Run results for: Can add to WeakSet?

Run details:

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:55.0) Gecko/20100101 Firefox/55.0

Browser: Firefox 55

Operating system: Ubuntu

Device Platform: Other

Date tested: 7 years ago

Test name	Executions per second
canBeAddedToWeakSet_switch_simple	514.9 Ops/sec
canBeAddedToWeakSet_switch_htmlallcollection	409.7 Ops/sec
canBeAddedToWeakSet_from_es6_weakset	491.0 Ops/sec
canBeAddedToWeakSet_3eq_typeof_x2	510.4 Ops/sec
canBeAddedToWeakSet_2eq_typeof_x2	423.0 Ops/sec
canBeAddedToWeakSet_implicit_typeof_x2	341.6 Ops/sec
canBeAddedToWeakSet_boolean_typeof_x2	326.7 Ops/sec

Script Preparation code:

var DATA = (function (K, N, total) {
    function random(n) {
        return Math.floor(Math.random() * 7);
    }

    function randomKey() {
        return Math.random().toString(36).slice(2);
    }

    function randomCollection(count = random(N)) {
        for (var a = new Array(count), i = 0; i < count; i++) {
            a[i] = randomValue();
        }

        return a;
    }

    function randomObject(keysCount = random(N)) {
        for (var obj = {}, i = 0; i < keysCount; i++) {
            obj[randomKey()] = randomValue();
        }

        return obj;
    }

    function randomValue(type = random(K)) {
      switch (type % K) {
        case 0: return undefined;
        case 1: return null; break;
        case 2: return String(Math.random());
        case 3: return Math.random() > 0.5;
        case 4: return Math.random() * 1E3;
        case 5: return randomCollection();
        default: return randomObject();
      }
    }

    return randomCollection(total);
}(7, 5, 1E5));

function canBeAddedToWeakSet_switch_simple(value) {
  switch (typeof value) {
    case 'undefined':
    case 'boolean':
    case 'number':
    case 'string':
    case 'symbol':
      return false;
    case 'object':
      return value !== null
    default:
      return true;
  }
}

function canBeAddedToWeakSet_switch_htmlallcollection(value) {
  switch (typeof value) {
    case 'undefined':
      return String(value) === '[object HTMLAllCollection]'
    case 'boolean':
    case 'number':
    case 'string':
    case 'symbol':
      return false
    case 'object':
      return value !== null
    default:
      return true
  }
}

function canBeAddedToWeakSet_from_es6_weakset(value) {
    return typeof value === 'object' ? value !== null : typeof value === 'function';
}

function canBeAddedToWeakSet_3eq_typeof_x2(value) {
    return value !== null && (typeof value === 'object' || typeof value === 'function');
}

function canBeAddedToWeakSet_2eq_typeof_x2(value) {
    return value != null && (typeof value === 'object' || typeof value === 'function');
}

function canBeAddedToWeakSet_implicit_typeof_x2(value) {
    return value && (typeof value === 'object' || typeof value === 'function');
}

function canBeAddedToWeakSet_boolean_typeof_x2(value) {
    return !!value && (typeof value === 'object' || typeof value === 'function');
}

const _set_ = new WeakSet();
function canBeAddedToWeakSet_try_catch(value) {
   	try { _set_.add(value); return true; }
    catch (e) { return false; }
}

function test(canAdd) {
    const count = DATA.reduce((countOfAddables, value) => (canAdd(value) ? 1 : 0) + countOfAddables, 0);
  	console.log('can add %d out of %d values in the array', count, DATA.length);
}

Tests:

canBeAddedToWeakSet_switch_simple
test(canBeAddedToWeakSet_switch_simple);
canBeAddedToWeakSet_switch_htmlallcollection
test(canBeAddedToWeakSet_switch_htmlallcollection);
canBeAddedToWeakSet_from_es6_weakset
test(canBeAddedToWeakSet_from_es6_weakset);
canBeAddedToWeakSet_3eq_typeof_x2
test(canBeAddedToWeakSet_3eq_typeof_x2);
canBeAddedToWeakSet_2eq_typeof_x2
test(canBeAddedToWeakSet_2eq_typeof_x2);
canBeAddedToWeakSet_implicit_typeof_x2
test(canBeAddedToWeakSet_implicit_typeof_x2);
canBeAddedToWeakSet_boolean_typeof_x2
test(canBeAddedToWeakSet_boolean_typeof_x2);
canBeAddedToWeakSet_try_catch
test(canBeAddedToWeakSet_try_catch);

Run results for: Can add to WeakSet?

How to check beforehand that the value won't throw exception when added to WeakSet in JavaScript? What is the most performant way?

canBeAddedToWeakSet_switch_simple

canBeAddedToWeakSet_switch_htmlallcollection

canBeAddedToWeakSet_from_es6_weakset

canBeAddedToWeakSet_3eq_typeof_x2

canBeAddedToWeakSet_2eq_typeof_x2

canBeAddedToWeakSet_implicit_typeof_x2

canBeAddedToWeakSet_boolean_typeof_x2

canBeAddedToWeakSet_try_catch