Provided by: libtest-cmd-perl_1.09-3_all 
NAME
Test::Cmd::Common - module for common Test::Cmd error handling
SYNOPSIS
use Test::Cmd::Common;
$test = Test::Cmd::Common->new(string => 'functionality being tested',
prog => 'program_under_test',
);
$test->run(chdir => 'subdir', fail => '$? != 0',
flags => '-x', targets => '.',
stdout => <<_EOF_, stderr => <<_EOF_);
expected standard output
_EOF_
expected error output
_EOF_
$test->subdir('subdir', ...);
$test->read(\$contents, 'file');
$test->read(\@lines, 'file');
$test->write('file', <<_EOF_);
contents of the file
_EOF_
$test->file_matches();
$test->must_exist('file', ['subdir', 'file'], ...);
$test->must_not_exist('file', ['subdir', 'file'], ...);
$test->copy('src_file', 'dst_file');
$test->chmod($mode, 'file', ...);
$test->sleep;
$test->sleep($seconds);
$test->touch('file', ...);
$test->unlink('file', ...);
DESCRIPTION
The "Test::Cmd::Common" module provides a simple, high-level interface for writing tests
of executable commands and scripts, especially commands and scripts that interact with the
file system. All methods throw exceptions and exit on failure. This makes it unnecessary
to add explicit checks for return values, making the test scripts themselves simpler to
write and easier to read.
The "Test::Cmd::Common" class is a subclass of Test::Cmd. In essence, "Test::Cmd::Common"
is a wrapper that treats common Test::Cmd error conditions as exceptions that terminate
the test. You can use "Test::Cmd::Common" directly, or subclass it for your program and
add additional (or override) methods to tailor it to your program's specific needs.
Alternatively, "Test::Cmd::Common" serves as a useful example of how to define your own
Test::Cmd subclass.
The "Test::Cmd::Common" module provides the following importable variables:
$_exe
The executable file suffix. This value is normally available as $Config{_exe} in Perl
version 5.005 and later. The "Test::Cmd::Common" module figures it out via other
means in earlier versions.
$_o The object file suffix. This value is normally available from $Config{_o} in Perl
version 5.005 and later. The "Test::Cmd::Common" module figures it out via other
means in earlier versions.
$_a The library file suffix. This value is normally available from as $Config{_a} in Perl
version 5.005 and later. The "Test::Cmd::Common" module figures it out via other
means in earlier versions.
$_so
The shared library file suffix. This value is normally available as $Config{_so} in
Perl version 5.005 and later. The "Test::Cmd::Common" module figures it out via other
means in earlier versions.
$_is_win32
A Boolean value that reflects whether the current platform is a Win32 system.
METHODS
"new"
Creates a new test environment object. Any arguments are keyword-value pairs that are
passed through to the construct method for the base class from which we inherit our
methods (that is, the Test::Cmd class). In the normal case, this should be the
program to be tested and a description of the functionality being tested:
$test = Test::Cmd::Common->new(prog => 'my_program',
string => 'cool new feature');
By default, methods that match actual versus expected output (the "run", and
"file_matches" methods) use an exact match. Tests that require regular expression
matches can specify this on initialization of the test environment:
$test = Test::Cmd::Common->new(prog => 'my_program',
string => 'cool new feature',
match_sub => \&Test::Cmd::diff_regex);
or by executing the following after initialization of the test environment:
$test->match_sub(\&Test::Cmd::diff_regex);
Creates a temporary working directory for the test environment and changes directory
to it.
Exits NO RESULT if the object can not be created, the temporary working directory can
not be created, or the current directory cannot be changed to the temporary working
directory.
"run"
Runs the program under test, checking that the test succeeded. Arguments are keyword-
value pairs that affect the manner in which the program is executed or the results are
evaluated.
chdir => 'subdir'
fail => 'failure condition' # default is '$? != 0'
flags => 'Cons flags'
stderr => 'expected error output'
stdout => 'expected standard output'
targets => 'targets to build'
The test fails if:
-- The specified failure condition is met. The default failure
condition is '$? != 0', i.e. the program exits unsuccesfully.
A not-uncommon alternative is:
$test->run(fail => '$? == 0'); # expect failure
when testing how the program handles errors.
-- Actual standard output does not match expected standard output
(if any). The expected standard output is an array of lines
or a scalar which will be split on newlines.
-- Actual error output does not match expected error output (if
any). The expected error output is an array of lines or a
scalar which will be split on newlines.
This method will test for NO error output by default if no
expected error output is specified (unlike standard output).
The error output test may be explicitly suppressed by
specifying undef as the "expected" error output:
$test->run(stderr => undef);
By default, this method performs an exact match of actual vs. expected standard output
or error output:
$test->run(stdout => <<_EOF_, stderr => _EOF_);
An expected STDOUT line, which must be matched exactly.
_EOF_
One or more expected STDERR lines,
which must be matched exactly.
_EOF_
Tests that require regular expression matches should be executed using a test
environment that calls the "match_sub" method as follows:
$test->match_sub(\&Test::Cmd::diff_regex);
$test->run(stdout => <<_EOF_, stderr => _EOF_);
An expected (STDOUT|standard output) line\.
_EOF_
One or more expected (STDERR|error output) lines,
which may contain (regexes|regular expressions)\.
_EOF_
"subdir"
Creates one or more subdirectories in the temporary working directory. Exits NO
RESULT if the number of subdirectories actually created does not match the number
expected. For compatibility with its superclass method, returns the number of
subdirectories actually created.
"read"
Reads the contents of a file, depositing the contents in the destination referred to
by the first argument (a scalar or array reference). If the file name is not an
absolute path name, it is relative to the temporary working directory. Exits NO
RESULT if the file could not be read for any reason. For compatibility with its
superclass method, returns TRUE on success.
"write"
Writes a file with the specified contents. If the file name is not an absolute path
name, it is relative to the temporary working directory. Exits NO RESULT if there
were any errors writing the file. For compatibility with its superclass method,
returns TRUE on success.
$test->write('file', <<_EOF_);
contents of the file
_EOF_
"file_matches"
Matches the contents of the specified file (first argument) against the expected
contents. The expected contents are an array of lines or a scalar which will be split
on newlines. By default, each expected line must match exactly its corresponding line
in the file:
$test->file_matches('file', <<_EOF_);
Line #1.
Line #2.
_EOF_
Tests that require regular expression matches should be executed using a test
environment that calls the "match_sub" method as follows:
$test->match_sub(\&Test::Cmd::diff_regex);
$test->file_matches('file', <<_EOF_);
The (1st|first) line\.
The (2nd|second) line\.
_EOF_
"must_exist"
Ensures that the specified files must exist. Files may be specified as an array
reference of directory components, in which case the pathname will be constructed by
concatenating them. Exits FAILED if any of the files does not exist.
"must_not_exist"
Ensures that the specified files must not exist. Files may be specified as an array
reference of directory components, in which case the pathname will be constructed by
concatenating them. Exits FAILED if any of the files exists.
"copy"
Copies a file from the source (first argument) to the destination (second argument).
Exits NO RESULT if the file could not be copied for any reason.
"chmod"
Changes the permissions of a list of files to the specified mode (first argument).
Exits NO RESULT if any file could not be changed for any reason.
"sleep"
Sleeps at least the specified number of seconds. If no number is specified, sleeps at
least a minimum number of seconds necessary to advance file time stamps on the current
system. Sleeping more seconds is all right. Exits NO RESULT if the time slept was
less than specified.
"touch"
Updates the access and modification times of the specified files. Exits NO RESULT if
any file could not be modified for any reason.
"unlink"
Removes the specified files. Exits NO RESULT if any file could not be removed for any
reason.
ENVIRONMENT
The "Test::Cmd::Common" module also uses the "PRESERVE", "PRESERVE_FAIL",
"PRESERVE_NO_RESULT", and "PRESERVE_PASS" environment variables from the Test::Cmd module.
See the Test::Cmd documentation for details.
SEE ALSO
perl(1), Test::Cmd.
The most involved example of using the "Test::Cmd::Common" module to test a real-world
application is the "cons-test" testing suite for the Cons software construction utility.
The suite sub-classes "Test::Cmd::Common" to provide common, application-specific
infrastructure across a large number of end-to-end application tests. The suite, and
other information about Cons, is available at:
http://www.dsmit.com/cons
AUTHOR
Steven Knight, knight@baldmt.com
ACKNOWLEDGEMENTS
Thanks to Johan Holmberg for asking the question that led to the creation of this package.
The general idea of testing commands in this way, as well as the test reporting of the
"pass", "fail" and "no_result" methods, come from the testing framework invented by Peter
Miller for his Aegis project change supervisor. Aegis is an excellent bit of work which
integrates creation and execution of regression tests into the software development
process. Information about Aegis is available at:
http://www.tip.net.au/~millerp/aegis.html