tests/symbol.html

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<html>
<head>
  <title>Symbol Polyfill</title>
  <script id="loader" src="../webcomponents-loader.js"></script>
  <script src="./wct-config.js"></script>
  <script src="../node_modules/wct-browser-legacy/browser.js"></script>
</head>
<body>
  <script>
    suite('Symbol Polyfill', function() {
      test('Symbol exists', function() {
        assert.property(window, 'Symbol');
      });

      test('Symbol.iterator exists', function() {
        assert.property(Symbol, 'iterator');
      });

      suite('Iterators', function() {
        test('Array iterator', function(){
          const arr = [1,2,3,4];
          const out = [];
          for (const item of arr) {
            out.push(item);
          }
          assert.deepEqual(arr, out);
        });
        test('String iterator', function(){
          const str = 'hello world!';
          let out = '';
          for (const char of str) {
            out += char;
          }
          assert.equal(str, out);
        });
        test('Map iterator', function(){
          const map = new Map();
          map.set(1, 'a');
          map.set(2, 'b');
          for (const [key, value] of map) {
            assert.equal(map.get(key), value);
          }
        });
        test('Set iterator', function(){
          const set = new Set();
          set.add(1);
          set.add(2);
          set.add(3);
          for (const item of set) {
            assert(set.has(item), `set should have item ${item}`);
          }
        });
      });

      test('Object.getOwnPropertySymbols', function() {
        const s1 = Symbol('s1');
        const s2 = Symbol('s2');
        const obj = {
          a: 1,
          [s1]: 2,
          b: 3,
          [s2]: 4
        };

        assert.deepEqual(Object.getOwnPropertyNames(obj), ['a', 'b']);
        assert.deepEqual(Object.keys(obj), ['a', 'b']);
        assert.deepEqual(Object.getOwnPropertySymbols(obj), [s1, s2]);
      });

      // https://github.com/webcomponents/webcomponentsjs/issues/987
      test('Object.keys does not throw on property with undefined descriptor', function() {
        assert.doesNotThrow(() => Object.keys(window));
      });

      // https://github.com/webcomponents/webcomponentsjs/issues/1047
      test('Object.prototype.toString works correctly when called against null/undefined', function() {
        assert.equal(Object.prototype.toString.call(undefined), '[object Undefined]');
        assert.equal(Object.prototype.toString.call(null), '[object Null]');
      });

      // https://github.com/webcomponents/webcomponentsjs/issues/1047
      // Mocha's `done` calls Object.prototype.toString.call(undefined) when
      // no error is passed to `done`
      test('mocha async tests work', function(done) {
        done();
      });
    })
  </script>
</body>
</html>