lib: always show ERR_INVALID_ARG_TYPE received part

This makes a effort to make sure all of these errors will actually
also show the received input.
On top of that it refactors a few tests for better maintainability.
It will also change the returned type to always be a simple typeof
instead of special handling null.

PR-URL: https://github.com/nodejs/node/pull/19445
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/string_decoder.js b/lib/string_decoder.js
index a6ae64c062..b32249ad9e 100644
--- a/lib/string_decoder.js
+++ b/lib/string_decoder.js
@@ -73,7 +73,8 @@ StringDecoder.prototype.write = function write(buf) {
     return buf;
   if (!ArrayBuffer.isView(buf))
     throw new ERR_INVALID_ARG_TYPE('buf',
-                                   ['Buffer', 'Uint8Array', 'ArrayBufferView']);
+                                   ['Buffer', 'Uint8Array', 'ArrayBufferView'],
+                                   buf);
   return decode(this[kNativeDecoder], buf);
 };