NAME

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

SYNOPSIS

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

  # Tries to automatically determine, which class and method are to be tested,
  # does not create a 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 automatically determine method, class is supplied explicitly,
  # a temporary directory is created with a name corresponing to the supplied template:
  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 only available in the older module Test::More (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 the 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 i.e. file t/Foo/Bar/baz.t -> class Foo::Bar.

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 i.e. file t/Foo/Bar/baz.t -> method Foo::Bar::bar.

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 to the same-named option of Test2::V0 and has the same purpose namely the explicit definition of the class to be tested as the value;

    • -tempdir - activates creation of a temporary directory. The value has to be a hash reference with content as explained in File::Temp::tempdir. This means, you can control the creation of temporary directory by passing of necessary parameters in form of a hash reference or, if the default behavior is required, simply pass the empty hash reference as the option value.

    • -tempfile - activates creation of a temporary file. The value has to be a hash reference with content as explained in File::Temp::tempfile. This means, you can control the creation of temporary file by passing of necessary parameters in form of a hash reference or, if the default behavior is required, simply pass the empty hash reference as the option value.

  • 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.

Test::Expander needs to be the very first module in your test file.

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

To explain this let us assume that your 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;

The automated recognition of name of class to be tested can only work if the test file is located in the corresponding subdirectory. 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 the value of -target:

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

Furthermore, the automated recognition of the name of the method / subroutine to be tested 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 the 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, the names of which are identical with paths to single class levels or the 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 the test environment,

  • if the file t/Foo/Bar.env exists, its content is used either to extend the test environment initialized in the previous step or for its initialization if t/Foo.env does not exist,

  • if the file t/Foo/Bar/Baz.env exists, its content is used either to extend the test environment initialized in one of the previous steps or for its initialization if neither t/Foo.env nor t/Foo/Bar.env exist,

  • if the file t/Foo/Bar/Baz/myMethod.env exists, its content is used either to extend the test environment initialized in one of the previous steps or for its initialization if none of .env files mentioned above exist.

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 none of these .env files exist, the environment isn't 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. Its 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, those elements of %ENV are kept, which names are equal to names found in lines of .env file without values. All remaining elements of 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, optionally followed by the equal sign, again optional blanks, and at least one non-blank character representing the first character 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; if this value is omitted, the corresponding environment variable remains unchanged as it originally was in the %ENV (if it existed there, of course);

    • the value of the environment variable (if provided) 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)

All environment variables set up in this manner are logged to STDOUT using note.

Another common feature within test suites is the creation of a temporary directory / file used as an isolated container for some testing actions. The module options -tempdir and -tempfile are fully syntactically compatible with File::Temp::tempdir / File::Temp::tempfile. They make sure that such temporary directory / file are created after use Test::Expander and that 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 the class to be tested,

  • variable $METHOD containing the name of the method to be tested,

  • variable $METHOD_REF containing the reference to the 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 .... In this case they are logged to STDOUT using note.

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

Copyright (c) 2021-2022 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.