1 = (count: number, arg: number) => {
  console.log({ count, arg });
};

const func2 = (count: number, arg: object) => {
  console.log({ count, arg });
};

performer.deduplicate(func1, 1); // will be blocked
performer.deduplicate(func1, 1); // logs `{ count: 2, arg: 1 }`
performer.deduplicate(func2, { foo: { bar: 'baz' } }); // will be blocked
performer.deduplicate(func2, { foo: { bar: 'baz' } }); // will be blocked
performer.deduplicate(func2, { foo: { bar: 'baz' } }); // logs `{ count: 3, arg: { foo: { bar: 'baz' } } }`

setTimeout(() => {
  performer.deduplicate(func2, { foo: { bar: 'baz' } }); // logs `{ count: 1, arg: { foo: { bar: 'baz' } } }`
}, 1000);