commit 717e9581ea5005c942507273d15f373de3767d27
Author: Jurij Fajnberg <fajnbergj@gmail.com>
Date:   Mon Nov 1 17:16:06 2021 +0100

    first commit

diff --git a/.gitignore b/.gitignore
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--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+Makefile
+build
diff --git a/Readme.md b/Readme.md
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--- /dev/null
+++ b/Readme.md
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+# NAME
+
+**Test::Expander** - Expansion of test functionalities that appear to be frequently used while testing.
+
+# SYNOPSIS
+
+```perl
+    # 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](https://metacpan.org/pod/Test2::V0)
+with some specific functions available in the older module [Test::More](https://metacpan.org/pod/Test::More) only
+(which allows a smooth migration from [Test::More](https://metacpan.org/pod/Test::More)-based tests to
+[Test2::V0](https://metacpan.org/pod/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 **$CLASS** below) so that
+in contrast to [Test2::V0](https://metacpan.org/pod/Test2::V0) you do not need to specify this explicitly
+if the path to the test file is in accordance with the name of class to be tested.
+
+A similar recognition is provided in regard to the method / subroutine to be tested
+(see variables **$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](https://metacpan.org/pod/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](https://metacpan.org/pod/File::Temp).
+    - **-tempfile** - activates creation of a temporary file by the method **tempfile** provided by
+    [File::Temp::tempfile](https://metacpan.org/pod/File::Temp).
+- All other valid options (i.e. arguments starting with the dash sign **-**) are forwarded to
+[Test2::V0](https://metacpan.org/pod/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:
+
+```perl
+    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 **$CLASS** and, if you want to use this variable,
+should be supplied as a value of the option **-target**:
+
+```perl
+    use Test::Expander -target => 'Foo::Bar::Baz';
+```
+
+What is more, the automated recognition of name of method / subroutine to be tested can only work properly
+if the base name of the test file without extension (usually **.t**) is equal to the method / subroutine
+name. In other words, this recognition only works if the file containing the class mentioned above exists and
+if this class has the method / subroutine with the same name as the test file base name without extension.
+If this is the case, the exported variables **$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](https://perldoc.perl.org/functions/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(' ', $KNIB::App::MyApp::Constants::DEF)
+
+Another feature frequently applied inside of test suites is creation of a temporary directory / file used as an
+isolated container for some testing actions.
+The module options **-tempdir** and **-tempfile** fully synactically compatible with
+[File::Temp::tempdir](https://metacpan.org/pod/File::Temp#FUNCTIONS) /
+[File::Temp::tempfile](https://metacpan.org/pod/File::Temp#FUNCTIONS) make sure that such temporary
+directory / file are created after **use Test::Expander** and their names are stored in the variables
+**$TEMP\_DIR** / **$TEMP\_FILE**, correspondingly.
+Both temporary directory and file are removed by default after execution.
+
+All functions provided by this module are exported by default. These and the exported variables are:
+
+- all functions exported by default from [Test2::V0](https://metacpan.org/pod/Test2::V0),
+- all functions exported by default from [Test::Files](https://metacpan.org/pod/Test::Files),
+- all functions exported by default from [Test::Output](https://metacpan.org/pod/Test::Output),
+- all functions exported by default from [Test::Warn](https://metacpan.org/pod/Test::Warn),
+- some functions exported by default from [Test::More](https://metacpan.org/pod/Test::More)
+and often used in older tests but not supported by [Test2::V0](https://metacpan.org/pod/Test2::V0):
+    - BAIL\_OUT,
+    - is\_deeply,
+    - new\_ok,
+    - require\_ok,
+    - use\_ok,
+- some functions exported by default from [Test::Exception](https://metacpan.org/pod/Test::Exception)
+and often used in older tests but not supported by [Test2::V0](https://metacpan.org/pod/Test2::V0):
+    - dies\_ok,
+    - explain,
+    - lives\_ok,
+    - throws\_ok,
+- function exported by default from [Const::Fast](https://metacpan.org/pod/Const::Fast):
+    - const,
+- some functions exported by request from [File::Temp](https://metacpan.org/pod/File::Temp):
+    - tempdir,
+    - tempfile,
+- some functions exported by request from [Path::Tiny](https://metacpan.org/pod/Path::Tiny):
+    - cwd,
+    - path,
+- variable **$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, &lt;fajnbergj at gmail.com>
+
+# BUGS
+
+Please report any bugs or feature requests through the web interface at
+[https://github.com/jsf116/Test-Expander/issues](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.
diff --git a/lib/.perlcriticrc b/lib/.perlcriticrc
new file mode 100644
index 0000000..c45eac8
--- /dev/null
+++ b/lib/.perlcriticrc
@@ -0,0 +1,379 @@
+# You may disable specific policies appending the following annotation
+#
+# ## no critic (..., ...)
+#
+# to the corresponding code line. To direct perlcritic to ignore the
+# "## no critic" annotations, use the --force option.
+
+# Policies shipped with Perl::Critic 1.125 were considered for the below
+# defintion of the new policy theme "knib".
+
+severity = brutal
+theme    = knib
+verbose  = %f: %m at line %l, column %c.  (Policy: %p)\n
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitLvalueSubstr]
+add_themes = knib
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitStringyEval]
+add_themes     = knib
+allow_includes = 1
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitStringySplit]
+add_themes = knib
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalCan]
+add_themes = knib
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalIsa]
+add_themes = knib
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitUselessTopic]
+# KNOWN BUGS: This policy flags a false positive on reverse() called in list
+# context, since reverse() in list context does not assume $_.
+add_themes = knib
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidGrep]
+add_themes = knib
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidMap]
+add_themes = knib
+
+[Perl::Critic::Policy::BuiltinFunctions::RequireBlockGrep]
+add_themes = knib
+
+[Perl::Critic::Policy::BuiltinFunctions::RequireBlockMap]
+add_themes = knib
+
+# 14.01.2016 policy disabled after a discussion with the team
+#[BuiltinFunctions::RequireGlobFunction]
+#add_themes = knib
+
+[Perl::Critic::Policy::BuiltinFunctions::RequireSimpleSortBlock]
+add_themes = knib
+
+[Perl::Critic::Policy::ClassHierarchies::ProhibitExplicitISA]
+# Note: Some people prefer parent over base.
+add_themes = knib
+
+[Perl::Critic::Policy::CodeLayout::ProhibitHardTabs]
+add_themes         = knib
+allow_leading_tabs = 0
+
+# 14.01.2016 policy disabled after a discussion with the team
+#[Perl::Critic::Policy::CodeLayout::ProhibitQuotedWordLists]
+#add_themes   = knib
+#min_elements = 1
+#strict       = 1
+
+[Perl::Critic::Policy::CodeLayout::ProhibitTrailingWhitespace]
+add_themes = knib
+
+[Perl::Critic::Policy::CodeLayout::RequireConsistentNewlines]
+add_themes = knib
+
+# 14.01.2016 policy disabled after a discussion with the team
+#[Perl::Critic::Policy::CodeLayout::RequireTrailingCommas]
+#add_themes = knib
+
+[Perl::Critic::Policy::ControlStructures::ProhibitCStyleForLoops]
+add_themes = knib
+
+[Perl::Critic::Policy::ControlStructures::ProhibitCascadingIfElse]
+add_themes = knib
+max_elsif  = 1
+
+[Perl::Critic::Policy::ControlStructures::ProhibitDeepNests]
+# Martin Fowler's book "Refactoring: Improving The Design of Existing Code".
+add_themes = knib
+max_nests  = 5
+
+[Perl::Critic::Policy::ControlStructures::ProhibitLabelsWithSpecialBlockNames]
+add_themes = knib
+
+[Perl::Critic::Policy::ControlStructures::ProhibitMutatingListFunctions]
+# Read the LIMITATIONS that this policy has.
+add_themes = knib
+
+[Perl::Critic::Policy::ControlStructures::ProhibitNegativeExpressionsInUnlessAndUntilConditions]
+add_themes = knib
+
+[Perl::Critic::Policy::ControlStructures::ProhibitUnreachableCode]
+add_themes = knib
+
+# Available With Perl::Critic v1.126
+#[Perl::Critic::Policy::ControlStructures::ProhibitYadaOperator]
+#add_themes = knib
+
+[Perl::Critic::Policy::Documentation::PodSpelling]
+add_themes =
+# "spell" is the spell checker avalable on our AIX system. The default spell
+# checker "aspell" was not available.
+spell_command = spell
+#stop_words = ...
+stop_words_file = PodSpelling_stop_words.txt
+
+[Perl::Critic::Policy::Documentation::RequirePackageMatchesPodName]
+add_themes = knib
+
+#[Perl::Critic::Policy::Documentation::RequirePodSections]
+#add_themes = knib
+
+# 14.01.2016 policy disabled after a discussion with the team
+#[Perl::Critic::Policy::ErrorHandling::RequireCheckingReturnValueOfEval]
+#add_themes = knib
+
+[Perl::Critic::Policy::InputOutput::ProhibitBacktickOperators]
+add_themes           = knib
+# 14.01.2016 policy configuration changed after a discussion with the team
+only_in_void_context = 1
+
+[Perl::Critic::Policy::InputOutput::ProhibitBarewordFileHandles]
+add_themes = knib
+
+[Perl::Critic::Policy::InputOutput::ProhibitExplicitStdin]
+add_themes = knib
+
+[Perl::Critic::Policy::InputOutput::ProhibitInteractiveTest]
+add_themes = knib
+
+[Perl::Critic::Policy::InputOutput::ProhibitJoinedReadline]
+add_themes = knib
+
+[Perl::Critic::Policy::InputOutput::ProhibitReadlineInForLoop]
+add_themes = knib
+
+[Perl::Critic::Policy::InputOutput::ProhibitTwoArgOpen]
+add_themes = knib
+
+[Perl::Critic::Policy::InputOutput::RequireBriefOpen]
+# http://www.perlmonks.org/?node_id=1134785
+add_themes = knib
+lines      = 9
+
+[Perl::Critic::Policy::InputOutput::RequireCheckedSyscalls]
+# Covers the policies
+# Perl::Critic::Policy::InputOutput::RequireCheckedClose and
+# Perl::Critic::Policy::InputOutput::RequireCheckedOpen
+add_themes        = knib
+exclude_functions = print say
+functions         = :builtins
+
+[Perl::Critic::Policy::InputOutput::RequireEncodingWithUTF8Layer]
+add_themes = knib
+
+[Perl::Critic::Policy::Miscellanea::ProhibitUnrestrictedNoCritic]
+add_themes = knib
+
+[Perl::Critic::Policy::Miscellanea::ProhibitUselessNoCritic]
+add_themes = knib
+
+[Perl::Critic::Policy::Modules::ProhibitAutomaticExportation]
+add_themes = knib
+
+[Perl::Critic::Policy::Modules::ProhibitConditionalUseStatements]
+add_themes = knib
+
+[Perl::Critic::Policy::Modules::ProhibitEvilModules]
+add_themes = knib
+modules    = Class::ISA Error Pod::Plainer Shell Switch
+
+[Perl::Critic::Policy::Modules::ProhibitExcessMainComplexity]
+# http://en.wikipedia.org/wiki/Cyclomatic_complexity
+add_themes = knib
+max_mccabe = 20
+
+[Perl::Critic::Policy::Modules::ProhibitMultiplePackages]
+add_themes = knib
+
+[Perl::Critic::Policy::Modules::RequireBarewordIncludes]
+add_themes = knib
+
+[Perl::Critic::Policy::Modules::RequireEndWithOne]
+add_themes = knib
+
+[Perl::Critic::Policy::Modules::RequireExplicitPackage]
+add_themes      = knib
+allow_import_of = utf8
+exempt_scripts  = 0
+
+[Perl::Critic::Policy::Modules::RequireFilenameMatchesPackage]
+add_themes = knib
+
+[Perl::Critic::Policy::Modules::RequireNoMatchVarsWithUseEnglish]
+add_themes = knib
+
+[Perl::Critic::Policy::Modules::RequireVersionVar]
+# Read the TO DO section of this policy and think about its implication.
+add_themes = knib
+
+# Perl::Critic::Policy::NamingConventions::Capitalization
+# It takes some time to configure this policy!
+
+[Perl::Critic::Policy::Objects::ProhibitIndirectSyntax]
+add_themes = knib
+# The new() subroutine is configured by default; any additional forbid values
+# are in addition to new().
+forbid     = create destroy
+
+[Perl::Critic::Policy::RegularExpressions::ProhibitFixedStringMatches]
+add_themes = knib
+
+[Perl::Critic::Policy::RegularExpressions::ProhibitSingleCharAlternation]
+add_themes = knib
+
+[Perl::Critic::Policy::RegularExpressions::ProhibitUnusedCapture]
+add_themes = knib
+
+# 14.01.2016 policy still enabled after a discussion with the team
+[Perl::Critic::Policy::RegularExpressions::ProhibitUnusualDelimiters]
+add_themes         = knib
+allow_all_brackets = 0
+
+[Perl::Critic::Policy::RegularExpressions::ProhibitUselessTopic]
+add_themes = knib
+
+[Perl::Critic::Policy::RegularExpressions::RequireBracesForMultiline]
+add_themes         = knib
+allow_all_brackets = 0
+
+[Perl::Critic::Policy::Subroutines::ProhibitAmpersandSigils]
+add_themes = knib
+
+[Perl::Critic::Policy::Subroutines::ProhibitBuiltinHomonyms]
+# Read the CAVEATS.
+add_themes = knib
+
+[Perl::Critic::Policy::Subroutines::ProhibitExcessComplexity]
+# http://en.wikipedia.org/wiki/Cyclomatic_complexity
+add_themes = knib
+max_mccabe = 20
+
+[Perl::Critic::Policy::Subroutines::ProhibitExplicitReturnUndef]
+# http://perlmonks.org/index.pl?node_id=741847
+add_themes = knib
+
+[Perl::Critic::Policy::Subroutines::ProhibitManyArgs]
+add_themes    = knib
+max_arguments = 5
+
+[Perl::Critic::Policy::Subroutines::ProhibitNestedSubs]
+add_themes = knib
+
+[Perl::Critic::Policy::Subroutines::ProhibitReturnSort]
+# KNOWN BUGS: This Policy is not sensitive to the wantarray() function.
+add_themes = knib
+
+[Perl::Critic::Policy::Subroutines::ProhibitSubroutinePrototypes]
+add_themes = knib
+
+[Perl::Critic::Policy::Subroutines::ProhibitUnusedPrivateSubroutines]
+add_themes = knib
+
+[Perl::Critic::Policy::Subroutines::ProtectPrivateSubs]
+add_themes = knib
+
+#[Perl::Critic::Policy::Subroutines::RequireArgUnpacking]
+#add_themes                  = knib
+#allow_delegation_to         = SUPER:: NEXT::
+#allow_subscripts            = 0
+#short_subroutine_statements = 0
+
+[Perl::Critic::Policy::Subroutines::RequireFinalReturn]
+add_themes     = knib
+terminal_funcs = return carp croak die exec exit goto throw
+
+[Perl::Critic::Policy::TestingAndDebugging::ProhibitNoStrict]
+add_themes = knib
+allow      = refs
+
+[Perl::Critic::Policy::TestingAndDebugging::ProhibitNoWarnings]
+add_themes                      = knib
+allow_with_category_restriction = 1
+
+[Perl::Critic::Policy::TestingAndDebugging::ProhibitProlongedStrictureOverride]
+add_themes = knib
+statements = 3
+
+# The following policy seems to have a bug for the ok() test.
+#[Perl::Critic::Policy::TestingAndDebugging::RequireTestLabels]
+#add_themes = knib
+#modules    = Test::Exception Test::More
+
+[Perl::Critic::Policy::TestingAndDebugging::RequireUseStrict]
+add_themes = knib
+
+[Perl::Critic::Policy::TestingAndDebugging::RequireUseWarnings]
+add_themes = knib
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitInterpolationOfLiterals]
+add_themes                            = knib
+allow_if_string_contains_single_quote = 1
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitLeadingZeros]
+add_themes = knib
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitLongChainsOfMethodCalls]
+add_themes       = knib
+max_chain_length = 3
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitMagicNumbers]
+# Not yet configured completely.
+add_themes     = knib
+# 14.01.2016 2 is considered a magic number as well after a discussion with the team
+allowed_values = -1 0 1
+
+# 11.02.2016 policy disabled after a discussion with the team
+#[Perl::Critic::Policy::ValuesAndExpressions::ProhibitMismatchedOperators]
+#add_themes = knib
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitMixedBooleanOperators]
+add_themes = knib
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitQuotesAsQuotelikeOperatorDelimiters]
+add_themes                     = knib
+back_quote_allowed_operators   =
+double_quote_allowed_operators =
+single_quote_allowed_operators =
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitSpecialLiteralHeredocTerminator]
+add_themes = knib
+
+[Perl::Critic::Policy::ValuesAndExpressions::RequireConstantVersion]
+add_themes                             =
+allow_version_without_use_on_same_line = 1
+
+[Perl::Critic::Policy::ValuesAndExpressions::RequireNumberSeparators]
+add_themes = knib
+min_value  = 10000
+
+[Perl::Critic::Policy::ValuesAndExpressions::RequireQuotedHeredocTerminator]
+add_themes = knib
+
+[Perl::Critic::Policy::ValuesAndExpressions::RequireUpperCaseHeredocTerminator]
+add_themes = knib
+
+[Perl::Critic::Policy::Variables::ProhibitConditionalDeclarations]
+add_themes = knib
+
+[Perl::Critic::Policy::Variables::ProhibitLocalVars]
+add_themes = knib
+
+[Perl::Critic::Policy::Variables::ProhibitMatchVars]
+add_themes = knib
+
+[Perl::Critic::Policy::Variables::ProhibitUnusedVariables]
+add_themes = knib
+
+[Perl::Critic::Policy::Variables::RequireInitializationForLocalVars]
+add_themes = knib
+
+[Perl::Critic::Policy::Variables::RequireLexicalLoopIterators]
+add_themes = knib
+
+[Perl::Critic::Policy::Variables::RequireLocalizedPunctuationVars]
+add_themes = knib
+allow      =
+
+[Perl::Critic::Policy::Variables::RequireNegativeIndices]
+add_themes = knib
diff --git a/lib/Test/Expander.pm b/lib/Test/Expander.pm
new file mode 100644
index 0000000..9ae9f4e
--- /dev/null
+++ b/lib/Test/Expander.pm
@@ -0,0 +1,258 @@
+## no critic (ProhibitStringyEval ProhibitSubroutinePrototypes RequireLocalizedPunctuationVars)
+package Test::Expander;
+
+our $VERSION = '1.0.0';                                     ## no critic (RequireUseStrict, RequireUseWarnings)
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline portable recursion);
+no  warnings  qw(experimental);
+
+use Const::Fast;
+use File::chdir;
+use File::Temp       qw(tempdir tempfile);
+use Importer;
+use Path::Tiny       qw(cwd path);
+use Scalar::Readonly qw(readonly_on);
+use Test::Files;
+use Test::Output;
+use Test::Warn;
+use Test2::Tools::Explain;
+use Test2::V0        ();
+
+use Test::Expander::Constants qw(
+  $ANY_EXTENSION
+  $CLASS_HIERARCHY_LEVEL
+  $ERROR_WAS
+  $FALSE
+  $EXCEPTION_PREFIX
+  $INVALID_ENV_ENTRY
+  $INVALID_VALUE
+  $NEW_FAILED $NEW_SUCCEEDED
+  $REPLACEMENT
+  $REQUIRE_DESCRIPTION $REQUIRE_IMPLEMENTATION
+  $SEARCH_PATTERN
+  $TOP_DIR_IN_PATH
+  $TRUE
+  $UNKNOWN_OPTION
+  $USE_DESCRIPTION $USE_IMPLEMENTATION
+  $VERSION_NUMBER
+);
+
+readonly_on($VERSION);
+
+our ($CLASS, $METHOD, $METHOD_REF, $TEMP_DIR, $TEMP_FILE);
+our @EXPORT = (
+  @{Const::Fast::EXPORT},
+  @{Test::Files::EXPORT},
+  @{Test::Output::EXPORT},
+  @{Test::Warn::EXPORT},
+  @{Test2::Tools::Explain::EXPORT},
+  @{Test2::V0::EXPORT},
+  qw(tempdir tempfile),
+  qw(cwd path),
+  qw($CLASS $METHOD $METHOD_REF $TEMP_DIR $TEMP_FILE),
+  qw(BAIL_OUT dies_ok is_deeply lives_ok new_ok require_ok throws_ok use_ok),
+);
+
+*BAIL_OUT = \&bail_out;                                     # Explicit "sub BAIL_OUT" would be untestable
+
+sub dies_ok (&;$) {
+  my ($coderef, $description) = @_;
+
+  eval { $coderef->() };
+
+  return ok($@, $description);
+}
+
+sub import {
+  my ($class, @exports) = @_;
+
+  my %options;
+  while (my $optionName = shift(@exports)) {
+    given ($optionName) {
+      when ('-tempdir') {
+        my $optionValue = shift(@exports);
+        die(sprintf($INVALID_VALUE, $optionName, $optionValue)) if ref($optionValue) ne 'HASH';
+        $TEMP_DIR = tempdir(CLEANUP => 1, %$optionValue);
+      }
+      when ('-tempfile') {
+        my $optionValue = shift(@exports);
+        die(sprintf($INVALID_VALUE, $optionName, $optionValue)) if ref($optionValue) ne 'HASH';
+        my $fileHandle;
+        ($fileHandle, $TEMP_FILE) = tempfile(UNLINK => 1, %$optionValue);
+      }
+      when (/^-\w/) {
+        $options{$optionName} = shift(@exports);
+      }
+      default {
+        die(sprintf($UNKNOWN_OPTION, $optionName, shift(@exports) // ''));
+      }
+    }
+  }
+
+  my  $testFile  = path((caller(2))[1]) =~ s{^/}{}r;        ## no critic (ProhibitMagicNumbers)
+  my ($testRoot) = $testFile =~ $TOP_DIR_IN_PATH;
+  unless (exists($options{-target})) {
+    my $testee = path($testFile)->relative($testRoot)->parent;
+    $options{-target} = join('::', split(qr{/}, $testee))
+      if grep { path($_)->child($testee . '.pm')->is_file } @INC;
+  }
+
+  $METHOD = path($testFile)->basename($ANY_EXTENSION);
+  my $startDir = cwd();
+  _setEnv($METHOD, $options{-target}, $testFile);
+
+  Test2::V0->import(%options);
+  $METHOD_REF = '-target' ~~ %options ? $CLASS->can($METHOD) : undef;
+  $METHOD     = undef unless($METHOD_REF);
+
+  readonly_on($CLASS)      if $CLASS;
+  readonly_on($METHOD)     if $METHOD;
+  readonly_on($METHOD_REF) if $METHOD_REF;
+  readonly_on($TEMP_DIR)   if $TEMP_DIR;
+  readonly_on($TEMP_FILE)  if $TEMP_FILE;
+
+  Importer->import_into($class, scalar(caller), ());
+
+  return;
+}
+
+sub is_deeply ($$;$@) {
+  my ($got, $expected, $title) = @_;
+
+  return is($got, $expected, $title);
+}
+
+sub lives_ok (&;$) {
+  my ($coderef, $description) = @_;
+
+  eval { $coderef->() };
+
+  return ok(!$@, $description);
+}
+
+sub new_ok {
+  my ($class, $args) = @_;
+
+  $args ||= [];
+  my $obj = eval { $class->new(@$args) };
+  ok(!$@, _newTestMessage($class));
+
+  return $obj;
+}
+
+sub require_ok {
+  my ($module) = @_;
+
+  my $package       = caller;
+  my $requireResult = eval(sprintf($REQUIRE_IMPLEMENTATION, $package, $module));
+  ok($requireResult, sprintf($REQUIRE_DESCRIPTION, $module, _error()));
+
+  return $requireResult;
+}
+
+sub throws_ok (&$;$) {
+  my ($coderef, $expecting, $description) = @_;
+
+  eval { $coderef->() };
+
+  return like($@, qr/$expecting/, $description);
+}
+
+sub use_ok ($;@) {
+  my ($module, @imports) = @_;
+
+  my ($package, $filename, $line) = caller(0);
+  $filename =~ y/\n\r/_/;                                   # taken over from Test::More
+
+  my $requireResult = eval(sprintf($USE_IMPLEMENTATION, $package, $module, _useImports(\@imports)));
+  ok(
+    $requireResult,
+    sprintf($USE_DESCRIPTION, $module, _error($SEARCH_PATTERN, sprintf($REPLACEMENT, $filename, $line)))
+  );
+
+  return $requireResult;
+}
+
+sub _error {
+  my ($searchString, $replacementString) = @_;
+
+  return '' if $@ eq '';
+
+  my $error = $ERROR_WAS . $@ =~ s/\n$//mr;
+  $error =~ s/$searchString/$replacementString/m if defined($searchString);
+  return $error;
+}
+
+sub _newTestMessage {
+  my ($class) = @_;
+
+  return $@ ? sprintf($NEW_FAILED, $class, _error()) : sprintf($NEW_SUCCEEDED, $class, $class);
+}
+
+sub _readEnvFile {
+  my ($envFile) = @_;
+
+  my @lines = path($envFile)->lines({ chomp => 1 });
+  my %env;
+  while (my ($index, $line) = each(@lines)) {
+    next unless $line =~ /^ (?<name> \w+) \s* = \s* (?<value> \S .*)/x;
+    $env{$+{name}} = eval($+{value});
+    die(sprintf($INVALID_ENV_ENTRY, $index, $envFile, $line, $@)) if $@;
+  }
+
+  return \%env;
+}
+
+sub _setEnv {
+  my ($method, $class, $testFile) = @_;
+
+  my $envFound = $FALSE;
+  my $newEnv   = {};
+  {
+    local $CWD = $testFile =~ s{/.*}{}r;                    ## no critic (ProhibitLocalVars)
+    ($envFound, $newEnv) = _setEnvHierarchically($class, $envFound, $newEnv);
+  }
+
+  my $envFile = $testFile =~ s/$ANY_EXTENSION/.env/r;
+
+  if (path($envFile)->is_file) {
+    $envFound                   = $TRUE unless $envFound;
+    my $methodEnv               = _readEnvFile($envFile);
+    @$newEnv{keys(%$methodEnv)} = values(%$methodEnv)
+  }
+
+  %ENV = %$newEnv if $envFound;
+
+  return;
+}
+
+sub _setEnvHierarchically {
+  my ($class, $envFound, $newEnv) = @_;
+
+  return ($envFound, $newEnv) unless $class;
+
+  my $classTopLevel;
+  ($classTopLevel, $class) = $class =~ $CLASS_HIERARCHY_LEVEL;
+
+  return ($FALSE, {}) unless path($classTopLevel)->is_dir;
+
+  my $envFile = $classTopLevel . '.env';
+  if (path($envFile)->is_file) {
+    $envFound = $TRUE unless $envFound;
+    $newEnv   = { %$newEnv, %{ _readEnvFile($envFile) } };
+  }
+
+  local $CWD = $classTopLevel;                              ## no critic (ProhibitLocalVars)
+  return _setEnvHierarchically($class, $envFound, $newEnv);
+}
+
+sub _useImports {
+  my ($imports) = @_;
+
+  return @$imports == 1 && $imports->[0] =~ $VERSION_NUMBER ? ' ' . $imports->[0] : '';
+}
+
+1;
diff --git a/lib/Test/Expander.pod b/lib/Test/Expander.pod
new file mode 100644
index 0000000..1ec53e4
--- /dev/null
+++ b/lib/Test/Expander.pod
@@ -0,0 +1,373 @@
+=pod
+
+=head1 NAME
+
+B<Test::Expander> - Expansion of test functionalities that appear to be frequently used while testing.
+
+=head1 SYNOPSIS
+
+  # Tries to determine both class and method to be tested automatically,
+  # does not create any temporary directory:
+  use Test::Expander;
+
+  # Tries to determine both class and method to be tested automatically,
+  # does not create any temporary directory,
+  # passes the option '-srand' to Test::V0 changing the random seed to the current time in seconds:
+  use Test::Expander -srand => time;
+
+  # Tries to determine only the method to be tested automatically, class is explicitly supplied,
+  # a temporary directory is created with name corresponing to the template supplied:
+  use Test::Expander -target => 'My::Class', -tempdir => { TEMPLATE => 'my_dir.XXXXXXXX' };
+
+=head1 DESCRIPTION
+
+B<Test::Expander> combines all advanced possibilities provided by L<Test2::V0|https://metacpan.org/pod/Test2::V0>
+with some specific functions available in the older module L<Test::More|https://metacpan.org/pod/Test::More> only
+(which allows a smooth migration from L<Test::More|https://metacpan.org/pod/Test::More>-based tests to
+L<Test2::V0|https://metacpan.org/pod/Test2::V0>-based ones) and handy functions from some other modules
+often used in test suites.
+
+Furthermore, this module provides a recognition of class to be tested (see variable B<$CLASS> below) so that
+in contrast to L<Test2::V0|https://metacpan.org/pod/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 B<$METHOD> and B<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 B<Test::Expander>:
+
+=over 2
+
+=item
+
+Options specific for this module only:
+
+=over 2
+
+=item
+
+B<-target> - identical with the same-named option of L<Test2::V0|https://metacpan.org/pod/Test2::V0> and
+has the same purpose namely the explicit definition of class to be tested as a value of this option;
+
+=item
+
+B<-tempdir> - activates creation of a temporary directory by the function B<tempdir> provided by
+L<File::Temp::tempdir|https://metacpan.org/pod/File::Temp>.
+
+=item
+
+B<-tempfile> - activates creation of a temporary file by the method B<tempfile> provided by
+L<File::Temp::tempfile|https://metacpan.org/pod/File::Temp>.
+
+=back
+
+=item
+
+All other valid options (i.e. arguments starting with the dash sign B<->) are forwarded to
+L<Test2::V0|https://metacpan.org/pod/Test2::V0> along with their values.
+
+=item
+
+If an argument cannot be recognized as an option, an exception is raised.
+
+=back
+
+The proper application of B<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 B<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 B<t>, or B<xt>, or any other folder
+containing a bunch of test files.
+For instance, if the class to be tested is I<Foo::Bar::Baz>, then the folder with test files
+related to this class should be B<t/>I<Foo>B</>I<Bar>B</>I<Baz> or B<xt/>I<Foo>B</>I<Bar>B</>I<Baz>
+(the name of the top-level directory in this relative name - B<t>, or B<xt>, or B<my_test> is not important) -
+otherwise the module name cannot be put into the exported variable B<$CLASS> and, if you want to use this variable,
+should be supplied as a value of the option B<-target>:
+
+  use Test::Expander -target => 'Foo::Bar::Baz';
+
+What is more, the automated recognition of name of method / subroutine to be tested can only work properly
+if the base name of the test file without extension (usually B<.t>) is equal to the method / subroutine
+name. In other words, this recognition only works if the file containing the class mentioned above exists and
+if this class has the method / subroutine with the same name as the test file base name without extension.
+If this is the case, the exported variables B<$METHOD> and B<$METHOD_REF> contain the name of method / subroutine
+to be tested and its reference, correspondingly, otherwise both variables are undefined.
+
+Finally, B<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 B<.env>.
+For instance, if the test file name is B<t/Foo/Bar/Baz/myMethod.t>, the following approach is applied:
+
+=over 2
+
+=item
+
+if the file B<t/Foo.env> exists, its content is used for the initialization of test environment,
+
+=item
+
+if the file B<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 B<t/Foo.env> does not exist,
+
+=item
+
+if the file B<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 B<t/Foo.env> nor
+the file B<t/Foo/Bar.env> exists,
+
+=item
+
+if the file B<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 B<.env> files mentioned above exists.
+
+=back
+
+If the B<.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. B<VAR = 'VALUE0'> in B<t/Foo/Bar/Baz/myMethod.env> overwrites B<VAR = 'VALUE1'> in B<t/Foo/Bar/Baz.env>.
+
+If no one of these B<.env> files exists, the environment will not be changed by B<Test::Expander>
+during the execution of B<t/Foo/Bar/Baz/myMethod.t>.
+
+An environment configuration file (B<.env> file) is a line-based text file,
+which content is interpreted as follows:
+
+=over 2
+
+=item
+
+if such files don't exist, the B<%ENV> hash remains unchanged;
+
+=item
+
+otherwise, if at least one of such files exists, the B<%ENV> gets emptied (without localization) and
+
+=over 2
+
+=item
+
+lines not matching the RegEx B</^\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;
+
+=item
+
+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;
+
+=item
+
+the value of the environment variable is evaluated by the L<string eval|https://perldoc.perl.org/functions/eval>
+so that
+
+=over 2
+
+=item
+
+constant values must be quoted;
+
+=item
+
+variables and subroutines must not be quoted:
+
+  NAME_CONST = 'VALUE'
+  NAME_VAR   = $KNIB::App::MyApp::Constants::ABC
+  NAME_FUNC  = join(' ', $KNIB::App::MyApp::Constants::DEF)
+
+=back
+
+=back
+
+=back
+
+Another feature frequently applied inside of test suites is creation of a temporary directory / file used as an
+isolated container for some testing actions.
+The module options B<-tempdir> and B<-tempfile> fully synactically compatible with
+L<File::Temp::tempdir|https://metacpan.org/pod/File::Temp#FUNCTIONS> /
+L<File::Temp::tempfile|https://metacpan.org/pod/File::Temp#FUNCTIONS> make sure that such temporary
+directory / file are created after B<use Test::Expander> and their names are stored in the variables
+B<$TEMP_DIR> / B<$TEMP_FILE>, correspondingly.
+Both temporary directory and file are removed by default after execution.
+
+All functions provided by this module are exported by default. These and the exported variables are:
+
+=over 2
+
+=item
+
+all functions exported by default from L<Test2::V0|https://metacpan.org/pod/Test2::V0>,
+
+=item
+
+all functions exported by default from L<Test::Files|https://metacpan.org/pod/Test::Files>,
+
+=item
+
+all functions exported by default from L<Test::Output|https://metacpan.org/pod/Test::Output>,
+
+=item
+
+all functions exported by default from L<Test::Warn|https://metacpan.org/pod/Test::Warn>,
+
+=item
+
+some functions exported by default from L<Test::More|https://metacpan.org/pod/Test::More>
+and often used in older tests but not supported by L<Test2::V0|https://metacpan.org/pod/Test2::V0>:
+
+=over 2
+
+=item
+
+BAIL_OUT,
+
+=item
+
+is_deeply,
+
+=item
+
+new_ok,
+
+=item
+
+require_ok,
+
+=item
+
+use_ok,
+
+=back
+
+=item
+
+some functions exported by default from L<Test::Exception|https://metacpan.org/pod/Test::Exception>
+and often used in older tests but not supported by L<Test2::V0|https://metacpan.org/pod/Test2::V0>:
+
+=over 2
+
+=item
+
+dies_ok,
+
+=item
+
+explain,
+
+=item
+
+lives_ok,
+
+=item
+
+throws_ok,
+
+=back
+
+=item
+
+function exported by default from L<Const::Fast|https://metacpan.org/pod/Const::Fast>:
+
+=over 2
+
+=item
+
+const,
+
+=back
+
+=item
+
+some functions exported by request from L<File::Temp|https://metacpan.org/pod/File::Temp>:
+
+=over 2
+
+=item
+
+tempdir,
+
+=item
+
+tempfile,
+
+=back
+
+=item
+
+some functions exported by request from L<Path::Tiny|https://metacpan.org/pod/Path::Tiny>:
+
+=over 2
+
+=item
+
+cwd,
+
+=item
+
+path,
+
+=back
+
+=item
+
+variable B<$CLASS> containing the name of class to be tested,
+
+=item
+
+variable B<$METHOD> containing the name of method to be tested,
+
+=item
+
+variable B<$METHOD_REF> containing the reference to subroutine to be tested.
+
+=item
+
+variable B<$TEMP_DIR> containing the name of a temporary directory created at compile time
+if the option B<-tempdir> was supplied.
+
+=item
+
+variable B<$TEMP_FILE> containing the name of a temporary file created at compile time
+if the option B<-tempfile> was supplied.
+
+=back
+
+All variables mentioned above are read-only if they are defined after B<use Test::Expander ...>.
+
+=head1 AUTHOR
+
+Jurij Fajnberg, <fajnbergj at gmail.com>
+
+=head1 BUGS
+
+Please report any bugs or feature requests through the web interface at
+L<https://github.com/jsf116/Test-Expander/issues>.
+
+=head1 COPYRIGHT AND LICENSE
+
+=head2 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.
+
+=cut
diff --git a/lib/Test/Expander/Constants.pm b/lib/Test/Expander/Constants.pm
new file mode 100644
index 0000000..b1bdd9e
--- /dev/null
+++ b/lib/Test/Expander/Constants.pm
@@ -0,0 +1,35 @@
+## no critic (RequireVersionVar)
+package Test::Expander::Constants;
+
+use v5.14.2;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline portable recursion);
+
+use Const::Fast;
+use Exporter  qw(import);
+use PadWalker qw(peek_our);
+
+const our $ANY_EXTENSION          => qr/ \. [^.]+ $/x;
+const our $CLASS_HIERARCHY_LEVEL  => qr/^( \w+ ) (?: :: ( .+ ) )?/x;
+const our $ERROR_WAS              => ' Error was: ';
+const our $FALSE                  => 0;
+const our $EXCEPTION_PREFIX       => 'BEGIN failed--compilation aborted at ';
+const our $INVALID_ENV_ENTRY      => "Erroneous line %d of '%s' containing '%s': %s\n";
+const our $INVALID_VALUE          => "Option '%s' passed along with invalid value '%s'\n";
+const our $NEW_FAILED             => '%s->new died.%s';
+const our $NEW_SUCCEEDED          => "An object of class '%s' isa '%s'";
+const our $REPLACEMENT            => $EXCEPTION_PREFIX . '%s line %s.';
+const our $REQUIRE_DESCRIPTION    => 'require %s;%s';
+const our $REQUIRE_IMPLEMENTATION => 'package %s; require %s';
+const our $SEARCH_PATTERN         => $EXCEPTION_PREFIX . '.*$';
+const our $TOP_DIR_IN_PATH        => qr{^ ( [^/]+ )}x;
+const our $TRUE                   => 1;
+const our $UNKNOWN_OPTION         => "Unknown option '%s' => '%s' supplied.\n";
+const our $USE_DESCRIPTION        => 'use %s;%s';
+const our $USE_IMPLEMENTATION     => 'package %s; use %s%s; 1';
+const our $VERSION_NUMBER         => qr/^ \d+ (?: \. \d+ )* $/x;
+
+push(our @EXPORT_OK, keys(%{peek_our(0)}));
+
+1;
diff --git a/t/.perlcriticrc b/t/.perlcriticrc
new file mode 100644
index 0000000..d3da5fe
--- /dev/null
+++ b/t/.perlcriticrc
@@ -0,0 +1,325 @@
+# You may disable specific policies appending the following annotation
+#
+# ## no critic (..., ...)
+#
+# to the corresponding code line. To direct perlcritic to ignore the
+# "## no critic" annotations, use the --force option.
+
+# Policies shipped with Perl::Critic 1.125 were considered for the below
+# defintion of the new policy theme "critic".
+
+severity = brutal
+theme    = critic
+verbose  = %f: %m at line %l, column %c.  (Policy: %p)\n
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitLvalueSubstr]
+add_themes = critic
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitStringyEval]
+add_themes     = critic
+allow_includes = 1
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitStringySplit]
+add_themes = critic
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalCan]
+add_themes = critic
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitUniversalIsa]
+add_themes = critic
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitUselessTopic]
+# KNOWN BUGS: This policy flags a false positive on reverse() called in list
+# context, since reverse() in list context does not assume $_.
+add_themes = critic
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidGrep]
+add_themes = critic
+
+[Perl::Critic::Policy::BuiltinFunctions::ProhibitVoidMap]
+add_themes = critic
+
+[Perl::Critic::Policy::BuiltinFunctions::RequireBlockGrep]
+add_themes = critic
+
+[Perl::Critic::Policy::BuiltinFunctions::RequireBlockMap]
+add_themes = critic
+
+[Perl::Critic::Policy::BuiltinFunctions::RequireSimpleSortBlock]
+add_themes = critic
+
+[Perl::Critic::Policy::ClassHierarchies::ProhibitExplicitISA]
+# Note: Some people prefer parent over base.
+add_themes = critic
+
+[Perl::Critic::Policy::CodeLayout::ProhibitHardTabs]
+add_themes         = critic
+allow_leading_tabs = 0
+
+[Perl::Critic::Policy::CodeLayout::ProhibitTrailingWhitespace]
+add_themes = critic
+
+[Perl::Critic::Policy::CodeLayout::RequireConsistentNewlines]
+add_themes = critic
+
+[Perl::Critic::Policy::ControlStructures::ProhibitCStyleForLoops]
+add_themes = critic
+
+[Perl::Critic::Policy::ControlStructures::ProhibitCascadingIfElse]
+add_themes = critic
+max_elsif  = 1
+
+[Perl::Critic::Policy::ControlStructures::ProhibitDeepNests]
+# Martin Fowler's book "Refactoring: Improving The Design of Existing Code".
+add_themes = critic
+max_nests  = 5
+
+[Perl::Critic::Policy::ControlStructures::ProhibitLabelsWithSpecialBlockNames]
+add_themes = critic
+
+[Perl::Critic::Policy::ControlStructures::ProhibitMutatingListFunctions]
+# Read the LIMITATIONS that this policy has.
+add_themes = critic
+
+[Perl::Critic::Policy::ControlStructures::ProhibitNegativeExpressionsInUnlessAndUntilConditions]
+add_themes = critic
+
+[Perl::Critic::Policy::ControlStructures::ProhibitUnreachableCode]
+add_themes = critic
+
+[Perl::Critic::Policy::Documentation::PodSpelling]
+add_themes =
+
+[Perl::Critic::Policy::Documentation::RequirePackageMatchesPodName]
+add_themes = critic
+
+[Perl::Critic::Policy::InputOutput::ProhibitBacktickOperators]
+add_themes           = critic
+only_in_void_context = 1
+
+[Perl::Critic::Policy::InputOutput::ProhibitBarewordFileHandles]
+add_themes = critic
+
+[Perl::Critic::Policy::InputOutput::ProhibitExplicitStdin]
+add_themes = critic
+
+[Perl::Critic::Policy::InputOutput::ProhibitInteractiveTest]
+add_themes = critic
+
+[Perl::Critic::Policy::InputOutput::ProhibitJoinedReadline]
+add_themes = critic
+
+[Perl::Critic::Policy::InputOutput::ProhibitReadlineInForLoop]
+add_themes = critic
+
+[Perl::Critic::Policy::InputOutput::ProhibitTwoArgOpen]
+add_themes = critic
+
+[Perl::Critic::Policy::InputOutput::RequireBriefOpen]
+# http://www.perlmonks.org/?node_id=1134785
+add_themes = critic
+lines      = 9
+
+[Perl::Critic::Policy::InputOutput::RequireCheckedSyscalls]
+# Covers the policies
+# Perl::Critic::Policy::InputOutput::RequireCheckedClose and
+# Perl::Critic::Policy::InputOutput::RequireCheckedOpen
+add_themes        = critic
+exclude_functions = print say
+functions         = :builtins
+
+[Perl::Critic::Policy::InputOutput::RequireEncodingWithUTF8Layer]
+add_themes = critic
+
+[Perl::Critic::Policy::Miscellanea::ProhibitUnrestrictedNoCritic]
+add_themes = critic
+
+[Perl::Critic::Policy::Miscellanea::ProhibitUselessNoCritic]
+add_themes = critic
+
+[Perl::Critic::Policy::Modules::ProhibitAutomaticExportation]
+add_themes = critic
+
+[Perl::Critic::Policy::Modules::ProhibitConditionalUseStatements]
+add_themes = critic
+
+[Perl::Critic::Policy::Modules::ProhibitEvilModules]
+add_themes = critic
+modules    = Class::ISA Error Pod::Plainer Shell Switch
+
+[Perl::Critic::Policy::Modules::ProhibitExcessMainComplexity]
+# http://en.wikipedia.org/wiki/Cyclomatic_complexity
+add_themes = critic
+max_mccabe = 20
+
+[Perl::Critic::Policy::Modules::ProhibitMultiplePackages]
+add_themes = critic
+
+[Perl::Critic::Policy::Modules::RequireBarewordIncludes]
+add_themes = critic
+
+[Perl::Critic::Policy::Modules::RequireEndWithOne]
+add_themes = critic
+
+[Perl::Critic::Policy::Modules::RequireFilenameMatchesPackage]
+add_themes = critic
+
+[Perl::Critic::Policy::Modules::RequireNoMatchVarsWithUseEnglish]
+add_themes = critic
+
+[Perl::Critic::Policy::Objects::ProhibitIndirectSyntax]
+add_themes = critic
+# The new() subroutine is configured by default; any additional forbid values
+# are in addition to new().
+forbid     = create destroy
+
+[Perl::Critic::Policy::RegularExpressions::ProhibitFixedStringMatches]
+add_themes = critic
+
+[Perl::Critic::Policy::RegularExpressions::ProhibitSingleCharAlternation]
+add_themes = critic
+
+[Perl::Critic::Policy::RegularExpressions::ProhibitUnusedCapture]
+add_themes = critic
+
+[Perl::Critic::Policy::RegularExpressions::ProhibitUnusualDelimiters]
+add_themes         = critic
+allow_all_brackets = 0
+
+[Perl::Critic::Policy::RegularExpressions::ProhibitUselessTopic]
+add_themes = critic
+
+[Perl::Critic::Policy::RegularExpressions::RequireBracesForMultiline]
+add_themes         = critic
+allow_all_brackets = 0
+
+[Perl::Critic::Policy::Subroutines::ProhibitAmpersandSigils]
+add_themes = critic
+
+[Perl::Critic::Policy::Subroutines::ProhibitBuiltinHomonyms]
+# Read the CAVEATS.
+add_themes = critic
+
+[Perl::Critic::Policy::Subroutines::ProhibitExcessComplexity]
+# http://en.wikipedia.org/wiki/Cyclomatic_complexity
+add_themes = critic
+max_mccabe = 20
+
+[Perl::Critic::Policy::Subroutines::ProhibitExplicitReturnUndef]
+# http://perlmonks.org/index.pl?node_id=741847
+add_themes = critic
+
+[Perl::Critic::Policy::Subroutines::ProhibitManyArgs]
+add_themes    = critic
+max_arguments = 5
+
+[Perl::Critic::Policy::Subroutines::ProhibitNestedSubs]
+add_themes = critic
+
+[Perl::Critic::Policy::Subroutines::ProhibitReturnSort]
+# KNOWN BUGS: This Policy is not sensitive to the wantarray() function.
+add_themes = critic
+
+[Perl::Critic::Policy::Subroutines::ProhibitSubroutinePrototypes]
+add_themes = critic
+
+[Perl::Critic::Policy::Subroutines::ProhibitUnusedPrivateSubroutines]
+add_themes = critic
+
+[Perl::Critic::Policy::Subroutines::ProtectPrivateSubs]
+add_themes = critic
+
+[Perl::Critic::Policy::Subroutines::RequireArgUnpacking]
+add_themes                  = critic
+allow_delegation_to         = SUPER:: NEXT::
+allow_subscripts            = 0
+short_subroutine_statements = 0
+
+[Perl::Critic::Policy::Subroutines::RequireFinalReturn]
+add_themes     = critic
+terminal_funcs = return carp croak die exec exit goto throw
+
+[Perl::Critic::Policy::TestingAndDebugging::ProhibitNoStrict]
+add_themes = critic
+allow      = refs
+
+[Perl::Critic::Policy::TestingAndDebugging::ProhibitNoWarnings]
+add_themes                      = critic
+allow_with_category_restriction = 1
+
+[Perl::Critic::Policy::TestingAndDebugging::ProhibitProlongedStrictureOverride]
+add_themes = critic
+statements = 3
+
+[Perl::Critic::Policy::TestingAndDebugging::RequireUseStrict]
+add_themes = critic
+
+[Perl::Critic::Policy::TestingAndDebugging::RequireUseWarnings]
+add_themes = critic
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitInterpolationOfLiterals]
+add_themes                            = critic
+allow_if_string_contains_single_quote = 1
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitLeadingZeros]
+add_themes = critic
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitLongChainsOfMethodCalls]
+add_themes       = critic
+max_chain_length = 3
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitMagicNumbers]
+# Not yet configured completely.
+add_themes     = critic
+allowed_values = -1 0 1
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitMixedBooleanOperators]
+add_themes = critic
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitQuotesAsQuotelikeOperatorDelimiters]
+add_themes                     = critic
+back_quote_allowed_operators   =
+double_quote_allowed_operators =
+single_quote_allowed_operators =
+
+[Perl::Critic::Policy::ValuesAndExpressions::ProhibitSpecialLiteralHeredocTerminator]
+add_themes = critic
+
+[Perl::Critic::Policy::ValuesAndExpressions::RequireConstantVersion]
+add_themes                             = critic
+allow_version_without_use_on_same_line = 1
+
+[Perl::Critic::Policy::ValuesAndExpressions::RequireNumberSeparators]
+add_themes = critic
+min_value  = 10000
+
+[Perl::Critic::Policy::ValuesAndExpressions::RequireQuotedHeredocTerminator]
+add_themes = critic
+
+[Perl::Critic::Policy::ValuesAndExpressions::RequireUpperCaseHeredocTerminator]
+add_themes = critic
+
+[Perl::Critic::Policy::Variables::ProhibitConditionalDeclarations]
+add_themes = critic
+
+[Perl::Critic::Policy::Variables::ProhibitLocalVars]
+add_themes = critic
+
+[Perl::Critic::Policy::Variables::ProhibitMatchVars]
+add_themes = critic
+
+[Perl::Critic::Policy::Variables::ProhibitUnusedVariables]
+add_themes = critic
+
+[Perl::Critic::Policy::Variables::RequireInitializationForLocalVars]
+add_themes = critic
+
+[Perl::Critic::Policy::Variables::RequireLexicalLoopIterators]
+add_themes = critic
+
+[Perl::Critic::Policy::Variables::RequireLocalizedPunctuationVars]
+add_themes = critic
+allow      =
+
+[Perl::Critic::Policy::Variables::RequireNegativeIndices]
+add_themes = critic
diff --git a/t/.proverc b/t/.proverc
new file mode 100644
index 0000000..ee651cd
--- /dev/null
+++ b/t/.proverc
@@ -0,0 +1,4 @@
+--lib
+--recurse
+--shuffle
+-I.
\ No newline at end of file
diff --git a/t/.proverc-cover b/t/.proverc-cover
new file mode 100644
index 0000000..ee651cd
--- /dev/null
+++ b/t/.proverc-cover
@@ -0,0 +1,4 @@
+--lib
+--recurse
+--shuffle
+-I.
\ No newline at end of file
diff --git a/t/Test/Expander/Boilerplate.pm b/t/Test/Expander/Boilerplate.pm
new file mode 100644
index 0000000..6d299b6
--- /dev/null
+++ b/t/Test/Expander/Boilerplate.pm
@@ -0,0 +1,14 @@
+package t::Test::Expander::Boilerplate;
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+sub new {
+  my ($class, @args) = @_;
+
+  return bless([\@args], $class);
+}
+
+1;
diff --git a/t/Test/Expander/NoCLASS/NoMETHOD.t b/t/Test/Expander/NoCLASS/NoMETHOD.t
new file mode 100644
index 0000000..7b2de1f
--- /dev/null
+++ b/t/Test/Expander/NoCLASS/NoMETHOD.t
@@ -0,0 +1,12 @@
+#!/usr/bin/env perl
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use Test::Expander;
+
+is($CLASS, undef, 'there is no class corresponding to this test file');
+
+done_testing();
diff --git a/t/Test/Expander/_error.t b/t/Test/Expander/_error.t
new file mode 100644
index 0000000..a014394
--- /dev/null
+++ b/t/Test/Expander/_error.t
@@ -0,0 +1,28 @@
+#!/usr/bin/env perl
+## no critic (ProtectPrivateSubs RequireLocalizedPunctuationVars)
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use Test::Expander::Constants qw($ERROR_WAS);
+use constant TEST_CASES => {
+  'no exception'                              => { exception => '',    args => [],        output => '' },
+  'exception raised, no replacement required' => { exception => 'ABC', args => [],        output => "${ERROR_WAS}ABC" },
+  'exception raised, replacement required'    => { exception => 'ABC', args => [qw(B b)], output => "${ERROR_WAS}AbC" },
+};
+use Test::Builder::Tester tests => scalar(keys(%{TEST_CASES()}));
+
+use Test::Expander;
+
+foreach my $title (keys(%{TEST_CASES()})) {
+  test_out("ok 1 - $title");
+  $@ = TEST_CASES->{$title}->{exception};
+  is(
+    Test::Expander::_error(@{TEST_CASES->{$title}->{args}}),
+    TEST_CASES->{$title}->{output},
+    $title
+  );
+  test_test($title);
+}
diff --git a/t/Test/Expander/_newTestMessage.t b/t/Test/Expander/_newTestMessage.t
new file mode 100644
index 0000000..a70f6ab
--- /dev/null
+++ b/t/Test/Expander/_newTestMessage.t
@@ -0,0 +1,24 @@
+#!/usr/bin/env perl
+## no critic (ProtectPrivateSubs RequireLocalizedPunctuationVars)
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use Test::Expander::Constants qw($NEW_FAILED $NEW_SUCCEEDED);
+use constant TEST_CASES => {
+  "'new' succeeded" => { exception => '',    output => $NEW_SUCCEEDED },
+  "'new' failed"    => { exception => 'ABC', output => $NEW_FAILED },
+};
+use Test::Builder::Tester tests => scalar(keys(%{TEST_CASES()}));
+
+use Test::Expander;
+
+foreach my $title (keys(%{TEST_CASES()})) {
+  test_out("ok 1 - $title");
+  $@ = TEST_CASES->{$title}->{exception};
+  my $expected = TEST_CASES->{$title}->{output} =~ s/%s/.*/gr;
+  like(Test::Expander::_newTestMessage('CLASS'), qr/$expected/, $title);
+  test_test($title);
+}
diff --git a/t/Test/Expander/_setEnv.t b/t/Test/Expander/_setEnv.t
new file mode 100644
index 0000000..f6467f1
--- /dev/null
+++ b/t/Test/Expander/_setEnv.t
@@ -0,0 +1,99 @@
+#!/usr/bin/env perl
+## no critic (RequireLocalizedPunctuationVars)
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use File::chdir;
+
+use Test::Expander -tempdir => {}, -srand => time;
+
+can_ok($CLASS, $METHOD);
+
+ok(-d $TEMP_DIR, "temporary directory '$TEMP_DIR' created");
+
+my $classPath = $CLASS =~ s{::}{/}gr;
+my $testPath  = path($TEMP_DIR)->child('t');
+$testPath->child($classPath)->mkpath;
+
+{
+  local $CWD   = $testPath->parent->stringify;              ## no critic (ProhibitLocalVars)
+
+  my $testFile = path('t')->child($classPath)->child($METHOD . '.t')->stringify;
+  my $envFile  = path('t')->child($classPath)->child($METHOD . '.env');
+
+  is(Test2::Plugin::SRand->from, 'import arg', "random seed is supplied as 'time'");
+
+  subtest 'env variable filled from a variable' => sub {
+    our $var  = 'abc';
+    my $name  = 'ABC';
+    my $value = '$' . __PACKAGE__ . '::var';
+    $envFile->spew("$name = $value\nJust a comment line");
+    %ENV = (xxx => 'yyy');
+
+    ok(lives { $METHOD_REF->($METHOD, $CLASS, $testFile) }, 'successfully executed');
+    is(\%ENV, { $name => lc($name) },                       "'%ENV' has the expected content");
+  };
+
+  subtest 'env variable filled by a self-implemented sub' => sub {
+    my $name  = 'ABC';
+    my $value = __PACKAGE__ . "::testEnv(lc('$name'))";
+    $envFile->spew("$name = $value");
+    %ENV = (xxx => 'yyy');
+
+    ok(lives { $METHOD_REF->($METHOD, $CLASS, $testFile) }, 'successfully executed');
+    is(\%ENV, { $name => lc($name) },                       "'%ENV' has the expected content");
+  };
+
+  subtest "env variable filled by a 'File::Temp::tempdir'" => sub {
+    my $name  = 'ABC';
+    my $value = 'File::Temp::tempdir';
+    $envFile->spew("$name = $value");
+    %ENV = (xxx => 'yyy');
+
+    ok(lives { $METHOD_REF->($METHOD, $CLASS, $testFile) }, 'successfully executed');
+    is([ keys(%ENV) ], [ $name ],                           "'%ENV' has the expected keys");
+    ok(-d $ENV{$name},                                      'temporary directory exists');
+  };
+
+  subtest 'env file does not exist' => sub {
+    $envFile->remove;
+    %ENV = (xxx => 'yyy');
+
+    ok(lives { $METHOD_REF->($METHOD, $CLASS, $testFile) }, 'successfully executed');
+    is(\%ENV, { xxx => 'yyy' },                             "'%ENV' remained unchanged");
+  };
+
+  subtest 'directory structure does not correspond to class hierarchy' => sub {
+    $envFile->remove;
+    %ENV = (xxx => 'yyy');
+
+    ok(lives { $METHOD_REF->($METHOD, 'ABC::' . $CLASS, $testFile) }, 'successfully executed');
+    is(\%ENV, { xxx => 'yyy' },                                       "'%ENV' remained unchanged");
+  };
+
+  subtest 'env files exist on multiple levels' => sub {
+    path($envFile->parent         . '.env')->spew("A = '1'\nB = '2'");
+    path($envFile->parent->parent . '.env')->spew("C = '0'");
+    $envFile->spew("C = '3'");
+    %ENV = (xxx => 'yyy');
+
+    local $CWD = $TEMP_DIR;                                 ## no critic (ProhibitLocalVars)
+    ok(lives { $METHOD_REF->($METHOD, $CLASS, $testFile) }, 'successfully executed');
+    is(\%ENV, { A => '1', B => '2', C => '3' },             "'%ENV' has the expected content");
+  };
+
+  subtest 'env file invalid' => sub {
+    my $name  = 'ABC';
+    my $value = 'abc->';
+    $envFile->spew("$name = $value");
+
+    like(dies { $METHOD_REF->($METHOD, $CLASS, $testFile) }, qr/syntax error/, 'expected exception raised');
+  };
+}
+
+done_testing();
+
+sub testEnv { return $_[0] }                                ## no critic (RequireArgUnpacking)
diff --git a/t/Test/Expander/_useImports.t b/t/Test/Expander/_useImports.t
new file mode 100644
index 0000000..3246b46
--- /dev/null
+++ b/t/Test/Expander/_useImports.t
@@ -0,0 +1,22 @@
+#!/usr/bin/env perl
+## no critic (ProtectPrivateSubs)
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use constant TEST_CASES => {
+  'module version required'                => { input => [ '1.22.333' ], output => ' 1.22.333' },
+  'single import but not a module version' => { input => [ 'x' ],        output => '' },
+  'multiple imports'                       => { input => [ qw(x y) ],    output => '' },
+};
+use Test::Builder::Tester tests => scalar(keys(%{TEST_CASES()}));
+
+use Test::Expander;
+
+foreach my $title (keys(%{TEST_CASES()})) {
+  test_out("ok 1 - $title");
+  is(Test::Expander::_useImports(TEST_CASES->{$title}->{input}), TEST_CASES->{$title}->{output}, $title);
+  test_test($title);
+}
diff --git a/t/Test/Expander/compare_ok.t b/t/Test/Expander/compare_ok.t
new file mode 100644
index 0000000..b45017b
--- /dev/null
+++ b/t/Test/Expander/compare_ok.t
@@ -0,0 +1,16 @@
+#!/usr/bin/env perl
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use Test::Builder::Tester tests => 1;
+
+use Test::Expander;
+
+my $dir   = path(__FILE__)->parent->child($METHOD);
+my $title = 'execution';
+test_out("ok 1 - $title");
+compare_ok($dir->child('got'), $dir->child('expected'), $title);
+test_test($title);
diff --git a/t/Test/Expander/compare_ok/expected b/t/Test/Expander/compare_ok/expected
new file mode 100644
index 0000000..d84edfd
--- /dev/null
+++ b/t/Test/Expander/compare_ok/expected
@@ -0,0 +1,2 @@
+A
+BC
diff --git a/t/Test/Expander/compare_ok/got b/t/Test/Expander/compare_ok/got
new file mode 100644
index 0000000..d84edfd
--- /dev/null
+++ b/t/Test/Expander/compare_ok/got
@@ -0,0 +1,2 @@
+A
+BC
diff --git a/t/Test/Expander/dies_ok.t b/t/Test/Expander/dies_ok.t
new file mode 100644
index 0000000..70a3505
--- /dev/null
+++ b/t/Test/Expander/dies_ok.t
@@ -0,0 +1,15 @@
+#!/usr/bin/env perl
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use Test::Builder::Tester tests => 1;
+
+use Test::Expander;
+
+my $title = 'execution';
+test_out("ok 1 - $title");
+dies_ok(sub { die() }, $title);
+test_test($title);
diff --git a/t/Test/Expander/import.t b/t/Test/Expander/import.t
new file mode 100644
index 0000000..2fd078c
--- /dev/null
+++ b/t/Test/Expander/import.t
@@ -0,0 +1,98 @@
+#!/usr/bin/env perl
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+my (@functions, @variables);
+BEGIN {
+  use Const::Fast;
+  use File::Temp qw(tempdir tempfile);
+  use Path::Tiny qw(cwd path);
+  use Test::Output;
+  use Test::Warn;
+  use Test2::Tools::Explain;
+  use Test2::V0;
+  @functions = (
+    @{Const::Fast::EXPORT},
+    @{Test::Files::EXPORT},
+    @{Test::Output::EXPORT},
+    @{Test::Warn::EXPORT},
+    @{Test2::Tools::Explain::EXPORT},
+    @{Test2::V0::EXPORT},
+    qw(tempdir tempfile),
+    qw(cwd path),
+    qw(BAIL_OUT dies_ok is_deeply lives_ok new_ok require_ok use_ok),
+  );
+  @variables = qw($CLASS $METHOD $METHOD_REF $TEMP_DIR $TEMP_FILE);
+}
+
+use Scalar::Readonly          qw(readonly_off);
+use Test::Builder::Tester     tests => @functions + @variables + 4;
+
+use Test::Expander            -target   => 'Test::Expander',
+                              -tempdir  => { CLEANUP => 1 },
+                              -tempfile => { UNLINK => 1 };
+use Test::Expander::Constants qw($INVALID_VALUE $UNKNOWN_OPTION);
+
+foreach my $function (sort @functions) {
+  my $title = "$CLASS->can('$function')";
+  test_out("ok 1 - $title");
+  can_ok($CLASS, $function);
+  test_test($title);
+}
+
+foreach my $variable (sort @variables) {
+  my $title = "$CLASS exports '$variable'";
+  test_out("ok 1 - $title");
+  ok(eval("defined($variable)"), $title);                   ## no critic (ProhibitStringyEval)
+  test_test($title);
+}
+
+my $title;
+my $expected;
+
+$title    = "invalid option value of '-tempdir'";
+$expected = $INVALID_VALUE =~ s/%s/.+/gr;
+readonly_off($CLASS);
+readonly_off($METHOD);
+readonly_off($METHOD_REF);
+readonly_off($TEMP_DIR);
+readonly_off($TEMP_FILE);
+test_out("ok 1 - $title");
+like(dies { $CLASS->$METHOD(-tempdir => 1) }, qr/$expected/, $title);
+test_test($title);
+
+$title    = "invalid option value of '-tempfile'";
+$expected = $INVALID_VALUE =~ s/%s/.+/gr;
+readonly_off($CLASS);
+readonly_off($METHOD);
+readonly_off($METHOD_REF);
+readonly_off($TEMP_DIR);
+readonly_off($TEMP_FILE);
+test_out("ok 1 - $title");
+like(dies { $CLASS->$METHOD(-tempfile => 1) }, qr/$expected/, $title);
+test_test($title);
+
+$title    = 'unknown option with some value';
+$expected = $UNKNOWN_OPTION =~ s/%s/.+/gr;
+readonly_off($CLASS);
+readonly_off($METHOD);
+readonly_off($METHOD_REF);
+readonly_off($TEMP_DIR);
+readonly_off($TEMP_FILE);
+test_out("ok 1 - $title");
+like(dies { $CLASS->$METHOD(unknown => 1) }, qr/$expected/, $title);
+test_test($title);
+
+$title    = 'unknown option without value';
+$expected = $UNKNOWN_OPTION =~ s/%s/.+/r =~ s/%s//r;
+readonly_off($CLASS);
+readonly_off($METHOD);
+readonly_off($METHOD_REF);
+readonly_off($TEMP_DIR);
+readonly_off($TEMP_FILE);
+test_out("ok 1 - $title");
+like(dies { $CLASS->$METHOD('unknown') }, qr/$expected/, $title);
+test_test($title);
diff --git a/t/Test/Expander/is_deeply.t b/t/Test/Expander/is_deeply.t
new file mode 100644
index 0000000..5655fc1
--- /dev/null
+++ b/t/Test/Expander/is_deeply.t
@@ -0,0 +1,18 @@
+#!/usr/bin/env perl
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use Clone                 qw(clone);
+use Test::Builder::Tester tests => 1;
+
+use Test::Expander;
+
+my $title = 'execution';
+test_out("ok 1 - $title");
+my $got      = bless({A => 0, B => [(0 .. 1)]}, 'some class');
+my $expected = clone($got);
+is_deeply($got, $expected, $title);
+test_test($title);
diff --git a/t/Test/Expander/lives_ok.t b/t/Test/Expander/lives_ok.t
new file mode 100644
index 0000000..a4da458
--- /dev/null
+++ b/t/Test/Expander/lives_ok.t
@@ -0,0 +1,15 @@
+#!/usr/bin/env perl
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use Test::Builder::Tester tests => 1;
+
+use Test::Expander;
+
+my $title = 'execution';
+test_out("ok 1 - $title");
+lives_ok(sub {}, $title);
+test_test($title);
diff --git a/t/Test/Expander/new_ok.t b/t/Test/Expander/new_ok.t
new file mode 100644
index 0000000..2ba10f3
--- /dev/null
+++ b/t/Test/Expander/new_ok.t
@@ -0,0 +1,24 @@
+#!/usr/bin/env perl
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use constant {
+  CLASS      => 't::Test::Expander::Boilerplate',
+  TEST_CASES => {
+    'no args'       => undef,
+    'args supplied' => [ 0 .. 1 ],
+  },
+};
+use Test::Builder::Tester tests => scalar(keys(%{TEST_CASES()}));
+
+use Test::Expander;
+use t::Test::Expander::Boilerplate;
+
+foreach my $title (keys(%{TEST_CASES()})) {
+  test_out("ok 1 - An object of class '@{[CLASS]}' isa '@{[CLASS]}'");
+  new_ok(CLASS, TEST_CASES->{$title}, $title);
+  test_test($title);
+}
diff --git a/t/Test/Expander/require_ok.t b/t/Test/Expander/require_ok.t
new file mode 100644
index 0000000..3a48c6b
--- /dev/null
+++ b/t/Test/Expander/require_ok.t
@@ -0,0 +1,17 @@
+#!/usr/bin/env perl
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use Test::Builder::Tester tests => 1;
+
+use Test::Expander;
+
+use constant CLASS => 't::Test::Expander::Boilerplate';
+
+my $title = "require @{[CLASS]}";
+test_out("ok 1 - $title;");
+require_ok(CLASS);
+test_test($title);
diff --git a/t/Test/Expander/throws_ok.t b/t/Test/Expander/throws_ok.t
new file mode 100644
index 0000000..65cc7b6
--- /dev/null
+++ b/t/Test/Expander/throws_ok.t
@@ -0,0 +1,16 @@
+#!/usr/bin/env perl
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use Test::Builder::Tester tests => 1;
+
+use Test::Expander;
+
+my $title    = 'execution';
+test_out("ok 1 - $title");
+my $expected = 'DIE TEST';
+throws_ok(sub { die($expected) }, $expected, $title);
+test_test($title);
diff --git a/t/Test/Expander/use_ok.t b/t/Test/Expander/use_ok.t
new file mode 100644
index 0000000..592de86
--- /dev/null
+++ b/t/Test/Expander/use_ok.t
@@ -0,0 +1,17 @@
+#!/usr/bin/env perl
+
+use v5.14;
+use warnings
+  FATAL    => qw(all),
+  NONFATAL => qw(deprecated exec internal malloc newline once portable redefine recursion uninitialized);
+
+use Test::Builder::Tester tests => 1;
+
+use Test::Expander;
+
+use constant CLASS => 't::Test::Expander::Boilerplate';
+
+my $title = "use @{[CLASS]}";
+test_out("ok 1 - $title;");
+use_ok(CLASS);
+test_test($title);