buffer: do not emit deprecation notice on Buffer.of

PR-URL: #19682
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

lib/buffer.js

@@ -236,6 +236,20 @@ Buffer.from = function from(value, encodingOrOffset, length) {
   );
 };
 
+// Identical to the built-in %TypedArray%.of(), but avoids using the deprecated
+// Buffer() constructor. Must use arrow function syntax to avoid automatically
+// adding a `prototype` property and making the function a constructor.
+//
+// Refs: https://tc39.github.io/ecma262/#sec-%typedarray%.of
+// Refs: https://esdiscuss.org/topic/isconstructor#content-11
+const of = (...items) => {
+  const newObj = createUnsafeBuffer(items.length);
+  for (var k = 0; k < items.length; k++)
+    newObj[k] = items[k];
+  return newObj;
+};
+Buffer.of = of;
+
 Object.setPrototypeOf(Buffer, Uint8Array);
 
 // The 'assertSize' method will remove itself from the callstack when an error

test/parallel/test-buffer-of-no-deprecation.js

@@ -0,0 +1,8 @@
+// Flags: --pending-deprecation --no-warnings
+'use strict';
+
+const common = require('../common');
+
+process.on('warning', common.mustNotCall());
+
+Buffer.of(0, 1);