fixup: benchmark

Author: ronag

benchmark/streams/transform-by.js

@@ -0,0 +1,23 @@
+'use strict';
+
+const common = require('../common');
+const Transform = require('stream').Transform;
+
+const bench = common.createBenchmark(main, {
+  n: [1e6]
+});
+
+function main({ n }) {
+  const s = Transform.by(async function*(source) {
+    for await (const chunk of source) {
+      yield chunk.toUpperCase();
+    }
+  });
+  s.resume();
+
+  bench.start();
+  for (var k = 0; k < n; ++k) {
+    s.write(String.fromCharCode(n % 64 + 64));
+  }
+  s.end(() => bench.end(n));
+}