[8.x] Bugfix passing errorlevel when command is run in background

[arjenvanoostrum]

On windows machines, when console commands are run in background, using
$schedule->command('inspire')->runInBackground()
an errorlevel variable is supposed to be passed to the schedule:finish command, enabling the after hooks for success/failure

However, default behaviour in the cmd.exe shell is that variables are read and expanded line-by-line.
As the background commands are started in a fresh cmd.exe instance, and contain a single-line command, the errorlevel variable is not set to the exit code of the command, and will always be the default 0.

This prevents using the onFailure... methods on the scheduled command as it will always take the succesful route.

in a fresh terminal:
cmd /c exit 2 & echo "errorlevel=%errorlevel%"
will display "errorlevel=0"

while executing this line twice in a terminal:
cmd /c exit 2 & echo "errorlevel=%errorlevel%"
cmd /c exit 4 & echo "errorlevel=%errorlevel%"
will display
"errorlevel=0"
"errorlevel=2" --> at this time the errorlevel set in the first line is used.

This behaviour can be changed by enabling delayed expansion (https://ss64.com/nt/delayedexpansion.html), however setting this with SETLOCAL would also require a newline itself.

So probably the best thing to do is using the command1 && command2 || command3 syntax (https://ss64.com/nt/syntax-redirection.html), in which case command 2 (finishing succesful with errorlevel 0) is only executed when command1 is succesfuly run, otherwise command 3 (finishing with errorlevel 1) is executed.
Note that command3 will also be executed when command 2 may fail.

[taylorotwell]

So the finished command will run twice if it fails the first time?

[arjenvanoostrum]

Yes indeed. This may be considered strange behaviour, though one may reason that the execution of the schedule should not be considered succesful when the success callbacks fail.

So when a schedule is defined as:
$schedule->command('inspire')
->hourly()
->onSuccess(function(){ $this->doSomething(); }
->onFailure(function(){ Log::error("Something went wrong"); })
->runInBackground();

When doSomething fails, it will also log "Something went wrong", which I think is useful.

[taylorotwell]

Honestly I'll need more Windows developers to look at this. I don't have a Windows development environment configured.

[taylorotwell]

I tried this out on a Windows machine and I'm not sure I want to go with this solution at the moment. If the command executes fine but then the success callback has an error then the failure callback will be called which may not be expected or wanted? Maybe there is another approach to solving this?