NAME
   Devel::Cover - Code coverage metrics for Perl

SYNOPSIS
   To get coverage for an uninstalled module:

    cover -test

   or

    cover -delete
    HARNESS_PERL_SWITCHES=-MDevel::Cover make test
    cover

   To get coverage for an uninstalled module which uses Module::Build (0.26
   or later):

    ./Build testcover

   If the module does not use the t/*.t framework:

    PERL5OPT=-MDevel::Cover make test

   If you want to get coverage for a program:

    perl -MDevel::Cover yourprog args
    cover

    perl -MDevel::Cover=-db,cover_db,-coverage,statement,time yourprog args

DESCRIPTION
   This module provides code coverage metrics for Perl.  Code coverage
   metrics describe how thoroughly tests exercise code.  By using
   Devel::Cover you can discover areas of code not exercised by your tests
   and determine which tests to create to increase coverage.  Code coverage
   can be considered as an indirect measure of quality.

   Although it is still being developed, Devel::Cover is now quite stable
   and provides many of the features to be expected in a useful coverage
   tool.

   Statement, branch, condition, subroutine, and pod coverage information
   is reported.  Statement coverage data should be reasonable.  Branch and
   condition coverage data should be mostly accurate too, although not
   always what one might initially expect.  Subroutine coverage should be
   as accurate as statement coverage.  Pod coverage comes from
   Pod::Coverage.  If Pod::Coverage::CountParents is available it will be
   used instead.  Coverage data for other criteria are not yet collected.

   The cover program can be used to generate coverage reports.
   Devel::Cover ships with a number of different reports including various
   types of HTML output, textual reports, a report to display missing
   coverage in the same format as compilation errors and a report to
   display coverage information within the Vim editor.

   It is possible to add annotations to reports, for example you could add
   a column to an HTML report showing who last changed a line, as
   determined by git blame.  Some annotation modules are shipped with
   Devel::Cover and you can easily create your own.

   The gcov2perl program can be used to convert gcov files to
   "Devel::Cover" databases.  This allows you to display your C or XS code
   coverage together with your Perl coverage, or to use any of the
   Devel::Cvoer reports to display your C coverage data.

   You may find that the coverage results don't match your expectations.
   This could be due to a bug in Devel::Cover, but code coverage can be
   unintuitive to newcomers, and especially so with Perl, so you may want
   to reconsider your expectations as well.

   Code coverage data are collected by replacing perl ops with functions
   which count how many times the ops are executed.  These data are then
   mapped back to reality using the B compiler modules.  There is also a
   statement profiling facility which should not be relied on.  For proper
   profiling use Devel::NYTProf.  Previous versions of Devel::Cover
   collected coverage data by replacing perl's runops function.  It is
   still possible to switch to that mode of operation, but this now gets
   little testing and will probably be removed soon.  You probably don't
   care about any of this.

   The most appropriate mailing list on which to discuss this module would
   be perl-qa.  Discussion has migrated there from perl-qa-metrics which is
   now defunct.  See <http://lists.perl.org/list/perl-qa.html>.

   The Devel::Cover repository can be found at
   <http://github.com/pjcj/Devel--Cover>.