source: imaps-frontend/node_modules/is-symbol/test/index.js

'use strict';

var test = require('tape');
var isSymbol = require('../index');

var forEach = function (arr, func) {
        var i;
        for (i = 0; i < arr.length; ++i) {
                func(arr[i], i, arr);
        }
};

var hasSymbols = require('has-symbols')();
var inspect = require('object-inspect');
var debug = function (v, m) { return inspect(v) + ' ' + m; };

test('non-symbol values', function (t) {
        var nonSymbols = [
                true,
                false,
                Object(true),
                Object(false),
                null,
                undefined,
                {},
                [],
                /a/g,
                'string',
                42,
                new Date(),
                function () {},
                NaN
        ];
        t.plan(nonSymbols.length);
        forEach(nonSymbols, function (nonSymbol) {
                t.equal(false, isSymbol(nonSymbol), debug(nonSymbol, 'is not a symbol'));
        });
        t.end();
});

test('faked symbol values', function (t) {
        t.test('real symbol valueOf', { skip: !hasSymbols }, function (st) {
                var fakeSymbol = { valueOf: function () { return Symbol('foo'); } };
                st.equal(false, isSymbol(fakeSymbol), 'object with valueOf returning a symbol is not a symbol');
                st.end();
        });

        t.test('faked @@toStringTag', { skip: !hasSymbols || !Symbol.toStringTag }, function (st) {
                var fakeSymbol = { valueOf: function () { return Symbol('foo'); } };
                fakeSymbol[Symbol.toStringTag] = 'Symbol';
                st.equal(false, isSymbol(fakeSymbol), 'object with fake Symbol @@toStringTag and valueOf returning a symbol is not a symbol');
                var notSoFakeSymbol = { valueOf: function () { return 42; } };
                notSoFakeSymbol[Symbol.toStringTag] = 'Symbol';
                st.equal(false, isSymbol(notSoFakeSymbol), 'object with fake Symbol @@toStringTag and valueOf not returning a symbol is not a symbol');
                st.end();
        });

        var fakeSymbolString = { toString: function () { return 'Symbol(foo)'; } };
        t.equal(false, isSymbol(fakeSymbolString), 'object with toString returning Symbol(foo) is not a symbol');

        t.end();
});

test('Symbol support', { skip: !hasSymbols }, function (t) {
        t.test('well-known Symbols', function (st) {
                var isWellKnown = function filterer(name) {
                        return name !== 'for' && name !== 'keyFor' && !(name in filterer);
                };
                var wellKnownSymbols = Object.getOwnPropertyNames(Symbol).filter(isWellKnown);
                wellKnownSymbols.forEach(function (name) {
                        var sym = Symbol[name];
                        st.equal(true, isSymbol(sym), debug(sym, ' is a symbol'));
                });
                st.end();
        });

        t.test('user-created symbols', function (st) {
                var symbols = [
                        Symbol(),
                        Symbol('foo'),
                        Symbol['for']('foo'),
                        Object(Symbol('object'))
                ];
                symbols.forEach(function (sym) {
                        st.equal(true, isSymbol(sym), debug(sym, ' is a symbol'));
                });
                st.end();
        });

        t.end();
});