/
esnext.string.at.js
97 lines (96 loc) · 4.15 KB
/
esnext.string.at.js
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import { STRICT } from '../helpers/constants';
QUnit.test('String#at', assert => {
const { at } = String.prototype;
assert.isFunction(at);
assert.arity(at, 1);
assert.name(at, 'at');
assert.looksNative(at);
assert.nonEnumerable(String.prototype, 'at');
// String that starts with a BMP symbol
// assert.same('abc\uD834\uDF06def'.at(-Infinity), '');
// assert.same('abc\uD834\uDF06def'.at(-1), '');
assert.same('abc\uD834\uDF06def'.at(-0), 'a');
assert.same('abc\uD834\uDF06def'.at(+0), 'a');
assert.same('abc\uD834\uDF06def'.at(1), 'b');
assert.same('abc\uD834\uDF06def'.at(3), '\uD834\uDF06');
assert.same('abc\uD834\uDF06def'.at(4), '\uDF06');
assert.same('abc\uD834\uDF06def'.at(5), 'd');
// assert.same('abc\uD834\uDF06def'.at(42), '');
// assert.same('abc\uD834\uDF06def'.at(Infinity), '');
assert.same('abc\uD834\uDF06def'.at(null), 'a');
assert.same('abc\uD834\uDF06def'.at(undefined), 'a');
assert.same('abc\uD834\uDF06def'.at(), 'a');
assert.same('abc\uD834\uDF06def'.at(false), 'a');
assert.same('abc\uD834\uDF06def'.at(NaN), 'a');
assert.same('abc\uD834\uDF06def'.at(''), 'a');
assert.same('abc\uD834\uDF06def'.at('_'), 'a');
assert.same('abc\uD834\uDF06def'.at('1'), 'b');
assert.same('abc\uD834\uDF06def'.at([]), 'a');
assert.same('abc\uD834\uDF06def'.at({}), 'a');
assert.same('abc\uD834\uDF06def'.at(-0.9), 'a');
assert.same('abc\uD834\uDF06def'.at(1.9), 'b');
assert.same('abc\uD834\uDF06def'.at(7.9), 'f');
// assert.same('abc\uD834\uDF06def'.at(2 ** 32), '');
// String that starts with an astral symbol
// assert.same('\uD834\uDF06def'.at(-Infinity), '');
// assert.same('\uD834\uDF06def'.at(-1), '');
assert.same('\uD834\uDF06def'.at(-0), '\uD834\uDF06');
assert.same('\uD834\uDF06def'.at(0), '\uD834\uDF06');
assert.same('\uD834\uDF06def'.at(1), '\uDF06');
assert.same('\uD834\uDF06def'.at(2), 'd');
assert.same('\uD834\uDF06def'.at(3), 'e');
assert.same('\uD834\uDF06def'.at(4), 'f');
// assert.same('\uD834\uDF06def'.at(42), '');
// assert.same('\uD834\uDF06def'.at(Infinity), '');
assert.same('\uD834\uDF06def'.at(null), '\uD834\uDF06');
assert.same('\uD834\uDF06def'.at(undefined), '\uD834\uDF06');
assert.same('\uD834\uDF06def'.at(), '\uD834\uDF06');
assert.same('\uD834\uDF06def'.at(false), '\uD834\uDF06');
assert.same('\uD834\uDF06def'.at(NaN), '\uD834\uDF06');
assert.same('\uD834\uDF06def'.at(''), '\uD834\uDF06');
assert.same('\uD834\uDF06def'.at('_'), '\uD834\uDF06');
assert.same('\uD834\uDF06def'.at('1'), '\uDF06');
// Lone high surrogates
// assert.same('\uD834abc'.at(-Infinity), '');
// assert.same('\uD834abc'.at(-1), '');
assert.same('\uD834abc'.at(-0), '\uD834');
assert.same('\uD834abc'.at(0), '\uD834');
assert.same('\uD834abc'.at(1), 'a');
// assert.same('\uD834abc'.at(42), '');
// assert.same('\uD834abc'.at(Infinity), '');
assert.same('\uD834abc'.at(null), '\uD834');
assert.same('\uD834abc'.at(undefined), '\uD834');
assert.same('\uD834abc'.at(), '\uD834');
assert.same('\uD834abc'.at(false), '\uD834');
assert.same('\uD834abc'.at(NaN), '\uD834');
assert.same('\uD834abc'.at(''), '\uD834');
assert.same('\uD834abc'.at('_'), '\uD834');
assert.same('\uD834abc'.at('1'), 'a');
// Lone low surrogates
// assert.same('\uDF06abc'.at(-Infinity), '');
// assert.same('\uDF06abc'.at(-1), '');
assert.same('\uDF06abc'.at(-0), '\uDF06');
assert.same('\uDF06abc'.at(0), '\uDF06');
assert.same('\uDF06abc'.at(1), 'a');
// assert.same('\uDF06abc'.at(42), '');
// assert.same('\uDF06abc'.at(Infinity), '');
assert.same('\uDF06abc'.at(null), '\uDF06');
assert.same('\uDF06abc'.at(undefined), '\uDF06');
assert.same('\uDF06abc'.at(), '\uDF06');
assert.same('\uDF06abc'.at(false), '\uDF06');
assert.same('\uDF06abc'.at(NaN), '\uDF06');
assert.same('\uDF06abc'.at(''), '\uDF06');
assert.same('\uDF06abc'.at('_'), '\uDF06');
assert.same('\uDF06abc'.at('1'), 'a');
assert.same(at.call(42, 0), '4');
assert.same(at.call(42, 1), '2');
assert.same(at.call({
toString() {
return 'abc';
},
}, 2), 'c');
if (STRICT) {
assert.throws(() => at.call(null, 0), TypeError);
assert.throws(() => at.call(undefined, 0), TypeError);
}
});