iter-tools-es/impls/async-throttle/async-throttle.js

The iterable toolbox

const {
  asyncIterableCurry
} = require('../../internal/async-iterable.js');

const {
  isPositiveInteger
} = require('../../internal/number.js');

const {
  delay
} = require('../../internal/delay.js');

async function* __asyncThrottle(source, intervalMs) {
  let waitSince = 0;

  for await (const value of source) {
    const duration = intervalMs - (Date.now() - waitSince);
    await (duration > 0 && delay(duration));
    waitSince = Date.now();
    yield value;
  }
}

exports.__asyncThrottle = __asyncThrottle;
const asyncThrottle = /*#__PURE__*/asyncIterableCurry(__asyncThrottle, {
  validateArgs(args) {
    if (!isPositiveInteger(args[1], true)) {
      throw new Error('intervalMs argument to asyncThrottle must be a number > 0');
    }
  }

});
exports.asyncThrottle = asyncThrottle;