NAME

Test::Expander - Expansion of test functionalities that appear to be frequently used while testing.

SYNOPSIS

    # Tries to determine both class and method to be tested automatically,
    # does not create any temporary directory:
    use Test::Expander;

    # Tries to determine both class and method to be tested automatically,
    # does not create any temporary directory,
    # passes the option '-srand' to Test::V0 changing the random seed to the current time in seconds:
    use Test::Expander -srand => time;

    # Tries to determine only the method to be tested automatically, class is explicitly supplied,
    # a temporary directory is created with name corresponing to the template supplied:
    use Test::Expander -target => 'My::Class', -tempdir => { TEMPLATE => 'my_dir.XXXXXXXX' };

DESCRIPTION

Test::Expander combines all advanced possibilities provided by Test2::V0 with some specific functions available in the older module Test::More only (which allows a smooth migration from Test::More-based tests to Test2::V0-based ones) and handy functions from some other modules often used in test suites.

Furthermore, this module provides a recognition of class to be tested (see variable $CLASS below) so that in contrast to Test2::V0 you do not need to specify this explicitly if the path to the test file is in accordance with the name of class to be tested.

A similar recognition is provided in regard to the method / subroutine to be tested (see variables $METHOD and METHOD_REF below) if the base name (without extension) of test file is identical with the name of this method / subroutine.

Finally, a configurable setting of specific environment variables is provided so that there is no need to hard-code this in the test itself.

For the time being the following options are accepted by Test::Expander:

• Options specific for this module only:
  • -target - identical with the same-named option of Test2::V0 and has the same purpose namely the explicit definition of class to be tested as a value of this option;
  • -tempdir - activates creation of a temporary directory by the function tempdir provided by File::Temp::tempdir.
  • -tempfile - activates creation of a temporary file by the method tempfile provided by File::Temp::tempfile.
• All other valid options (i.e. arguments starting with the dash sign -) are forwarded to Test2::V0 along with their values.
• If an argument cannot be recognized as an option, an exception is raised.

The proper application of Test::Expander implies that is is used as the very first in your unit test.

The only exception currently known is the case, when some actions performed on the module level (e.g. determination of constants) base on results of other actions (e.g. mocking of built-ins).

To explain this let us assume that your unit test file should mock the built-in close to verify if the testee properly reacts both on its success and failure. For this purpose a reasonable implementation might look as follows:

    my $closeSuccess = 1;
    BEGIN {
      *CORE::GLOBAL::close = sub (*) { return $closeSuccess ? CORE::close($_[0]) : 0 };
    }

    use Test::Expander;

Furthermore, the automated recognition of name of class to be tested can only work properly if the test file is located in the corresponding subdirectory of t, or xt, or any other folder containing a bunch of test files. For instance, if the class to be tested is Foo::Bar::Baz, then the folder with test files related to this class should be t/Foo/Bar/Baz or xt/Foo/Bar/Baz (the name of the top-level directory in this relative name - t, or xt, or my_test is not important) - otherwise the module name cannot be put into the exported variable $CLASS and, if you want to use this variable, should be supplied as a value of the option -target:

    use Test::Expander -target => 'Foo::Bar::Baz';

What is more, the automated recognition of name of method / subroutine to be tested can only work properly if the base name of the test file without extension (usually .t) is equal to the method / subroutine name. In other words, this recognition only works if the file containing the class mentioned above exists and if this class has the method / subroutine with the same name as the test file base name without extension. If this is the case, the exported variables $METHOD and $METHOD_REF contain the name of method / subroutine to be tested and its reference, correspondingly, otherwise both variables are undefined.

Finally, Test::Expander supports testing inside of a clean environment containing only some clearly specified environment variables required for the particular test. Names and values of these environment variables should be configured in files, which names are identical with pathes to single class levels or method to be tested, and the extension is always .env. For instance, if the test file name is t/Foo/Bar/Baz/myMethod.t, the following approach is applied:

• if the file t/Foo.env exists, its content is used for the initialization of test environment,
• if the file t/Foo/Bar.env exists, its content is used either for extension of test environment initialized in the previous step or for its initialization if the file t/Foo.env does not exist,
• if the file t/Foo/Bar/Baz.env exists, its content is used either for extension of test environment initialized in one of the previous steps or for its initialization if neither the file t/Foo.env nor the file t/Foo/Bar.env exists,
• if the file t/Foo/Bar/Baz/myMethod.env exists, its content will be used either for extension of test environment initialized in one of the previous steps or for its initialization if no one of .env files mentioned above exists.

If the .env files existing on different levels have identical names of environment variables, the priority is the higher the later they have been detected. I.e. VAR = 'VALUE0' in t/Foo/Bar/Baz/myMethod.env overwrites VAR = 'VALUE1' in t/Foo/Bar/Baz.env.

If no one of these .env files exists, the environment will not be changed by Test::Expander during the execution of t/Foo/Bar/Baz/myMethod.t.

An environment configuration file (.env file) is a line-based text file, which content is interpreted as follows:

• if such files don't exist, the %ENV hash remains unchanged;
• otherwise, if at least one of such files exists, the %ENV gets emptied (without localization) and
  • lines not matching the RegEx /^\w+\s\*=\s\*\S/ (some alphanumeric characters representing a name of environment variable, optional blanks, the equal sign, again optional blanks and at least one non-blank character representing the first sign of environment variable value) are skipped;
  • in all other lines the value of the environment variable is everything from the first non-blank character after the equal sign until end of the line;
  • the value of the environment variable is evaluated by the string eval so that

    • constant values must be quoted;

    • variables and subroutines must not be quoted:

        NAME_CONST = 'VALUE'
        NAME_VAR   = $KNIB::App::MyApp::Constants::ABC
        NAME_FUNC  = join(' ', $KNIB::App::MyApp::Constants::DEF)
      

Another feature frequently applied inside of test suites is creation of a temporary directory / file used as an isolated container for some testing actions. The module options -tempdir and -tempfile fully synactically compatible with File::Temp::tempdir / File::Temp::tempfile make sure that such temporary directory / file are created after use Test::Expander and their names are stored in the variables $TEMP_DIR / $TEMP_FILE, correspondingly. Both temporary directory and file are removed by default after execution.

All functions provided by this module are exported by default. These and the exported variables are:

• all functions exported by default from Test2::V0,
• all functions exported by default from Test::Files,
• all functions exported by default from Test::Output,
• all functions exported by default from Test::Warn,
• some functions exported by default from Test::More and often used in older tests but not supported by Test2::V0:
  • BAIL_OUT,
  • is_deeply,
  • new_ok,
  • require_ok,
  • use_ok,
• some functions exported by default from Test::Exception and often used in older tests but not supported by Test2::V0:
  • dies_ok,
  • explain,
  • lives_ok,
  • throws_ok,
• function exported by default from Const::Fast:
  • const,
• some functions exported by request from File::Temp:
  • tempdir,
  • tempfile,
• some functions exported by request from Path::Tiny:
  • cwd,
  • path,
• variable $CLASS containing the name of class to be tested,
• variable $METHOD containing the name of method to be tested,
• variable $METHOD_REF containing the reference to subroutine to be tested.
• variable $TEMP_DIR containing the name of a temporary directory created at compile time if the option -tempdir was supplied.
• variable $TEMP_FILE containing the name of a temporary file created at compile time if the option -tempfile was supplied.

All variables mentioned above are read-only if they are defined after use Test::Expander ....

AUTHOR

Jurij Fajnberg, <fajnbergj at gmail.com>

BUGS

Please report any bugs or feature requests through the web interface at https://github.com/jsf116/Test-Expander/issues.

COPYRIGHT AND LICENSE

LICENSE AND COPYRIGHT

Copyright (c) 2021 Jurij Fajnberg

This program is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.