Frontend/25_01_07/mai/node_modules/is-symbol/test/index.js

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2025-01-28 10:38:27 +00:00
'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();
});