process: fix process.exitCode handling for fatalException

* set process.exitCode before calling 'exit' handlers so that there will
  not be a situation where process.exitCode !== code in 'exit' callback
  during uncaughtException handling
* don't ignore process.exitCode set in 'exit' callback when failed with
  uncaughtException and there is no uncaughtException listener

PR-URL: https://github.com/nodejs/node/pull/21739
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

1 files changed, 6 insertions, 2 deletions

diff --git a/doc/api/process.md b/doc/api/process.md
index edf01258c3..df544e7f0f 100644
--- a/doc/api/process.md
+++ b/doc/api/process.md
@@ -151,9 +151,13 @@ added: v0.1.18
 
 The `'uncaughtException'` event is emitted when an uncaught JavaScript
 exception bubbles all the way back to the event loop. By default, Node.js
-handles such exceptions by printing the stack trace to `stderr` and exiting.
+handles such exceptions by printing the stack trace to `stderr` and exiting
+with code 1, overriding any previously set [`process.exitCode`][].
 Adding a handler for the `'uncaughtException'` event overrides this default
-behavior.
+behavior. You may also change the [`process.exitCode`][] in
+`'uncaughtException'` handler which will result in process exiting with
+provided exit code, otherwise in the presence of such handler the process will
+exit with 0.
 
 The listener function is called with the `Error` object passed as the only
 argument.