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::Cover 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>.