doc: mention null special-case for napi_typeof

goto-bus-stop · Gabriel Schulhof · commit 64481c2b133f · 2020-08-02T11:57:47.000-07:00
The documentation said `napi_typeof` is similar to the `typeof` operator, but the `typeof null` detects `'object'` while `napi_typeof(a_null_value)` detects `napi_null`. PR-URL: #34577 Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: Gabriel Schulhof <gabriel.schulhof@intel.com> Reviewed-By: Luigi Pinca <luigipinca@gmail.com> Reviewed-By: David Carlier <devnexen@gmail.com>
diff --git a/doc/api/n-api.md b/doc/api/n-api.md
@@ -3168,7 +3168,12 @@ Returns `napi_ok` if the API succeeded.
 
 This API represents behavior similar to invoking the `typeof` Operator on
 the object as defined in [Section 12.5.5][] of the ECMAScript Language
-Specification. However, it has support for detecting an External value.
+Specification. However, there are some differences:
+
+1. It has support for detecting an External value.
+2. It detects `null` as a separate type, while ECMAScript `typeof` would detect
+   `object`.
+
 If `value` has a type that is invalid, an error is returned.
 
 ### napi_instanceof
