Promise deduplicate

Install

npm install promise-deduplicate

For yarn

yarn add promise-deduplicate

Examples

One key

import { PromisesDeduplicate } from 'promise-deduplicate';

// Create deduplicator instance
const deduplicate = new PromisesDeduplicate();

let counter = 0

// Asynchronous function we want to deduplicated
async function fetchData(): Promise<string> {
    // Imitation of an asynchronous request
    return new Promise((resolve) => {
        setTimeout(() => resolve(++counter), 1000);
    });
}

// Using
async function main() {
    const id = '123';

    // The first challenge - will begin execution
    const promise1 = deduplicate.handle(id, () => fetchData());

    // The second challenge with the same key - will return the same Promise
    const promise2 = deduplicate.handle(id, () => fetchData());

    // We expect the end
    const result1 = await promise1;
    const result2 = await promise2;

    console.log(result1); // 1
    console.log(result2); // 1
}

main();

Few keys

import { PromisesDeduplicate } from 'promise-deduplicate';

const deduplicate = new PromisesDeduplicate();

let counter = 0

async function fetchData(): Promise<string> {
  return new Promise((resolve) => {
    setTimeout(() => resolve(++counter), 1000);
  });
}

async function main() {
  const id1 = '123';
  const id2 = '456';

  // First call for ID1
  const promise1 = deduplicate.handle(id1, () => fetchData());

  // First call for ID2
  const promise2 = deduplicate.handle(id2, () => fetchData());

  // We expect the end
  const result1 = await promise1;
  const result2 = await promise2;

  console.log(result1); // 1
  console.log(result2); // 2
}

main();

Author

• AleksDolgop | Github

Support

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