MooseX::App::Plugin::Depends3pm

In your base class:

 package MyApp;
 use MooseX::App qw(Depends);
 
 use Moose::Util::TypeConstraints;
 option 'FileFormat' => (
   is  => 'ro',
   isa => enum( [qw(tsv csv xml)] ),
 );
 option 'WriteToFile' => (
   is       => 'ro',
   isa      => 'Bool',
   depends => [qw(FileFormat)],
 );

In your script:

 #!/usr/bin/env perl
 use strict;
 use warnings;
 use MyApp;
 MyApp->new_with_options( WriteToFile => 1 );
 # generates Error
 # Option 'WriteToFile' requires 'FileFormat' to be defined
 MyApp->new_with_options( WriteToFile => 1, FileFormat => 'tsv );
 # generates no errors
 MyApp->new_with_options();
 # generates no errors