source: imaps-frontend/node_modules/is-symbol/test/index.js@ 79a0317

'use strict';

var test = require('tape');
var forEach = require('for-each');
var v = require('es-value-fixtures');

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

var hasSymbols = require('has-symbols')();
var hasToStringTag = require('has-tostringtag/shams')();
var inspect = require('object-inspect');

test('non-symbol values', function (t) {
        var nonSymbols = v.nonSymbolPrimitives.concat(
                Object(true),
                Object(false),
                // @ts-expect-error TS sucks with concat
                {},
                [],
                /a/g,
                new Date(),
                function () {},
                NaN
        );
        t.plan(nonSymbols.length);
        forEach(nonSymbols, function (nonSymbol) {
                t.equal(isSymbol(nonSymbol), false, inspect(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(isSymbol(fakeSymbol), false, 'object with valueOf returning a symbol is not a symbol');
                st.end();
        });

        t.test('faked @@toStringTag', { skip: !hasToStringTag }, function (st) {
                /** @type {{ valueOf(): unknown; [Symbol.toStringTag]?: unknown }} */
                var fakeSymbol = { valueOf: function () { return Symbol('foo'); } };
                fakeSymbol[Symbol.toStringTag] = 'Symbol';
                st.equal(isSymbol(fakeSymbol), false, 'object with fake Symbol @@toStringTag and valueOf returning a symbol is not a symbol');

                /** @type {{ valueOf(): unknown; [Symbol.toStringTag]?: unknown }} */
                var notSoFakeSymbol = { valueOf: function () { return 42; } };
                notSoFakeSymbol[Symbol.toStringTag] = 'Symbol';
                st.equal(isSymbol(notSoFakeSymbol), false, '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(isSymbol(fakeSymbolString), false, '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) {
                /** @type {(name: string) => name is Exclude<keyof SymbolConstructor, 'for' | 'keyFor'>} */
                var isWellKnown = function filterer(name) {
                        return name !== 'for' && name !== 'keyFor' && !(name in filterer);
                };
                var wellKnownSymbols = Object.getOwnPropertyNames(Symbol).filter(isWellKnown);
                wellKnownSymbols.forEach(function (name) {
                        // eslint-disable-next-line no-extra-parens
                        var sym = Symbol[/** @type {keyof SymbolConstructor} */ (name)];
                        st.equal(isSymbol(sym), true, inspect(sym) + ' is a symbol');
                });
                st.end();
        });

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

        t.end();
});