[Israel.pm] Testing problem

[Jason Elbaum]

Thomas Maier wrote:

> sub method 
> {
> 	my ($self, at param) = @_;
> 	$pid = open $fh,"-|","command @param";
> 	$x = do something with $fh;
> 	return $x;
> }
> 
> I would like to test this method but without
> actually running the 'command'. 

I haven't thought this through to the end, but here are some preliminary 
ideas.


First, you need to separate the running of the command from the method. 
One way to do this:


sub method
{
	my ($self, $commandSubRef, @param) = @_;

         # Execute command, creating a pid and a file handle
	($pid, $fh) = $commandSubRef->(@param);

	$x = do something with $fh;
	return $x;
}

Then your production code can call the method like this:

sub command
{
  	my @param = @_;
	$pid = open $fh,"-|","command @param";
	return ($pid, $fh);
}

$self->method(command, @param);


Your test code can provide an alternative implementation of command 
which, for example, reads a predefined file. For example:

sub commandTester
{
  	my @param = @_;

	$pid = open $fh,"-|","cat testfile";
	return ($pid, $fh);
}


Is this helpful?


Jason Elbaum