Error handling

When a command throws an unhandled exception, any output in its print buffer will be flushed to the screen. Then the error message accompanied by a tag stack will be output to the screen and the user will be returned to the prompt.

If an unexpected error happens inside a command that is non-recoverable, do not attempt to try/catch it unless you can improve the error message to something more useful. Generally speaking, just let the error bubble up and be handled by CommandBox for consistency and simplicity.

Controlled Errors

If there are expected situations such as a file not existing, that you know might go wrong, we wholeheartedly recommend checking for these situations and using the error() method to alert the user.

Errors returned from the error() method will not contain any stack traces, etc.

error( "I don't like your tone of voice" );

You can set a detail and an error code as well. The error code will be used as the exit code for the command.

error( "We're sorry, but happy hour ended 20 minutes ago.", "Sux 2B U", 123 );

The CFML exception that is thrown from the error() method will contain the exit code in the errorcode part of the cfcatch struct. The Exit code is also available as a system setting called exitCode.

> !git status
fatal: not a git repository (or any of the parent directories): .git
Command returned failing exit code [128]
> echo ${exitCode}
128

Verbose Errors in the Shell

When an unhandled exception happens in the shell, only the tag context is shown. You can enable full stack trace output like so:

config set verboseErrors=true