doc: update napi_async_init documentation

Fixes: #33153 Change documentation to make async_resource required as opposed to optional in napi-async_init. Changes over time mean this parameter is required for proper operation of async hooks (which are still experimental). This changes the documentation to document what callers should do. We are doing this only in the doc in order to avoid a breaking change in N-API. We could create a new version of the method for which the parametrer is enforced as mandatory but we should only do that once async hooks is no longer experimental. In that case we could deprecate (but not remove this version of the method). Signed-off-by: Michael Dawson <michael_dawson@ca.ibm.com> PR-URL: #33181 Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de> Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
nodejs · Jun 7, 2020 · 033bc96ec12123838302be07c7b9162e214e6635 · 033bc96
1 parent ea3a68f
commit 033bc96ec12123838302be07c7b9162e214e6635
Showing with 6 additions and 1 deletion.

+6 −1 doc/api/n-api.md
diff --git a/doc/api/n-api.md b/doc/api/n-api.md
@@ -4649,8 +4649,13 @@ napi_status napi_async_init(napi_env env,
 ```
 
 * `[in] env`: The environment that the API is invoked under.
-* `[in] async_resource`: An optional object associated with the async work
+* `[in] async_resource`: Object associated with the async work
   that will be passed to possible `async_hooks` [`init` hooks][].
+  In order to retain ABI compatibility with previous versions,
+  passing `NULL` for `async_resource` will not result in an error, however,
+  this will result incorrect operation of async hooks for the
+  napi_async_context created. Potential issues include
+  loss of async context when using the AsyncLocalStorage API.
 * `[in] async_resource_name`: Identifier for the kind of resource
   that is being provided for diagnostic information exposed by the
   `async_hooks` API.