Test::Inline

An lightweight Raku module allowing tests anywhere in modules (thus potentially enabling access to implementation details).

This module was inspired by an r/rakulang post by codesections, who expressed a desire to have test files be more closely connected with their associated modules. While this technique doesn't remove the code from distribution versions, it does allow for testing inside of modules/classes/etc.

To use, simply add the trait is test to a Sub anywhere in your code. There is really only a single restriction

• The Sub must take no arguments(Use dynamic variables to pass data if you need to)

Here is a somewhat contrived example that should show nicely how it can be integrated.

unit module Rectangle;

use Test::Inline;

has Point $.a; # bottom left
has Point $.b; # top right

sub calculate-area($x, $y) {     $x * $y }
sub distance(      $a, $b) { abs $a - $b }

method area {
  calculate-area
    distance($!a.x, $!b.x),
    distance($!a.y, $!b.y)
}

method overlap(Rectangle $other) { ... }


sub t-distance is test {
  use Test;
  is distance( 2,4), 2;
  is distance(-2,4), 6;
  ...
}

sub t-area is test {
  use Test;
  is calculate-area(1,3),  3;
  is calculate-area(8,3), 24;
  ...
}

This marks t-area and t-distance as special subs that contains tests. Because they are inside of Rectangle, they can access its lexically scoped subs or variables, which a normal test file cannot. Each test sub can contain or do whatever it wants but it's strongly recommended to use Test and take advantage of its routines, like in the example. Each test sub is treated as a subtest (ha!) of the package it's included in.

To actually run the tests, just add the option :testing to import in the special sub inline-testing in a test file. When this is called, it will cycle through all subs tagged as tests, grouping them by packages:

use Test;
use Test::Inline :testing;

# The first step is to 'use' each module that contains
# testable subs.  Nothing else needs to be done here.
use Rectangle;   # load any modules with
use Circle;      # subs that have the
use Trapezoid;   # 'is test' trait

# Then, initiate the inline testing
# (counts as a single test with subtests)
inline-testing;

# Conclude testing in the .t file
done-testing();

Version history

• v0.1

  • Initial release

  • All features should work

  • If no issues are found, I'll bump version to 1.0 at the end of 2020.

License and Copyright

Licensed under the Artist License 2.0.© 2020 Matthew Stephen Stuckwisch