doc: demonstrate dangers of buffer.slice()

shalvah · BethGriggs · commit 174155dee65c · 2022-01-24T17:35:52.000Z
PR-URL: #41628 Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com> Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com> Reviewed-By: Evan Lucas <evanlucas@me.com> Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com> Reviewed-By: Mestery <mestery@protonmail.com> Reviewed-By: Rich Trott <rtrott@gmail.com>
diff --git a/doc/api/buffer.md b/doc/api/buffer.md
@@ -3425,6 +3425,14 @@ console.log(copiedBuf.toString());
 
 console.log(buf.toString());
 // Prints: buffer
+
+// With buf.slice(), the original buffer is modified.
+const notReallyCopiedBuf = buf.slice();
+notReallyCopiedBuf[0]++;
+console.log(notReallyCopiedBuf.toString());
+// Prints: cuffer
+console.log(buf.toString());
+// Also prints: cuffer (!)
 ```
 
 ```cjs
@@ -3439,6 +3447,14 @@ console.log(copiedBuf.toString());
 
 console.log(buf.toString());
 // Prints: buffer
+
+// With buf.slice(), the original buffer is modified.
+const notReallyCopiedBuf = buf.slice();
+notReallyCopiedBuf[0]++;
+console.log(notReallyCopiedBuf.toString());
+// Prints: cuffer
+console.log(buf.toString());
+// Also prints: cuffer (!)
 ```
 
 ### `buf.swap16()`
