Class vs Factory

class.js

class ConsecutiveFailure {
  constructor({ 
    count = 0,
    threshold = 10,
    logger = console.log,
  }) {
    this.count = count;
    this.threshold = threshold;
    this.logger = logger;
  }
  reset() {
    this.count = 0;
  }
  increment() {
    this.count += 1;
  }
  isOverThreshold() {
    return this.count > this.threshold;
  }
  async report() {
    this.increment();
    if (this.isOverThreshold()) {
      await exit(
        debug,
        'Too many consecutive failures while trying to sync new changes',
        { threshold: this.threshold }
      );
    }
  }
}

const consecutiveFailure = new ConsecutiveFailure({ threshold: 10 });
consecutiveFailure.increment(); // { count: 1 ...}
consecutiveFailure.increment(); // { count: 2 ...}
consecutiveFailure.reset(); // { count: 0 ...}

factory.js

const ConsecutiveFailure = ({
  count = 0,
  threshold = 10,
  logger = console.log,
} = {}) => ({
  count,
  threshold,
  logger,
  reset() {
    this.count = 0;
    return this;
  },
  increment() {
    this.count += 1;
    return this;
  },
  isUnderThreshold() {
    return this.count <= this.threshold;
  },
  report() {
    this.increment();
    if (this.isUnderThreshold()) {
      return Promise.resolve(this);
    }
    return exit(
      this.logger,
      'Too many consecutive failures while trying to sync new changes',
      { threshold: this.threshold }
    );
  },
});

const consecutiveFailure = ConsecutiveFailure({ threshold: 10 });
consecutiveFailure.increment(); // { count: 1 ...}
consecutiveFailure.increment(); // { count: 2 ...}
consecutiveFailure.reset(); // { count: 0 ...}

resources.md

• https://medium.com/javascript-scene/javascript-factory-functions-with-es6-4d224591a8b1
• https://medium.com/@pyrolistical/factory-functions-pattern-in-depth-356d14801c91