@diegodeg58/cyclic.sh-dynamodb/dist/cy_db_utils.js

SDK for interacting with Cyclic.sh (https://cyclic.sh) app AWS DynamoDB databases

const sleep = ms =>
  new Promise(resolve => setTimeout(resolve, ms));

const delay = retryCount =>
  new Promise(resolve => setTimeout(resolve, (2 ** retryCount) * (10 + 100 * Math.random())));

const RETRY_CODES = [
  'ResourceConflictException' // can happen with lambda => ResourceConflictException: The operation cannot be performed at this time. An update is in progress for resource:
]

const with_backoff = async (apiCall, retryCount = 0, lastError = null) => {
  if (retryCount > 5) throw new Error(lastError);
  try {
    let res = await apiCall();
    return res
  } catch (e) {
    if (e.retryable || RETRY_CODES.includes(e.code)) {
      console.log(`retry ${retryCount}: ${apiCall}`, e.toString())
      await delay(retryCount);
      return await with_backoff(apiCall, retryCount + 1, e);
    } else {
      console.log('not retryable:', e.toString())
      throw e
    }
  }
};

class RetryableError extends Error {
  constructor(message) {
    super(message);
    this.retryable = true;
  }
}

class ValidationError extends Error {
  constructor(message) {
    super(message)
    this.name = this.constructor.name
    Error.captureStackTrace(this, this.constructor);
    this.stack = this.stack.split('\n').filter((l, i) => { return !l.includes('cy_db') && i != 2 }).join("\n")
  }
}

const validate_strings = function (s, param_name) {
  if (typeof (s) !== 'string') {
    throw new ValidationError(`${param_name} must be a string value, received: ${s}`)
  }
  if (s.includes('#')) {
    throw new ValidationError(`${param_name} must not contain # character, received: ${s}`)
  }
  return true
}

module.exports = {
  with_backoff,
  RetryableError,
  ValidationError,
  validate_strings,
  delay,
  sleep
}