NAME

       "Test::Metrics::Any" - assert that code produces metrics via Metrics::Any

SYNOPSIS

          use Test::More;
          use Test::Metrics::Any;

          use Module::Under::Test;

          is_metrics_from(
             sub { Module::Under::Test::do_a_thing for 1 .. 5 },
             {
                things_done => 5,
                time_taken => Test::Metrics::Any::positive,
             },
             'do_a_thing reported some metrics'
          );

          done_testing;

DESCRIPTION

       This test module helps write unit tests which assert that the code under test reports
       metrics via Metrics::Any.

       Loading this module automatically sets the Metrics::Any::Adapter type to "Test".

FUNCTIONS

   is_metrics
          is_metrics( \%metrics, $name )

       Asserts that the current value of every metric named in the given hash reference is set to
       the value provided. Values can either be given as exact numbers, or by one of the match
       functions mentioned in "PREDICATES".

       Key names in the given hash should match the name format used by
       Metrics::Any::Adapter::Test. Name components are joined by underscores, and any label tags
       are appended with spaces, as "name:value".

          {
             "a_basic_metric"               => 123,
             "a_labelled_metric label:here" => 456,
          }

       This function only checks the values of metrics actually mentioned in the hash given as
       its argument. It is not a failure for more metrics to have been reported by the code under
       test than are mentioned in the hash. This helps to ensure that new metrics added in code
       do not break existing tests that weren't set up to expect them.

   is_metrics_from
          is_metrics_from( $code, \%metrics, $name )

       Asserts the value of metrics reported by running the given piece of code.

       The metrics in the test adapter are cleared, then the code is invoked, then any metrics
       are checked in the same manner as "is_metrics".

PREDICATES

       As an alternative to expecting exact values for metrics, the following test functions can
       be provided instead to assert that the metric is behaving sensibly without needing to be
       an exact value. This could be useful for example when the exact number of bytes or timing
       measures can vary between test runs or platforms.

       These predicates are not exported but must be invoked fully-qualified.

   positive
          metric => Test::Metrics::Any::positive

       Asserts that the number is greater than zero. It must not be zero.

   at_least
          metric => Test::Metrics::Any::at_least( $n )

       Asserts that the number at least that given - it can be equal or greater.

   greater_than
          metric => Test::Metrics::Any::greater_than( $n )

       Asserts that the number is greater than that given - it must not be equal.

AUTHOR

       Paul Evans <leonerd@leonerd.org.uk>