33b23529f4
- 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}
108 lines
3.4 KiB
JavaScript
108 lines
3.4 KiB
JavaScript
// Copyright 2016 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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(function TestMeta() {
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assertEquals(1, String.prototype.padStart.length);
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assertEquals("function", typeof String.prototype.padStart);
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assertEquals(Object.getPrototypeOf(Function),
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Object.getPrototypeOf(String.prototype.padStart));
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assertEquals("padStart", String.prototype.padStart.name);
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var desc = Object.getOwnPropertyDescriptor(String.prototype, "padStart");
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assertFalse(desc.enumerable);
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assertTrue(desc.configurable);
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assertTrue(desc.writable);
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assertEquals(undefined, desc.get);
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assertEquals(undefined, desc.set);
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assertThrows(() => new Function(`${String.prototype.padStart}`), SyntaxError);
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})();
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(function TestRequireObjectCoercible() {
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var padStart = String.prototype.padStart;
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assertThrows(() => padStart.call(null, 4, "test"), TypeError);
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assertThrows(() => padStart.call(undefined, 4, "test"), TypeError);
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assertEquals(" 123", padStart.call({
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__proto__: null,
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valueOf() { return 123; }
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}, 6, " "));
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var proxy = new Proxy({}, {
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get(t, name) {
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if (name === Symbol.toPrimitive || name === "toString") return;
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if (name === "valueOf") return () => 6.7;
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assertUnreachable();
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}
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});
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assertEquals(" 6.7", padStart.call(proxy, 6, " "));
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proxy = new Proxy({}, {
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get(t, name) {
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if (name === Symbol.toPrimitive || name === "valueOf") return;
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if (name === "toString") return () => 6.7;
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assertUnreachable();
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}
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});
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assertEquals(" 6.7", padStart.call(proxy, 6, " "));
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})();
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(function TestToLength() {
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assertThrows(() => "123".padStart(Symbol("16")), TypeError);
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assertEquals("123", "123".padStart(-1));
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assertEquals("123", "123".padStart({ toString() { return -1; } }));
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assertEquals("123", "123".padStart(-0));
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assertEquals("123", "123".padStart({ toString() { return -0; } }));
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assertEquals("123", "123".padStart(+0));
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assertEquals("123", "123".padStart({ toString() { return +0; } }));
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assertEquals("123", "123".padStart(NaN));
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assertEquals("123", "123".padStart({ toString() { return NaN; } }));
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})();
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(function TestFillerToString() {
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assertEquals(" .", ".".padStart(10));
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assertEquals(" .", ".".padStart(10, undefined));
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assertEquals("nullnulln.", ".".padStart(10, null));
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assertEquals("XXXXXXXXX.", ".".padStart(10, { toString() { return "X"; } }));
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assertEquals(
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"111111111.",
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".".padStart(10, { toString: undefined, valueOf() { return 1; } }));
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})();
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(function TestFillerEmptyString() {
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assertEquals(".", ".".padStart(10, ""));
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assertEquals(".", ".".padStart(10, { toString() { return ""; } }));
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assertEquals(
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".", ".".padStart(10, { toString: undefined, valueOf() { return ""; } }));
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})();
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(function TestFillerRepetition() {
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for (var i = 2000; i > 0; --i) {
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var expected = "xoxo".repeat(i / 4).slice(0, i - 3) + "123";
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var actual = "123".padStart(i, "xoxo");
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assertEquals(expected, actual);
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assertEquals(i > "123".length ? i : 3, actual.length);
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}
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})();
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(function TestTruncation() {
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assertEquals("ba", "a".padStart(2, "bc"));
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})();
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(function TestMaxLength() {
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assertThrows(() => "123".padStart(Math.pow(2, 40)), RangeError);
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assertThrows(() => "123".padStart(1 << 30), RangeError);
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})();
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(function TestNoArguments() {
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assertEquals("abc", "abc".padStart());
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})();
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