buffer: consistent error for length > kMaxLength

- Always return the same error message(hopefully more informative)
  for buffer length > kMaxLength and avoid getting into V8 C++ land
  for unnecessary checks.
- Use accurate RegExp(reusable as `common.bufferMaxSizeMsg`)
  in tests for this error.
- Separate related tests from test-buffer-alloc.

PR-URL: https://github.com/nodejs/node/pull/10152
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/lib/buffer.js b/lib/buffer.js
index 557ac867e2..9a515e3381 100644
--- a/lib/buffer.js
+++ b/lib/buffer.js
@@ -115,6 +115,9 @@ function assertSize(size) {
     err = new TypeError('"size" argument must be a number');
   else if (size < 0)
     err = new RangeError('"size" argument must not be negative');
+  else if (size > binding.kMaxLength)
+    err = new RangeError('"size" argument must not be larger ' +
+                         'than ' + binding.kMaxLength);
 
   if (err) {
     // The following hides the 'assertSize' method from the
@@ -167,6 +170,7 @@ Buffer.allocUnsafeSlow = function(size) {
 function SlowBuffer(length) {
   if (+length != length)
     length = 0;
+  assertSize(+length);
   return createUnsafeBuffer(+length);
 }