benchmarks: add microbenchmarks for new ES6 features

Adds new microbenchmarks for destructuring, rest params and
default params.

PR-URL: https://github.com/nodejs/node/pull/6222
Reviewed-By: Brian White <mscdex@mscdex.net>

1 files changed, 50 insertions, 0 deletions

diff --git a/benchmark/es/destructuring-bench.js b/benchmark/es/destructuring-bench.js
new file mode 100644
index 0000000000..0e9b5e93f3
--- /dev/null
+++ b/benchmark/es/destructuring-bench.js
@@ -0,0 +1,50 @@
+'use strict';
+
+const common = require('../common.js');
+const assert = require('assert');
+
+const bench = common.createBenchmark(main, {
+  method: ['swap', 'destructure'],
+  millions: [100]
+});
+
+function runSwapManual(n) {
+  var i = 0, x, y, r;
+  bench.start();
+  for (; i < n; i++) {
+    x = 1, y = 2;
+    r = x;
+    x = y;
+    y = r;
+    assert.strictEqual(x, 2);
+    assert.strictEqual(y, 1);
+  }
+  bench.end(n / 1e6);
+}
+
+function runSwapDestructured(n) {
+  var i = 0, x, y;
+  bench.start();
+  for (; i < n; i++) {
+    x = 1, y = 2;
+    [x, y] = [y, x];
+    assert.strictEqual(x, 2);
+    assert.strictEqual(y, 1);
+  }
+  bench.end(n / 1e6);
+}
+
+function main(conf) {
+  const n = +conf.millions * 1e6;
+
+  switch (conf.method) {
+    case 'swap':
+      runSwapManual(n);
+      break;
+    case 'destructure':
+      runSwapDestructured(n);
+      break;
+    default:
+      throw new Error('Unexpected method');
+  }
+}