[js-perf-test] add microbenchmarks for String Iterators

test/js-perf-test/StringIterators/string-iterator.js

Index: test/js-perf-test/StringIterators/string-iterator.js
diff --git a/test/js-perf-test/StringIterators/string-iterator.js b/test/js-perf-test/StringIterators/string-iterator.js
new file mode 100644
index 0000000000000000000000000000000000000000..c55925415b2e0be6a1c72adce702db05cbaaa796
--- /dev/null
+++ b/test/js-perf-test/StringIterators/string-iterator.js
@@ -0,0 +1,239 @@
+// 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 assert(expression, message) {
+  if (typeof expression === "string" && message === void 0) {
+    message = expression;
+    expression = eval(expression);
+  }
+
+  if (!expression) {
+    var lines = ["Benchmark Error"];
+    if (message !== void 0) {
+      lines = ["Benchmark Error:", String(message)];
+    }
+    throw new Error(lines.join("\n"));
+  }
+  return true;
+}
+
+assert.same = function(expected, actual, message) {
+  var isSame =
+      expected === actual || typeof expected !== expected && actual !== actual;
+  if (!isSame) {
+    var details = `Expected:  ${String(expected)}\n` +
+                  `But found: ${String(actual)}`;
+    var lines = ["Benchmark Error:", details];
+    if (message !== void 0) {
+      lines = ["Benchmark Error:", details, "", String(message)];
+    }
+    throw new Error(lines.join("\n"));
+  }
+  return true;
+}
+
+new BenchmarkSuite('Spread_OneByteShort', [1000], [
+  new Benchmark('test', false, false, 0,
+                Spread_OneByteShort, Spread_OneByteShortSetup,
+                Spread_OneByteShortTearDown),
+]);
+
+var result;
+var string;
+function Spread_OneByteShortSetup() {
+  result = undefined;
+  string = "Alphabet-Soup";
+}
+
+function Spread_OneByteShort() {
+  result = [...string];
+}
+
+function Spread_OneByteShortTearDown() {
+  var expected = "A|l|p|h|a|b|e|t|-|S|o|u|p";
+  return assert("Array.isArray(result)")
+      && assert.same(expected, result.join("|"));
+}
+
+// ----------------------------------------------------------------------------
+
+new BenchmarkSuite('Spread_TwoByteShort', [1000], [
+  new Benchmark('test', false, false, 0,
+                Spread_TwoByteShort, Spread_TwoByteShortSetup,
+                Spread_TwoByteShortTearDown),
+]);
+
+function Spread_TwoByteShortSetup() {
+  result = undefined;
+  string = "\u5FCD\u8005\u306E\u653B\u6483";
+}
+
+function Spread_TwoByteShort() {
+  result = [...string];
+}
+
+function Spread_TwoByteShortTearDown() {
+  var expected = "\u5FCD|\u8005|\u306E|\u653B|\u6483";
+  return assert("Array.isArray(result)")
+      && assert.same(expected, result.join("|"));
+}
+
+// ----------------------------------------------------------------------------
+
+new BenchmarkSuite('Spread_WithSurrogatePairsShort', [1000], [
+  new Benchmark('test', false, false, 0,
+                Spread_WithSurrogatePairsShort,
+                Spread_WithSurrogatePairsShortSetup,
+                Spread_WithSurrogatePairsShortTearDown),
+]);
+
+function Spread_WithSurrogatePairsShortSetup() {
+  result = undefined;
+  string = "\uD83C\uDF1F\u5FCD\u8005\u306E\u653B\u6483\uD83C\uDF1F";
+}
+
+function Spread_WithSurrogatePairsShort() {
+  result = [...string];
+}
+
+function Spread_WithSurrogatePairsShortTearDown() {
+  var expected =
+      "\uD83C\uDF1F|\u5FCD|\u8005|\u306E|\u653B|\u6483|\uD83C\uDF1F";
+  return assert("Array.isArray(result)")
+      && assert.same(expected, result.join("|"));
+}
+
+// ----------------------------------------------------------------------------
+
+new BenchmarkSuite('ForOf_OneByteShort', [1000], [
+  new Benchmark('test', false, false, 0,
+                ForOf_OneByteShort, ForOf_OneByteShortSetup,
+                ForOf_OneByteShortTearDown),
+]);
+
+function ForOf_OneByteShortSetup() {
+  result = undefined;
+  string = "Alphabet-Soup";
+}
+
+function ForOf_OneByteShort() {
+  result = "";
+  for (var c of string) result += c;
+}
+
+function ForOf_OneByteShortTearDown() {
+  return assert.same(string, result);
+}
+
+// ----------------------------------------------------------------------------
+
+new BenchmarkSuite('ForOf_TwoByteShort', [1000], [
+  new Benchmark('test', false, false, 0,
+                ForOf_TwoByteShort, ForOf_TwoByteShortSetup,
+                ForOf_TwoByteShortTearDown),
+]);
+
+function ForOf_TwoByteShortSetup() {
+  result = undefined;
+  string = "\u5FCD\u8005\u306E\u653B\u6483";
+}
+
+function ForOf_TwoByteShort() {
+  result = "";
+  for (var c of string) result += c;
+}
+
+function ForOf_TwoByteShortTearDown() {
+  return assert.same(string, result);
+}
+
+// ----------------------------------------------------------------------------
+
+new BenchmarkSuite('ForOf_WithSurrogatePairsShort', [1000], [
+  new Benchmark('test', false, false, 0,
+                ForOf_WithSurrogatePairsShort,
+                ForOf_WithSurrogatePairsShortSetup,
+                ForOf_WithSurrogatePairsShortTearDown),
+]);
+
+function ForOf_WithSurrogatePairsShortSetup() {
+  result = undefined;
+  string = "\uD83C\uDF1F\u5FCD\u8005\u306E\u653B\u6483\uD83C\uDF1F";
+}
+
+function ForOf_WithSurrogatePairsShort() {
+  result = "";
+  for (var c of string) result += c;
+}
+
+function ForOf_WithSurrogatePairsShortTearDown() {
+  return assert.same(string, result);
+}
+
+// ----------------------------------------------------------------------------
+
+new BenchmarkSuite('ForOf_OneByteLong', [1000], [
+  new Benchmark('test', false, false, 0,
+                ForOf_OneByteLong, ForOf_OneByteLongSetup,
+                ForOf_OneByteLongTearDown),
+]);
+
+function ForOf_OneByteLongSetup() {
+  result = undefined;
+  string = "Alphabet-Soup|".repeat(128);
+}
+
+function ForOf_OneByteLong() {
+  result = "";
+  for (var c of string) result += c;
+}
+
+function ForOf_OneByteLongTearDown() {
+  return assert.same(string, result);
+}
+
+// ----------------------------------------------------------------------------
+
+new BenchmarkSuite('ForOf_TwoByteLong', [1000], [
+  new Benchmark('test', false, false, 0,
+                ForOf_OneByteLong, ForOf_OneByteLongSetup,
+                ForOf_OneByteLongTearDown),
+]);
+
+function ForOf_TwoByteLongSetup() {
+  result = undefined;
+  string = "\u5FCD\u8005\u306E\u653B\u6483".repeat(128);
+}
+
+function ForOf_TwoByteLong() {
+  result = "";
+  for (var c of string) result += c;
+}
+
+function ForOf_TwoByteLongTearDown() {
+  return assert.same(string, result);
+}
+
+// ----------------------------------------------------------------------------
+
+new BenchmarkSuite('ForOf_WithSurrogatePairsLong', [1000], [
+  new Benchmark('test', false, false, 0,
+                ForOf_WithSurrogatePairsLong, ForOf_WithSurrogatePairsLongSetup,
+                ForOf_WithSurrogatePairsLongTearDown),
+]);
+
+function ForOf_WithSurrogatePairsLongSetup() {
+  result = undefined;
+  string = "\uD83C\uDF1F\u5FCD\u8005\u306E\u653B\u6483\uD83C\uDF1F|"
+      .repeat(128);
+}
+
+function ForOf_WithSurrogatePairsLong() {
+  result = "";
+  for (var c of string) result += c;
+}
+
+function ForOf_WithSurrogatePairsLongTearDown() {
+  return assert.same(string, result);
+}