v8/test/mjsunit/harmony/harmony-string-pad-end.js
peterwmwong 33b23529f4 [builtins] Port String.prototype.{padStart, padEnd} to CSA
- Extract core StringPrototypeRepeat code into a TFS builtin (StringRepeat)
  - Assumes arguments are a string and smi (no range checks)
- Add StringPrototypePadStart and StringPrototypePadEnd TFJ builtins
  - Added StringPadAssembler to ensure common behavior
- Removed functionality from string.js

A quick benchmark shows significant performance gains for unoptimized
code (2.1x to 2.46x) and optimized code (1.03x - 1.56x).

https: //github.com/peterwmwong/v8-perf/blob/master/string-pad/README.md
Bug: v8:5049
Change-Id: I6e4fe99fb62a3edb3d6906fd4f78b3576b5b0d13
Reviewed-on: https://chromium-review.googlesource.com/720067
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48595}
2017-10-16 14:19:19 +00:00

108 lines
3.3 KiB
JavaScript

// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
(function TestMeta() {
assertEquals(1, String.prototype.padEnd.length);
assertEquals("function", typeof String.prototype.padEnd);
assertEquals(Object.getPrototypeOf(Function),
Object.getPrototypeOf(String.prototype.padEnd));
assertEquals("padEnd", String.prototype.padEnd.name);
var desc = Object.getOwnPropertyDescriptor(String.prototype, "padEnd");
assertFalse(desc.enumerable);
assertTrue(desc.configurable);
assertTrue(desc.writable);
assertEquals(undefined, desc.get);
assertEquals(undefined, desc.set);
assertThrows(() => new Function(`${String.prototype.padEnd}`), SyntaxError);
})();
(function TestRequireObjectCoercible() {
var padEnd = String.prototype.padEnd;
assertThrows(() => padEnd.call(null, 4, "test"), TypeError);
assertThrows(() => padEnd.call(undefined, 4, "test"), TypeError);
assertEquals("123 ", padEnd.call({
__proto__: null,
valueOf() { return 123; }
}, 6, " "));
var proxy = new Proxy({}, {
get(t, name) {
if (name === Symbol.toPrimitive || name === "toString") return;
if (name === "valueOf") return () => 6.7;
assertUnreachable();
}
});
assertEquals("6.7 ", padEnd.call(proxy, 6, " "));
proxy = new Proxy({}, {
get(t, name) {
if (name === Symbol.toPrimitive || name === "valueOf") return;
if (name === "toString") return () => 6.7;
assertUnreachable();
}
});
assertEquals("6.7 ", padEnd.call(proxy, 6, " "));
})();
(function TestToLength() {
assertThrows(() => "123".padEnd(Symbol("16")), TypeError);
assertEquals("123", "123".padEnd(-1));
assertEquals("123", "123".padEnd({ toString() { return -1; } }));
assertEquals("123", "123".padEnd(-0));
assertEquals("123", "123".padEnd({ toString() { return -0; } }));
assertEquals("123", "123".padEnd(+0));
assertEquals("123", "123".padEnd({ toString() { return +0; } }));
assertEquals("123", "123".padEnd(NaN));
assertEquals("123", "123".padEnd({ toString() { return NaN; } }));
})();
(function TestFillerToString() {
assertEquals(". ", ".".padEnd(10));
assertEquals(". ", ".".padEnd(10, undefined));
assertEquals(".nullnulln", ".".padEnd(10, null));
assertEquals(".XXXXXXXXX", ".".padEnd(10, { toString() { return "X"; } }));
assertEquals(
".111111111",
".".padEnd(10, { toString: undefined, valueOf() { return 1; } }));
})();
(function TestFillerEmptyString() {
assertEquals(".", ".".padEnd(10, ""));
assertEquals(".", ".".padEnd(10, { toString() { return ""; } }));
assertEquals(
".", ".".padEnd(10, { toString: undefined, valueOf() { return ""; } }));
})();
(function TestFillerRepetition() {
for (var i = 2000; i > 0; --i) {
var expected = "123" + "xoxo".repeat(i / 4).slice(0, i - 3);
var actual = "123".padEnd(i, "xoxo");
assertEquals(expected, actual);
assertEquals(i > "123".length ? i : 3, actual.length);
}
})();
(function TestTruncation() {
assertEquals("ab", "a".padEnd(2, "bc"));
})();
(function TestMaxLength() {
assertThrows(() => "123".padEnd(Math.pow(2, 40)), RangeError);
assertThrows(() => "123".padEnd(1 << 30), RangeError);
})();
(function TestNoArguments() {
assertEquals("abc", "abc".padEnd());
})();