diff options
| author | Michael Dawson <mdawson@devrus.com> | 2021-10-14 17:28:38 +0300 |
|---|---|---|
| committer | Michael Dawson <mdawson@devrus.com> | 2021-10-20 23:01:50 +0300 |
| commit | f27f8d256e1370cb464764f3369b74200c798839 (patch) | |
| tree | e43e2c87105aa084e2739455598030249a8dd890 /doc/api/n-api.md | |
| parent | 516cdcd8aaf4c693711d3359bcd45e0dac568b0c (diff) | |
doc: clarify behavior of napi_extended_error_info
Fix up example and make it more explicit on how
you need to use napi_extended_error_info in order to
help people avoid what might be a common mistake that
we made in node-addon-api.
Refs: https://github.com/nodejs/node-addon-api/issues/1089
Signed-off-by: Michael Dawson <mdawson@devrus.com>
PR-URL: https://github.com/nodejs/node/pull/40458
Reviewed-By: Gabriel Schulhof <gabrielschulhof@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Diffstat (limited to 'doc/api/n-api.md')
| -rw-r--r-- | doc/api/n-api.md | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/doc/api/n-api.md b/doc/api/n-api.md index 7bddf9a7df8..0c0b9110947 100644 --- a/doc/api/n-api.md +++ b/doc/api/n-api.md @@ -403,12 +403,13 @@ napi_value create_addon(napi_env env); if (status != napi_ok) { \ const napi_extended_error_info* error_info = NULL; \ napi_get_last_error_info((env), &error_info); \ + const char* err_message = error_info->error_message; \ bool is_pending; \ napi_is_exception_pending((env), &is_pending); \ if (!is_pending) { \ - const char* message = (error_info->error_message == NULL) \ + const char* message = (err_message == NULL) \ ? "empty error message" \ - : error_info->error_message; \ + : err_message; \ napi_throw_error((env), NULL, message); \ return NULL; \ } \ @@ -1005,7 +1006,12 @@ This API retrieves a `napi_extended_error_info` structure with information about the last error that occurred. The content of the `napi_extended_error_info` returned is only valid up until -a Node-API function is called on the same `env`. +a Node-API function is called on the same `env`. This includes a call to +`napi_is_exception_pending` so it may often be necessary to make a copy +of the information so that it can be used later. The pointer returned +in error_message points to a statically defined string so it is safe to use +that pointer if you have copied it out of the error_message field (which will +be overwritten) before another Node-API function was called. Do not rely on the content or format of any of the extended information as it is not subject to SemVer and may change at any time. It is intended only for |