doc: Add example of null to assert.ifError

Leko · BridgeAR · commit 08ada72cc692 · 2018-01-21T02:32:45.000+01:00
PR-URL: #18236 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de> Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Michaël Zasso <targos@protonmail.com>
diff --git a/doc/api/assert.md b/doc/api/assert.md
@@ -442,6 +442,8 @@ argument in callbacks.
 ```js
 const assert = require('assert').strict;
 
+assert.ifError(null);
+// OK
 assert.ifError(0);
 // OK
 assert.ifError(1);
