Devel::Cover merging coverage data for Perl scripts and modules - perl

Question

I'm having issues merging data for coverage on Perl scripts and modules.. Running Devel::Cover individually works just fine, but when I try to combine the data I lose statistics for just the Perl script not the module..
Let me explain..
I have a directory tree that looks like so..
Code_Coverage_Test
|
|---->lib
|
|---->t
|
Inside the root Code_Coverage_Test directory I have the Build.pl file that builds the tests for the module and script that kickoff two other scripts that automate some commands for me..
./Build.pl
#!/usr/bin/perl -w
use strict;
use Module::Build;
my $buildTests = Module::Build->new(
module_name => 'testPMCoverage',
license => 'perl',
dist_abstract => 'Perl .pm Test Code Coverage',
dist_author => 'me#myEmail.com',
build_requires => {
'Test::More' => '0.10',
},
);
$buildTests->create_build_script();
./startTests.sh
#!/bin/sh
cd t
./doPMtest.sh
./doPLtest.sh
cd ../
perl Build testcover
Inside the lib dir I have the files I'm trying to run Code coverage on..
lib/testPLCoverage.pl
#!/usr/bin/perl -w
use strict;
print "Ok!";
lib/testPMCoverage.pm
use strict;
use warnings;
package testPMCoverage;
sub hello {
return "Hello";
}
sub bye {
return "Bye";
}
1;
In the t dir I have my .t test file for the module and 2 scripts that kickoff the tests for me.. Both of which are called by the startTests.sh in the root directory
t/testPMCoverage.t
#!/usr/bin/perl -w
use strict;
use Test::More;
require_ok( 'testPMCoverage' );
my $test = testPMCoverage::hello();
is($test, "Hello", "hello() test");
done_testing();
t/doPLtest.sh
#!/bin/sh
#Test 1
cd ../
cd lib
perl -MDevel::Cover=-db,../cover_db testPLCoverage.pl
t/doPMtest.sh
#!/bin/bash
cd ../
perl Build.pl
perl Build test
The issue I'm running into is that when the doPLtests.sh script runs, I get coverage data, no problem..
---------------------------- ------ ------ ------ ------ ------ ------ ------
File STMT Bran Cond Sub pod Time total
---------------------------- ------ ------ ------ ------ ------ ------ ------
testPLCoverage.pl 100.0 n/a n/a 100.0 n/a 100.0 100.0
Total 100.0 n/a n/a 100.0 n/a 100.0 100.0
---------------------------- ------ ------ ------ ------ ------ ------ ------
However, when the doPMtest.sh script finishes and the startTests.sh script initiates the Build testcover command I lose that data along the way and I get these messages ...
Reading database path/Code_Coverage_Tests/cover_db
Devel::Cover: Warning: can't open testPLCoverage.pl for MD5 digest: No such file or directory
Devel::Cover: Warning: can't locate structure for statement in testPLCoverage.pl
Devel::Cover: Warning: can't locate structure for subroutine in testPLCoverage.pl
Devel::Cover: Warning: can't locate structure for time in testPLCoverage.pl
..and somehow I lose the data
---------------------------- ------ ------ ------ ------ ------ ------ ------
File STMT Bran Cond Sub pod Time total
---------------------------- ------ ------ ------ ------ ------ ------ ------
blib/lib/testPMCoverage.pm 87.5 n/a n/a 75.0 0.0 100.0 71.4
testPLCoverage.pl n/a n/a n/a n/a n/a n/a n/a
Total 87.5 n/a n/a 75.0 0.0 100.0 71.4
---------------------------- ------ ------ ------ ------ ------ ------ ------
How can I combine the Perl module and Perl script tests to get valid code coverage in ONE file?

Answer 1

Perl doesn't store the full path to the files it uses. If it finds the file via a relative path then only the relative path is stored. You can see this in the paths perl shows in the warning and error messages from those files.
When Devel::Cover deals with files it uses the path given by perl. You can see this in the reports from Devel::Cover where you have testPLCoverage.pl and blib/lib/testPMCoverage.pm.
What this means for you in practice is that whenever you put coverage into a coverage DB you should ensure that you are doing it from the same directory, so that Devel::Cover can match and locate the files in the coverage DB.
I think this is the problem you are hitting.
My suggestion is that in t/doPLtest.sh you don't cd into lib. You can run something like:
perl -Mblib -MDevel::Cover=-db,../cover_db lib/testPLCoverage.pl
(As an aside, why is that file in lib?)
I think that would mean that Devel::Cover would be running from the project root in each case and so should allow it to match and find the files.