From f52c92134c28ff5758d1bda41efb826169daa5ad Mon Sep 17 00:00:00 2001
From: Bradley Farias <bradley.meck@gmail.com>
Date: Fri, 2 Apr 2021 14:26:01 -0500
Subject: [PATCH] doc: internal/test/binding for testing

PR-URL: https://github.com/nodejs/node/pull/38026
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
---
 doc/guides/writing-tests.md | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/doc/guides/writing-tests.md b/doc/guides/writing-tests.md
index 1a23d8f2a4a0ca..8424f744d16927 100644
--- a/doc/guides/writing-tests.md
+++ b/doc/guides/writing-tests.md
@@ -286,6 +286,15 @@ const assert = require('assert');
 const freelist = require('internal/freelist');
 ```
 
+In specific scenarios it may be useful to get a hold of `primordials` or
+`internalBinding()`. You can do so using
+
+```console
+node --expose-internals -r internal/test/binding lib/fs.js
+```
+
+This only works if you preload `internal/test/binding` by command line flag.
+
 ### Assertions
 
 When writing assertions, prefer the strict versions: