lib: runtime deprecate SlowBuffer

PR-URL: #55175
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
Reviewed-By: Robert Nagy <ronagy@icloud.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

Author: RafaelGSS

doc/api/deprecations.md

@@ -695,6 +695,9 @@ Type: End-of-Life
 
 <!-- YAML
 changes:
+ - version: REPLACEME
+ pr-url: https://github.com/nodejs/node/pull/55175
+ description: Runtime deprecation.
  - version: v6.12.0
  pr-url: https://github.com/nodejs/node/pull/10116
  description: A deprecation code has been assigned.
@@ -703,7 +706,7 @@ changes:
  description: Documentation-only deprecation.
 -->
 
-Type: Documentation-only
+Type: Runtime
 
 The [`SlowBuffer`][] class is deprecated. Please use
 [`Buffer.allocUnsafeSlow(size)`][] instead.

lib/buffer.js

@@ -88,6 +88,7 @@ const {
  kIsEncodingSymbol,
  defineLazyProperties,
  encodingsMap,
+ deprecate,
 }=require('internal/util');
 const{
  isAnyArrayBuffer,
@@ -1322,7 +1323,10 @@ function isAscii(input) {
 
 module.exports={
  Buffer,
- SlowBuffer,
+SlowBuffer: deprecate(
+SlowBuffer,
+'SlowBuffer() is deprecated. Please use Buffer.allocUnsafeSlow()',
+'DEP0030'),
  transcode,
  isUtf8,
  isAscii,

test/parallel/test-buffer-slow.js

@@ -1,12 +1,18 @@
 'use strict';
 
-require('../common');
+constcommon=require('../common');
 constassert=require('assert');
 constbuffer=require('buffer');
 constSlowBuffer=buffer.SlowBuffer;
 
 constones=[1,1,1,1];
 
+common.expectWarning(
+'DeprecationWarning',
+'SlowBuffer() is deprecated. Please use Buffer.allocUnsafeSlow()',
+'DEP0030'
+);
+
 // Should create a Buffer
 letsb=SlowBuffer(4);
 assert(sbinstanceofBuffer);