NAME Perl::Refactor - Critique Perl source code for best-practices. SYNOPSIS use Perl::Refactor; my $file = shift; my $refactor = Perl::Refactor->new(); my @violations = $refactor->refactor($file); print @violations; DESCRIPTION Perl::Refactor is an extensible framework for creating and applying coding standards to Perl source code. Essentially, it is a static source code analysis engine. Perl::Refactor is distributed with a number of Perl::Refactor::Enforcer modules that attempt to enforce various coding guidelines. Most Enforcer modules are based on Damian Conway's book Perl Best Practices. However, Perl::Refactor is not limited to PBP and will even support Enforcers that contradict Conway. You can enable, disable, and customize those Polices through the Perl::Refactor interface. You can also create new Enforcer modules that suit your own tastes. For a command-line interface to Perl::Refactor, see the documentation for perlrefactor. If you want to integrate Perl::Refactor with your build process, Test::Perl::Refactor provides an interface that is suitable for test programs. Also, Test::Perl::Refactor::Progressive is useful for gradually applying coding standards to legacy code. For the ultimate convenience (at the expense of some flexibility) see the criticism pragma. Win32 and ActivePerl users can find PPM distributions of Perl::Refactor at <http://theoryx5.uwinnipeg.ca/ppms/> and Alexandr Ciornii's downloadable executable at <http://chorny.net/perl/perlrefactor.html>. If you'd like to try Perl::Refactor without installing anything, there is a web-service available at <http://perlrefactor.com>. The web-service does not yet support all the configuration features that are available in the native Perl::Refactor API, but it should give you a good idea of what it does. You can also invoke the perlrefactor web-service from the command-line by doing an HTTP-post, such as one of these: $> lwp-request -m POST http://perlrefactor.com/perl/refactor.pl < MyModule.pm $> wget -q -O - --post-file=MyModule.pm http://perlrefactor.com/perl/refactor.pl $> curl --data @MyModule.pm http://perlrefactor.com/perl/refactor.pl Please note that the perlrefactor web-service is still alpha code. The URL and interface to the service are subject to change. Also, ActivePerl includes a very slick graphical interface to Perl-Refactor called "perlrefactor-gui". You can get a free community edition of ActivePerl from <http://www.activestate.com>. INTERFACE SUPPORT This is considered to be a public class. Any changes to its interface will go through a deprecation cycle. CONSTRUCTOR "new( [ -profile => $FILE, -severity => $N, -theme => $string, -include => \@PATTERNS, -exclude => \@PATTERNS, -top => $N, -only => $B, -profile-strictness => $PROFILE_STRICTNESS_{WARN|FATAL|QUIET}, -force => $B, -verbose => $N ], -color => $B, -pager => $string, -allow-unsafe => $B, -criticism-fatal => $B)" "new()" Returns a reference to a new Perl::Refactor object. Most arguments are just passed directly into Perl::Refactor::Config, but I have described them here as well. The default value for all arguments can be defined in your .perlrefactorrc file. See the "CONFIGURATION" section for more information about that. All arguments are optional key-value pairs as follows: -profile is a path to a configuration file. If $FILE is not defined, Perl::Refactor::Config attempts to find a .perlrefactorrc configuration file in the current directory, and then in your home directory. Alternatively, you can set the "PERLCRITIC" environment variable to point to a file in another location. If a configuration file can't be found, or if $FILE is an empty string, then all Enforcers will be loaded with their default configuration. See "CONFIGURATION" for more information. -severity is the minimum severity level. Only Enforcer modules that have a severity greater than $N will be applied. Severity values are integers ranging from 1 (least severe violations) to 5 (most severe violations). The default is 5. For a given "-profile", decreasing the "-severity" will usually reveal more Enforcer violations. You can set the default value for this option in your .perlrefactorrc file. Users can redefine the severity level for any Enforcer in their .perlrefactorrc file. See "CONFIGURATION" for more information. If it is difficult for you to remember whether severity "5" is the most or least restrictive level, then you can use one of these named values: SEVERITY NAME ...is equivalent to... SEVERITY NUMBER -------------------------------------------------------- -severity => 'gentle' -severity => 5 -severity => 'stern' -severity => 4 -severity => 'harsh' -severity => 3 -severity => 'cruel' -severity => 2 -severity => 'brutal' -severity => 1 The names reflect how severely the code is criticized: a "gentle" criticism reports only the most severe violations, and so on down to a "brutal" criticism which reports even the most minor violations. -theme is special expression that determines which Enforcers to apply based on their respective themes. For example, the following would load only Enforcers that have a 'bugs' AND 'pbp' theme: my $refactor = Perl::Refactor->new( -theme => 'bugs && pbp' ); Unless the "-severity" option is explicitly given, setting "-theme" silently causes the "-severity" to be set to 1. You can set the default value for this option in your .perlrefactorrc file. See the "POLICY THEMES" section for more information about themes. -include is a reference to a list of string @PATTERNS. Enforcer modules that match at least one "m/$PATTERN/ixms" will always be loaded, irrespective of all other settings. For example: my $refactor = Perl::Refactor->new(-include => ['layout'] -severity => 4); This would cause Perl::Refactor to apply all the "CodeLayout::*" Enforcer modules even though they have a severity level that is less than 4. You can set the default value for this option in your .perlrefactorrc file. You can also use "-include" in conjunction with the "-exclude" option. Note that "-exclude" takes precedence over "-include" when a Enforcer matches both patterns. -exclude is a reference to a list of string @PATTERNS. Enforcer modules that match at least one "m/$PATTERN/ixms" will not be loaded, irrespective of all other settings. For example: my $refactor = Perl::Refactor->new(-exclude => ['strict'] -severity => 1); This would cause Perl::Refactor to not apply the "RequireUseStrict" and "ProhibitNoStrict" Enforcer modules even though they have a severity level that is greater than 1. You can set the default value for this option in your .perlrefactorrc file. You can also use "-exclude" in conjunction with the "-include" option. Note that "-exclude" takes precedence over "-include" when a Enforcer matches both patterns. -single-enforcer is a string "PATTERN". Only one enforcer that matches "m/$PATTERN/ixms" will be used. Enforcers that do not match will be excluded. This option has precedence over the "-severity", "-theme", "-include", "-exclude", and "-only" options. You can set the default value for this option in your .perlrefactorrc file. -top is the maximum number of Violations to return when ranked by their severity levels. This must be a positive integer. Violations are still returned in the order that they occur within the file. Unless the "-severity" option is explicitly given, setting "-top" silently causes the "-severity" to be set to 1. You can set the default value for this option in your .perlrefactorrc file. -only is a boolean value. If set to a true value, Perl::Refactor will only choose from Enforcers that are mentioned in the user's profile. If set to a false value (which is the default), then Perl::Refactor chooses from all the Enforcers that it finds at your site. You can set the default value for this option in your .perlrefactorrc file. -profile-strictness is an enumerated value, one of "$PROFILE_STRICTNESS_WARN" in Perl::Refactor::Utils::Constants (the default), "$PROFILE_STRICTNESS_FATAL" in Perl::Refactor::Utils::Constants, and "$PROFILE_STRICTNESS_QUIET" in Perl::Refactor::Utils::Constants. If set to "$PROFILE_STRICTNESS_FATAL" in Perl::Refactor::Utils::Constants, Perl::Refactor will make certain warnings about problems found in a .perlrefactorrc or file specified via the -profile option fatal. For example, Perl::Refactor normally only "warn"s about profiles referring to non-existent Enforcers, but this value makes this situation fatal. Correspondingly, "$PROFILE_STRICTNESS_QUIET" in Perl::Refactor::Utils::Constants makes Perl::Refactor shut up about these things. -force is a boolean value that controls whether Perl::Refactor observes the magical "## no refactor" annotations in your code. If set to a true value, Perl::Refactor will analyze all code. If set to a false value (which is the default) Perl::Refactor will ignore code that is tagged with these annotations. See "BENDING THE RULES" for more information. You can set the default value for this option in your .perlrefactorrc file. -verbose can be a positive integer (from 1 to 11), or a literal format specification. See Perl::Refactor::Violation for an explanation of format specifications. You can set the default value for this option in your .perlrefactorrc file. -unsafe directs Perl::Refactor to allow the use of Enforcers that are marked as "unsafe" by the author. Such enforcers may compile untrusted code or do other nefarious things. -color and -pager are not used by Perl::Refactor but is provided for the benefit of perlrefactor. -criticism-fatal is not used by Perl::Refactor but is provided for the benefit of criticism. -color-severity-highest, -color-severity-high, -color-severity-medium, -color-severity-low, and -color-severity-lowest are not used by Perl::Refactor, but are provided for the benefit of perlrefactor. Each is set to the Term::ANSIColor color specification to be used to display violations of the corresponding severity. -files-with-violations and -files-without-violations are not used by Perl::Refactor, but are provided for the benefit of perlrefactor, to cause only the relevant filenames to be displayed. METHODS "refactor( $source_code )" Runs the $source_code through the Perl::Refactor engine using all the Enforcers that have been loaded into this engine. If $source_code is a scalar reference, then it is treated as a string of actual Perl code. If $source_code is a reference to an instance of PPI::Document, then that instance is used directly. Otherwise, it is treated as a path to a local file containing Perl code. This method returns a list of Perl::Refactor::Violation objects for each violation of the loaded Enforcers. The list is sorted in the order that the Violations appear in the code. If there are no violations, this method returns an empty list. "add_enforcer( -enforcer => $enforcer_name, -params => \%param_hash )" Creates a Enforcer object and loads it into this Refactor. If the object cannot be instantiated, it will throw a fatal exception. Otherwise, it returns a reference to this Refactor. -enforcer is the name of a Perl::Refactor::Enforcer subclass module. The 'Perl::Refactor::Enforcer' portion of the name can be omitted for brevity. This argument is required. -params is an optional reference to a hash of Enforcer parameters. The contents of this hash reference will be passed into to the constructor of the Enforcer module. See the documentation in the relevant Enforcer module for a description of the arguments it supports. " enforcers() " Returns a list containing references to all the Enforcer objects that have been loaded into this engine. Objects will be in the order that they were loaded. " config() " Returns the Perl::Refactor::Config object that was created for or given to this Refactor. " statistics() " Returns the Perl::Refactor::Statistics object that was created for this Refactor. The Statistics object accumulates data for all files that are analyzed by this Refactor. FUNCTIONAL INTERFACE For those folks who prefer to have a functional interface, The "refactor" method can be exported on request and called as a static function. If the first argument is a hashref, its contents are used to construct a new Perl::Refactor object internally. The keys of that hash should be the same as those supported by the "Perl::Refactor::new" method. Here are some examples: use Perl::Refactor qw(refactor); # Use default parameters... @violations = refactor( $some_file ); # Use custom parameters... @violations = refactor( {-severity => 2}, $some_file ); # As a one-liner %> perl -MPerl::Refactor=refactor -e 'print refactor(shift)' some_file.pm None of the other object-methods are currently supported as static functions. Sorry. CONFIGURATION Most of the settings for Perl::Refactor and each of the Enforcer modules can be controlled by a configuration file. The default configuration file is called .perlrefactorrc. Perl::Refactor will look for this file in the current directory first, and then in your home directory. Alternatively, you can set the "PERLCRITIC" environment variable to explicitly point to a different file in another location. If none of these files exist, and the "-profile" option is not given to the constructor, then all the modules that are found in the Perl::Refactor::Enforcer namespace will be loaded with their default configuration. The format of the configuration file is a series of INI-style blocks that contain key-value pairs separated by '='. Comments should start with '#' and can be placed on a separate line or after the name-value pairs if you desire. Default settings for Perl::Refactor itself can be set before the first named block. For example, putting any or all of these at the top of your configuration file will set the default value for the corresponding constructor argument. severity = 3 #Integer or named level only = 1 #Zero or One force = 0 #Zero or One verbose = 4 #Integer or format spec top = 50 #A positive integer theme = (pbp || security) && bugs #A theme expression include = NamingConventions ClassHierarchies #Space-delimited list exclude = Variables Modules::RequirePackage #Space-delimited list criticism-fatal = 1 #Zero or One color = 1 #Zero or One allow-unsafe = 1 #Zero or One pager = less #pager to pipe output to The remainder of the configuration file is a series of blocks like this: [Perl::Refactor::Enforcer::Category::EnforcerName] severity = 1 set_themes = foo bar add_themes = baz maximum_violations_per_document = 57 arg1 = value1 arg2 = value2 "Perl::Refactor::Enforcer::Category::EnforcerName" is the full name of a module that implements the enforcer. The Enforcer modules distributed with Perl::Refactor have been grouped into categories according to the table of contents in Damian Conway's book Perl Best Practices. For brevity, you can omit the 'Perl::Refactor::Enforcer' part of the module name. "severity" is the level of importance you wish to assign to the Enforcer. All Enforcer modules are defined with a default severity value ranging from 1 (least severe) to 5 (most severe). However, you may disagree with the default severity and choose to give it a higher or lower severity, based on your own coding philosophy. You can set the "severity" to an integer from 1 to 5, or use one of the equivalent names: SEVERITY NAME ...is equivalent to... SEVERITY NUMBER ---------------------------------------------------- gentle 5 stern 4 harsh 3 cruel 2 brutal 1 The names reflect how severely the code is criticized: a "gentle" criticism reports only the most severe violations, and so on down to a "brutal" criticism which reports even the most minor violations. "set_themes" sets the theme for the Enforcer and overrides its default theme. The argument is a string of one or more whitespace-delimited alphanumeric words. Themes are case-insensitive. See "POLICY THEMES" for more information. "add_themes" appends to the default themes for this Enforcer. The argument is a string of one or more whitespace-delimited words. Themes are case-insensitive. See "POLICY THEMES" for more information. "maximum_violations_per_document" limits the number of Violations the Enforcer will return for a given document. Some Enforcers have a default limit; see the documentation for the individual Enforcers to see whether there is one. To force a Enforcer to not have a limit, specify "no_limit" or the empty string for the value of this parameter. The remaining key-value pairs are configuration parameters that will be passed into the constructor for that Enforcer. The constructors for most Enforcer objects do not support arguments, and those that do should have reasonable defaults. See the documentation on the appropriate Enforcer module for more details. Instead of redefining the severity for a given Enforcer, you can completely disable a Enforcer by prepending a '-' to the name of the module in your configuration file. In this manner, the Enforcer will never be loaded, regardless of the "-severity" given to the Perl::Refactor constructor. A simple configuration might look like this: #-------------------------------------------------------------- # I think these are really important, so always load them [TestingAndDebugging::RequireUseStrict] severity = 5 [TestingAndDebugging::RequireUseWarnings] severity = 5 #-------------------------------------------------------------- # I think these are less important, so only load when asked [Variables::ProhibitPackageVars] severity = 2 [ControlStructures::ProhibitPostfixControls] allow = if unless # My custom configuration severity = cruel # Same as "severity = 2" #-------------------------------------------------------------- # Give these enforcers a custom theme. I can activate just # these enforcers by saying `perlrefactor -theme larry` [Modules::RequireFilenameMatchesPackage] add_themes = larry [TestingAndDebugging::RequireTestLables] add_themes = larry curly moe #-------------------------------------------------------------- # I do not agree with these at all, so never load them [-NamingConventions::Capitalization] [-ValuesAndExpressions::ProhibitMagicNumbers] #-------------------------------------------------------------- # For all other Enforcers, I accept the default severity, # so no additional configuration is required for them. For additional configuration examples, see the perlrefactorrc file that is included in this examples directory of this distribution. Damian Conway's own Perl::Refactor configuration is also included in this distribution as examples/perlrefactorrc-conway. THE POLICIES A large number of Enforcer modules are distributed with Perl::Refactor. They are described briefly in the companion document Perl::Refactor::EnforcerSummary and in more detail in the individual modules themselves. Say ""perlrefactor -doc PATTERN"" to see the perldoc for all Enforcer modules that match the regex "m/PATTERN/ixms" There are a number of distributions of additional enforcers on CPAN. If Perl::Refactor doesn't contain a enforcer that you want, some one may have already written it. See the "SEE ALSO" section below for a list of some of these distributions. POLICY THEMES Each Enforcer is defined with one or more "themes". Themes can be used to create arbitrary groups of Enforcers. They are intended to provide an alternative mechanism for selecting your preferred set of Enforcers. For example, you may wish disable a certain subset of Enforcers when analyzing test programs. Conversely, you may wish to enable only a specific subset of Enforcers when analyzing modules. The Enforcers that ship with Perl::Refactor have been broken into the following themes. This is just our attempt to provide some basic logical groupings. You are free to invent new themes that suit your needs. THEME DESCRIPTION -------------------------------------------------------------------------- core All enforcers that ship with Perl::Refactor pbp Enforcers that come directly from "Perl Best Practices" bugs Enforcers that that prevent or reveal bugs certrec Enforcers that CERT recommends certrule Enforcers that CERT considers rules maintenance Enforcers that affect the long-term health of the code cosmetic Enforcers that only have a superficial effect complexity Enforcers that specificaly relate to code complexity security Enforcers that relate to security issues tests Enforcers that are specific to test programs Any Enforcer may fit into multiple themes. Say "perlrefactor -list" to get a listing of all available Enforcers and the themes that are associated with each one. You can also change the theme for any Enforcer in your .perlrefactorrc file. See the "CONFIGURATION" section for more information about that. Using the "-theme" option, you can create an arbitrarily complex rule that determines which Enforcers will be loaded. Precedence is the same as regular Perl code, and you can use parentheses to enforce precedence as well. Supported operators are: Operator Altertative Example ----------------------------------------------------------------- && and 'pbp && core' || or 'pbp || (bugs && security)' ! not 'pbp && ! (portability || complexity)' Theme names are case-insensitive. If the "-theme" is set to an empty string, then it evaluates as true all Enforcers. BENDING THE RULES Perl::Refactor takes a hard-line approach to your code: either you comply or you don't. In the real world, it is not always practical (nor even possible) to fully comply with coding standards. In such cases, it is wise to show that you are knowingly violating the standards and that you have a Damn Good Reason (DGR) for doing so. To help with those situations, you can direct Perl::Refactor to ignore certain lines or blocks of code by using annotations: require 'LegacyLibaray1.pl'; ## no refactor require 'LegacyLibrary2.pl'; ## no refactor for my $element (@list) { ## no refactor $foo = ""; #Violates 'ProhibitEmptyQuotes' $barf = bar() if $foo; #Violates 'ProhibitPostfixControls' #Some more evil code... ## use refactor #Some good code... do_something($_); } The "## no refactor" annotations direct Perl::Refactor to ignore the remaining lines of code until a "## use refactor" annotation is found. If the ""## no refactor"" annotation is on the same line as a code statement, then only that line of code is overlooked. To direct perlrefactor to ignore the ""## no refactor"" annotations, use the "--force" option. A bare "## no refactor" annotation disables all the active Enforcers. If you wish to disable only specific Enforcers, add a list of Enforcer names as arguments, just as you would for the "no strict" or ""no warnings"" pragmas. For example, this would disable the "ProhibitEmptyQuotes" and "ProhibitPostfixControls" enforcers until the end of the block or until the next "## use refactor" annotation (whichever comes first): ## no refactor (EmptyQuotes, PostfixControls) # Now exempt from ValuesAndExpressions::ProhibitEmptyQuotes $foo = ""; # Now exempt ControlStructures::ProhibitPostfixControls $barf = bar() if $foo; # Still subjected to ValuesAndExpression::RequireNumberSeparators $long_int = 10000000000; Since the Enforcer names are matched against the "## no refactor" arguments as regular expressions, you can abbreviate the Enforcer names or disable an entire family of Enforcers in one shot like this: ## no refactor (NamingConventions) # Now exempt from NamingConventions::Capitalization my $camelHumpVar = 'foo'; # Now exempt from NamingConventions::Capitalization sub camelHumpSub {} The argument list must be enclosed in parentheses and must contain one or more comma-separated barewords (e.g. don't use quotes). The "## no refactor" annotations can be nested, and Enforcers named by an inner annotation will be disabled along with those already disabled an outer annotation. Some Enforcers like "Subroutines::ProhibitExcessComplexity" apply to an entire block of code. In those cases, "## no refactor" must appear on the line where the violation is reported. For example: sub complicated_function { ## no refactor (ProhibitExcessComplexity) # Your code here... } Enforcers such as "Documentation::RequirePodSections" apply to the entire document, in which case violations are reported at line 1. Use this feature wisely. "## no refactor" annotations should be used in the smallest possible scope, or only on individual lines of code. And you should always be as specific as possible about which Enforcers you want to disable (i.e. never use a bare "## no refactor"). If Perl::Refactor complains about your code, try and find a compliant solution before resorting to this feature. THE Perl::Refactor PHILOSOPHY Coding standards are deeply personal and highly subjective. The goal of Perl::Refactor is to help you write code that conforms with a set of best practices. Our primary goal is not to dictate what those practices are, but rather, to implement the practices discovered by others. Ultimately, you make the rules -- Perl::Refactor is merely a tool for encouraging consistency. If there is a enforcer that you think is important or that we have overlooked, we would be very grateful for contributions, or you can simply load your own private set of enforcers into Perl::Refactor. EXTENDING THE CRITIC The modular design of Perl::Refactor is intended to facilitate the addition of new Enforcers. You'll need to have some understanding of PPI, but most Enforcer modules are pretty straightforward and only require about 20 lines of code. Please see the Perl::Refactor::DEVELOPER file included in this distribution for a step-by-step demonstration of how to create new Enforcer modules. If you develop any new Enforcer modules, feel free to send them to "<jeff@imaginative-software.com>" and I'll be happy to put them into the Perl::Refactor distribution. Or if you would like to work on the Perl::Refactor project directly, check out our repository at <http://perlrefactor.tigris.org>. To subscribe to our mailing list, send a message to <mailto:dev-subscribe@perlrefactor.tigris.org>. The Perl::Refactor team is also available for hire. If your organization has its own coding standards, we can create custom Enforcers to enforce your local guidelines. Or if your code base is prone to a particular defect pattern, we can design Enforcers that will help you catch those costly defects before they go into production. To discuss your needs with the Perl::Refactor team, just contact "<jeff@imaginative-software.com>". PREREQUISITES Perl::Refactor requires the following modules: B::Keywords Config::Tiny Email::Address Exception::Class File::Spec File::Spec::Unix IO::String List::MoreUtils List::Util Module::Pluggable Perl::Tidy Pod::Spell PPI Pod::PlainText Pod::Select Pod::Usage Readonly Scalar::Util String::Format Task::Weaken Text::ParseWords version The following modules are optional, but recommended for complete functionality: File::HomeDir File::Which CONTACTING THE DEVELOPMENT TEAM You are encouraged to subscribe to the mailing list; send a message to <mailto:users-subscribe@perlrefactor.tigris.org>. See also the archives at <http://perlrefactor.tigris.org/servlets/SummarizeList?listName=users>. You can also contact the author at "<jeff@imaginative-software.com>". At least one member of the development team has started hanging around in <irc://irc.perl.org/#perlrefactor>. You can also follow Perl::Refactor on Twitter, at <https://twitter.com/perlrefactor>. SEE ALSO There are a number of distributions of additional Enforcers available. A few are listed here: Perl::Refactor::More Perl::Refactor::Bangs Perl::Refactor::Lax Perl::Refactor::StricterSubs Perl::Refactor::Swift Perl::Refactor::Tics These distributions enable you to use Perl::Refactor in your unit tests: Test::Perl::Refactor Test::Perl::Refactor::Progressive There is also a distribution that will install all the Perl::Refactor related modules known to the development team: Task::Perl::Refactor If you want to make sure you have absolutely everything, you can use this: Task::Perl::Refactor::IncludingOptionalDependencies BUGS Scrutinizing Perl code is hard for humans, let alone machines. If you find any bugs, particularly false-positives or false-negatives from a Perl::Refactor::Enforcer, please submit them to <https://github.com/Perl-Refactor/Perl-Refactor/issues>. Thanks. Most enforcers will produce false-negatives if they cannot understand a particular block of code. CREDITS Adam Kennedy - For creating PPI, the heart and soul of Perl::Refactor. Damian Conway - For writing Perl Best Practices, finally :) Chris Dolan - For contributing the best features and Enforcer modules. Andy Lester - Wise sage and master of all-things-testing. Elliot Shank - The self-proclaimed quality freak. Giuseppe Maxia - For all the great ideas and positive encouragement. and Sharon, my wife - For putting up with my all-night code sessions. Thanks also to the Perl Foundation for providing a grant to support Chris Dolan's project to implement twenty PBP enforcers. <http://www.perlfoundation.org/april_1_2007_new_grant_awards> AUTHOR Jeffrey Ryan Thalhammer <jeff@imaginative-software.com> COPYRIGHT Copyright (c) 2005-2011 Imaginative Software Systems. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of this license can be found in the LICENSE file included with this module.