n-api: change napi_callback to return napi_value

Change `napi_callback` to return `napi_value` directly instead of
requiring `napi_set_return_value`.

When we invoke the callback, we will check the return value and
call `SetReturnValue` ourselves. If the callback returns `NULL`,
we don't set the return value in v8 which would have the same
effect as previously if the callback didn't call
`napi_set_return_value`. Seems to be a more natural way
to handle return values from callbacks. As a consequence,
remove `napi_set_return_value`.

Add a `napi_value` to `napi_property_descriptor` to support string
values which couldn't be passed in the `utf8name` parameter or
symbols as property names. Class names, however, cannot be symbols
so this `napi_value` must be a string type in that case.

Remove all of the `napi_callback_info` helpers except for
`napi_get_cb_info` and make all the parameters to
`napi_get_cb_info` optional except for argc.

Update all the test collateral according to these changes.
Also add `test/addons-napi/common.h` to house some common macros
for wrapping N-API calls and error handling.

PR-URL: https://github.com/nodejs/node/pull/12248
Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

1 files changed, 5 insertions, 2 deletions

diff --git a/src/node_api_types.h b/src/node_api_types.h
index f3f3faaa64..f439cce1f9 100644
--- a/src/node_api_types.h
+++ b/src/node_api_types.h
@@ -17,8 +17,8 @@ typedef struct napi_handle_scope__ *napi_handle_scope;
 typedef struct napi_escapable_handle_scope__ *napi_escapable_handle_scope;
 typedef struct napi_callback_info__ *napi_callback_info;
 
-typedef void (*napi_callback)(napi_env env,
-                              napi_callback_info info);
+typedef napi_value (*napi_callback)(napi_env env,
+                                    napi_callback_info info);
 typedef void (*napi_finalize)(napi_env env,
                               void* finalize_data,
                               void* finalize_hint);
@@ -35,7 +35,9 @@ typedef enum {
 } napi_property_attributes;
 
 typedef struct {
+  // One of utf8name or name should be NULL.
   const char* utf8name;
+  napi_value name;
 
   napi_callback method;
   napi_callback getter;
@@ -76,6 +78,7 @@ typedef enum {
   napi_invalid_arg,
   napi_object_expected,
   napi_string_expected,
+  napi_name_expected,
   napi_function_expected,
   napi_number_expected,
   napi_boolean_expected,