map-has-symbol.js - mozsearch

Enable keyboard shortcuts

// Return a new map, possibly filling some dummy entries to enforce creating

// multiple hash buckets.

function createMap(values, n) {

  var xs = [...values];

  for (var i = 0; i < n; ++i) {

    xs.push({});

  return new Map(xs.map((x, i) => [x, i]));

function runTest(fn) {

  fn(0);

  fn(100);

function test(n) {

  var xs = [Symbol(), Symbol()];

  var ys = [Symbol(), Symbol()];

  var zs = [...xs, ...ys];

  var map = createMap(xs, n);

  var N = 100;

  var c = 0;

  for (var i = 0; i < N; ++i) {

    var z = zs[i & 3];

    if (map.has(z)) c++;

  assertEq(c, N / 2);

runTest(test);