node/test/simple/test-timers-ordering.js

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var common = require('../common');
var assert = require('assert');
var i;

var N = 30;

var last_i = 0;
var last_ts = 0;
var start = Date.now();

var f = function(i) {
  if (i <= N) {
    // check order
    assert.equal(i, last_i + 1, 'order is broken: ' + i + ' != ' + last_i + ' + 1');
    last_i = i;

    // check that this iteration is fired at least 1ms later than the previous
    var now = Date.now();
    console.log(i, now);
    assert(now >= last_ts + 1, 'current ts ' + now + ' < prev ts ' + last_ts + ' + 1');
    last_ts = now;

    // schedule next iteration
    setTimeout(f, 1, i + 1);
  }
};
f(1);