Code Quality Analysis

Code Quality Analysis
Marty Andrews
@martinjandrews

.com.au

static analysis
=
software analysis without execution

design improvement

improve testability

manage complexity

Whole
Team

Collective Coding
Ownership Standard
Test-Driven
Development

Customer Pair Design Planning
Tests Programming Improvement Game

Simple
Design
Continuous Sustainable
Integration Pace

Metaphor

Small
Releases

circa 2001. duplicated from xprogramming.com

Collective Coding
Ownership Standard
Test-Driven
Development

Pair Design
Programming Improvement

Simple
Design
Continuous Sustainable
Integration Pace
circa 2001. duplicated from xprogramming.com

“A code smell is a surface indication
that usually corresponds to a deeper
problem in the system.”

-- Martin Fowler,
paraphrasing Kent Beck

“If it stinks, change it.”

-- Grandma Beck

code samples from

runwayapp.com

Summary statistics from your Rails app

Look for a good code to test ratio

$ sudo gem install rails
$ rails my_app
$ cd my_app
$ rake stats

~/Data/runway $ rake stats
(in /Users/marty/Data/runway)
+----------------------+-------+-------+---------+---------+-----+-------+
| Name | Lines | LOC | Classes | Methods | M/C | LOC/M |
+----------------------+-------+-------+---------+---------+-----+-------+
| Controllers | 333 | 275 | 12 | 45 | 3| 4|
| Helpers | 113 | 104 | 0| 10 | 0| 8|
| Models | 828 | 681 | 12 | 96 | 8| 5|
| Libraries | 874 | 750 | 24 | 113 | 4| 4|
| Model specs | 1662 | 1395 | 0| 0| 0| 0|
| Controller specs | 544 | 434 | 0| 5| 0| 84 |
| Helper specs | 114 | 95 | 0| 0| 0| 0|
+----------------------+-------+-------+---------+---------+-----+-------+
| Total | 4468 | 3734 | 48 | 269 | 5| 11 |
+----------------------+-------+-------+---------+---------+-----+-------+
Code LOC: 1810 Test LOC: 1924 Code to Test Ratio: 1:1.1

681 | 12 | 96 | 8| 5
750 | 24 | 113 | 4| 4
1395 | 0| 0| 0| 0
434 | 0| 5| 0| 84
95 | 0| 0| 0| 0
-----+---------+---------+-----+-------
3734 | 48 | 269 | 5| 11
-----+---------+---------+-----+-------
4 Code to Test Ratio: 1:1.1

use rake stats for regular
human review

reek
http://wiki.github.com/kevinrutherford/reek

Control Couple Long Parameter List
Duplication Nested Iterators
Feature Envy Uncommunicative
Name
Large Class
Utility Function
Long Method

Look for warnings that you haven’t
thought about

$ sudo gem install reek
$ reek [file ...]

~/Data/runway $ find app -name quot;*.rbquot; | xargs reek

quot;app/controllers/actions_controller.rbquot; -- 3 warnings:
ActionsController#action calls current_user.actions multiple times
(Duplication)
ActionsController#action calls params[id] multiple times (Duplication)
ActionsController#actions calls current_user.actions multiple times
(Duplication)

quot;app/controllers/application.rbquot; -- 1 warnings:
ApplicationController#site_version doesn't depend on instance state
(Utility Function)

quot;app/helpers/home_helper.rbquot; -- 1 warnings:
HomeHelper::folder_tab has approx 6 statements (Long Method)

quot;app/models/token.rbquot; -- 21 warnings:
Token#parse_incubation_day_of_the_month refers to base more than self
(Feature Envy)

ActionsController#action calls current_user.actions multiple times
(Duplication)
ActionsController#action calls params[id] multiple times (Duplication)
ActionsController#actions calls current_user.actions multiple times
(Duplication)

quot;app/controllers/application.rbquot; -- 1 warnings:
ApplicationController#site_version doesn't depend on instance state
(Utility Function)

quot;app/helpers/home_helper.rbquot; -- 1 warnings:
HomeHelper::folder_tab has approx 6 statements (Long Method)

quot;app/models/token.rbquot; -- 21 warnings:
Token#parse_incubation_day_of_the_month refers to base more than self
(Feature Envy)

[Feature Envy] Element#update_from refers to
response more than self

def parse_incubation_day_of_the_month
if @remainder =~ /^(d+)(th|st|nd|rd)$/i
day = $1.to_i
base = day <= @today.day ? @today >> 1 : @today
day -=1 until Date.valid_civil?(base.year, base.month, day)
Date.new(base.year, base.month, day)
end
end

use reek for regular human
review

Flog
http://ruby.sadi.st/Flog.html

Complexity checking of Ruby code

“ABC” like algorithm

Assignments
Branches
Conditionals

$ sudo gem install flog
$ flog [dir ...]

~/Data/runway $ flog app

1426.9: flog total
7.9: flog/method average

89.7: ActionFormat#format
81.7: ActionParser#parse
60.4: Token#parse_incubation_date
42.3: Token#parse_incubation_days
35.2: Token#tokenize
29.8: Token#parse
27.8: Token#parse_period
27.6: Action#apply_defaults_from_name
25.3: Action#none
24.9: RankingsController#update
24.2: ActionsHelper#none
22.9: ActionsHelper#action_contexts
21.9: ActionsHelper#action_tags
20.9: Token#parse_incubation_month
20.2: ActionParser#attributes

[More content removed...]

~/Data/runway $ flog app

1426.9: flog total

29.8: Token#parse
27.8: Token#parse_period


def format
@tokens = []
@semi = false

append(quot;Waiting forquot;) if @action.waiting?
append(@action.name) unless @action.name.blank?

append_with_semi(@action.due_at.strftime(quot;<%d/%m/%Y-%H:%Mquot;)) if @action.solid?
if @action.incubating?
append_with_semi(@action.effective_at.strftime(quot;+%d/%m/%Y-%H:%Mquot;))
elsif [quot;laterquot;, quot;donequot;].include?(@action.status)
append_with_semi(quot;+#{@action.status}quot;)
end

append_with_semi(@action.contexts.sort.map(&:shorthand)) unless @action.contexts.blank?
unless @action.waiting?
append_with_semi(@action.time.shorthand) unless @action.time.blank?
append_with_semi(@action.energy.shorthand) unless @action.energy.blank?
end

append_with_semi(@action.tags.sort.map(&:shorthand)) unless @action.tags.blank?

append(quot;!quot;) if @action.today?

@tokens.flatten.join(quot; quot;)
end

~/Data/rails $ flog .

201079.7: flog total

3841.5: main#none
866.1: Parser#none
709.7: timezone#Europe/London
707.5: timezone#America/St_Johns
695.0: timezone#America/Chicago
693.3: timezone#America/New_York
674.3: timezone#Europe/Dublin
670.9: timezone#America/Halifax
662.2: JoinAssociation#association_join
661.2: timezone#Atlantic/Azores
656.7: timezone#Europe/Lisbon
556.3: timezone#Europe/Brussels


841.5: main#none
866.1: Parser#none
709.7: timezone#Europe/London
707.5: timezone#America/St_Johns
695.0: timezone#America/Chicago
693.3: timezone#America/New_York
674.3: timezone#Europe/Dublin
670.9: timezone#America/Halifax
662.2: JoinAssociation#association_join
661.2: timezone#Atlantic/Azores
656.7: timezone#Europe/Lisbon
556.3: timezone#Europe/Brussels


def association_join
connection = reflection.active_record.connection
join = case reflection.macro
when :has_and_belongs_to_many
quot; #{join_type} %s ON %s.%s = %s.%s quot; % [
table_alias_for(options[:join_table], aliased_join_table_name),
connection.quote_table_name(aliased_join_table_name),
options[:foreign_key] || reflection.active_record.to_s.foreign_key,
connection.quote_table_name(parent.aliased_table_name),
reflection.active_record.primary_key] +
table_name_and_alias,
connection.quote_table_name(aliased_table_name),
klass.primary_key,
options[:association_foreign_key] || klass.to_s.foreign_key
]
when :has_many, :has_one
case
when reflection.options[:through]
through_conditions = through_reflection.options[:conditions] ? quot;AND #{interpolate_s

jt_foreign_key = jt_as_extra = jt_source_extra = jt_sti_extra = nil
first_key = second_key = as_extra = nil

if through_reflection.options[:as] # has_many :through against a polymorphic join
jt_foreign_key = through_reflection.options[:as].to_s + '_id'
jt_as_extra = quot; AND %s.%s = %squot; % [
connection.quote_column_name(through_reflection.options[:as].to_s + '_type'),
klass.quote_value(parent.active_record.base_class.name)
]
else
jt_foreign_key = through_reflection.primary_key_name

]
else
jt_foreign_key = through_reflection.primary_key_name
end

case source_reflection.macro
when :has_many
if source_reflection.options[:as]
first_key = quot;#{source_reflection.options[:as]}_idquot;
second_key = options[:foreign_key] || primary_key
as_extra = quot; AND %s.%s = %squot; % [
connection.quote_column_name(quot;#{source_reflection.options[:as]}_typequot;),
klass.quote_value(source_reflection.active_record.base_class.name)
]
else
first_key = through_reflection.klass.base_class.to_s.foreign_key
second_key = options[:foreign_key] || primary_key
end

unless through_reflection.klass.descends_from_active_record?
jt_sti_extra = quot; AND %s.%s = %squot; % [
connection.quote_column_name(through_reflection.active_record.inheritance_col
through_reflection.klass.quote_value(through_reflection.klass.sti_name)]
end
when :belongs_to
first_key = primary_key
if reflection.options[:source_type]
second_key = source_reflection.association_foreign_key
jt_source_extra = quot; AND %s.%s = %squot; % [
connection.quote_column_name(reflection.source_reflection.options[:foreign_ty
klass.quote_value(reflection.options[:source_type])
]

connection.quote_column_name(reflection.source_reflection.options[:foreign_ty
klass.quote_value(reflection.options[:source_type])
]
else
second_key = source_reflection.primary_key_name
end
end

quot; #{join_type} %s ON (%s.%s = %s.%s%s%s%s) quot; % [
table_alias_for(through_reflection.klass.table_name, aliased_join_table_name),
connection.quote_column_name(parent.primary_key),
connection.quote_column_name(jt_foreign_key),
jt_as_extra, jt_source_extra, jt_sti_extra
]+
quot; #{join_type} %s ON (%s.%s = %s.%s%s) quot; % [
connection.quote_column_name(first_key),
connection.quote_column_name(second_key),
as_extra
]

when reflection.options[:as] && [:has_many, :has_one].include?(reflection.macro)
quot; #{join_type} %s ON %s.%s = %s.%s AND %s.%s = %squot; % [
quot;#{reflection.options[:as]}_idquot;,
parent.primary_key,
quot;#{reflection.options[:as]}_typequot;,

quot;#{reflection.options[:as]}_typequot;,
]
else
foreign_key = options[:foreign_key] || reflection.active_record.name.foreign_key
aliased_table_name,
foreign_key,
parent.aliased_table_name,
reflection.options[:primary_key] || parent.primary_key
]
end
when :belongs_to
reflection.klass.primary_key,
options[:foreign_key] || reflection.primary_key_name
]
else
quot;quot;
end || ''
join << %(AND %s) % [
klass.send(:type_condition, aliased_table_name)] unless klass.descends_from_active_record

[through_reflection, reflection].each do |ref|
join << quot;AND #{interpolate_sql(sanitize_sql(ref.options[:conditions], aliased_table_name)
end

join
end

lib/tasks/quality.rake

require 'flog'

desc quot;Analyze for code complexityquot;
task :flog do
flog = Flog.new
flog.flog_files ['app']
threshold = 30

bad_methods = flog.totals.select do |name, score|
score > threshold
end
bad_methods.sort { |a,b| a[1] <=> b[1] }.each do |name, score|
puts quot;%8.1f: %squot; % [score, name]
end

raise quot;#{bad_methods.size} methods have a flog complexity >
#{threshold}quot; unless bad_methods.empty?
end

~/Data/runway $ rake flog
rake aborted!
5 methods have a flog complexity > 30

Flay
http://ruby.sadi.st/Flay.html

Structural similarity checking of Sexp
nodes (syntax tokens)

Fine grained duplication checking

$ sudo gem install flay
$ flay [dir ...]

~/Data/runway $ flay app

[Processing files...]

Total score (lower is better) = 286

1) Similar code found in :defn (mass = 60)
app/controllers/signups_controller.rb:5
app/controllers/user_sessions_controller.rb:6

2) Similar code found in :if (mass = 54)
app/controllers/forgot_passwords_controller.rb:15

app/helpers/actions_helper.rb:43



def create
user = User.new(params[:signup])
if user.save
head(:status => :created, :location => home_path)
else
head(:status => :unprocessable_entity)
end
end

def create
user_session = UserSession.new(params[:user_session])
if user_session.save
head(:status => :created, :location => home_path)
else
head(:status => :unprocessable_entity)
end
end

actionmailer/install.rb
require 'rbconfig'
require 'find'
require 'ftools'

include Config

# this was adapted from rdoc's install.rb by way of Log4r

$sitedir = CONFIG[quot;sitelibdirquot;]
unless $sitedir
version = CONFIG[quot;MAJORquot;] + quot;.quot; + CONFIG[quot;MINORquot;]
$libdir = File.join(CONFIG[quot;libdirquot;], quot;rubyquot;, version)
$sitedir = $:.find {|x| x =~ /site_ruby/ }
if !$sitedir
$sitedir = File.join($libdir, quot;site_rubyquot;)
elsif $sitedir !~ Regexp.quote(version)
$sitedir = File.join($sitedir, version)
end
end

# the actual gruntwork
Dir.chdir(quot;libquot;)

Find.find(quot;action_mailerquot;, quot;action_mailer.rbquot;) { |f|
if f[-3..-1] == quot;.rbquot;
File::install(f, File.join($sitedir, *f.split(///)), 0644, true)
else
File::makedirs(File.join($sitedir, *f.split(///)))
end
}

activesupport/install.rb
require 'rbconfig'
require 'find'
require 'ftools'

include Config

# this was adapted from rdoc's install.rb by ways of Log4r

unless $sitedir
if !$sitedir
end
end


Find.find(quot;active_supportquot;, quot;active_support.rbquot;) { |f|
else
end
}

activerecord/install.rb
require 'rbconfig'
require 'find'
require 'ftools'

include Config

# this was adapted from rdoc's install.rb by ways of Log4r

unless $sitedir
if !$sitedir
end
end


Find.find(quot;active_recordquot;, quot;active_record.rbquot;) { |f|
else
end
}

actionpack/install.rb
require 'rbconfig'
require 'find'
require 'ftools'

include Config

# this was adapted from rdoc's install.rb by way of Log4r

unless $sitedir
if !$sitedir
end
end


Find.find(quot;action_controllerquot;, quot;action_controller.rbquot;, quot;action_viewquot;, quot;action_view.rbquot;) { |f|
else
end
}


require 'flay'

desc quot;Analyze for code duplicationquot;
task :flay do
threshold = 25
flay = Flay.new({:fuzzy => false, :verbose => false, :mass =>
threshold})
flay.process(*Flay.expand_dirs_to_files(['app']))

flay.report

raise quot;#{flay.masses.size} chunks of code have a duplicate mass >
#{threshold}quot; unless flay.masses.empty?
end

~/Data/runway $ rake flay
Total score (lower is better) = 164


2) Similar code found in :if (mass = 54)
app/controllers/forgot_passwords_controller.rb:15

rake aborted!
3 chunks of code have a duplicate mass > 25

roodi
http://roodi.rubyforge.org/

Class Name Block Cyclomatic Complexity

Method Name Method Cyclomatic
Complexity
Module Name

Assignment In Conditional
Class Line Count
Case Missing Else
Method Line Count
Empty Rescue Body
Module Line Count
For Loop Check

Parameter Number

$ sudo gem install roodi
$ roodi [pattern ...]

~/Data/runway $ roodi quot;app/**/*.rbquot;

app/models/action_format.rb:10

Method name quot;formatquot; has a cyclomatic complexity is 12.

It should be 8 or less.

app/models/action_parser.rb:50

Block cyclomatic complexity is 11.


app/models/action.rb:107

Case statement is missing an else clause.


Method quot;apply_defaults_from_namequot; has 23 lines.

It should have 20 or less.

app/controllers/application.rb:52

Found = in conditional.

It should probably be an ==

Method name quot;formatquot; has a cyclomatic complexit






Case statement is missing an else clause.


Method quot;apply_defaults_from_namequot; has 23 lines.

It should have 20 or less.







meta.each do |token|
case token.klass
when :context
unless token.value.blank?
@contexts ||= []
@contexts << token.value
end
when :time
@time = token.value
when :energy
@energy = token.value
when :tag
@tags << token.value unless token.value.blank?
when :semi_colon
# Ignore
when :available, :today, :later, :done
@status = token.klass.to_s
@effective_at = token.value
when :due_at
@due_at = token.value
end
end




1 meta.each do |token|
case token.klass
2 when :context

3 unless token.value.blank?
@contexts ||= [] 4
@contexts << token.value
end
5 when :time
@time = token.value
6 when :energy
@energy = token.value
7 8
when :tag
@tags << token.value unless token.value.blank?
9 when :semi_colon
# Ignore
10 when :available, :today, :later, :done
@status = token.klass.to_s
@effective_at = token.value
11 when :due_at
@due_at = token.value
end
end




def extract_authenticity_token
if token = request.headers[quot;HTTP_X_RUNWAY_AUTHENTICITY_TOKENquot;]
params[request_forgery_protection_token] = token
end
end

./actionpack/lib/action_controller/vendor/html-
scanner/html/node.rb:417
Method name quot;matchquot;
cyclomatic complexity is 47.

def match(conditions)
conditions = validate_conditions(conditions)
# check content of child nodes
if conditions[:content]
if children.empty?
return false unless match_condition(quot;quot;, conditions[:content])
else
return false unless children.find { |child| child.match(conditions[:content]) }
end
end

# test the name
return false unless match_condition(@name, conditions[:tag]) if conditions[:tag]

# test attributes
(conditions[:attributes] || {}).each do |key, value|
return false unless match_condition(self[key], value)
end

# test parent
return false unless parent.match(conditions[:parent]) if conditions[:parent]

# test children
return false unless children.find { |child| child.match(conditions[:child]) } if conditio

# test ancestors
if conditions[:ancestor]
return false unless catch :found do
p = self
throw :found, true if p.match(conditions[:ancestor]) while p = p.parent
end
end

# test descendants

# test descendants
if conditions[:descendant]
return false unless children.find do |child|
# test the child
child.match(conditions[:descendant]) ||
# test the child's descendants
child.match(:descendant => conditions[:descendant])
end
end

# count children
if opts = conditions[:children]
matches = children.select do |c|
(c.kind_of?(HTML::Tag) and (c.closing == :self or ! c.childless?))
end

matches = matches.select { |c| c.match(opts[:only]) } if opts[:only]
opts.each do |key, value|
next if key == :only
case key
when :count
if Integer === value
return false if matches.length != value
else
return false unless value.include?(matches.length)
end
when :less_than
return false unless matches.length < value
when :greater_than
return false unless matches.length > value
else raise quot;unknown count condition #{key}quot;
end
end
end

else raise quot;unknown count condition #{key}quot;
end
end
end

# test siblings
if conditions[:sibling] || conditions[:before] || conditions[:after]
siblings = parent ? parent.children : []
self_index = siblings.index(self)

if conditions[:sibling]
return false unless siblings.detect do |s|
s != self && s.match(conditions[:sibling])
end
end

if conditions[:before]
return false unless siblings[self_index+1..-1].detect do |s|
s != self && s.match(conditions[:before])
end
end

if conditions[:after]
return false unless siblings[0,self_index].detect do |s|
s != self && s.match(conditions[:after])
end
end
end

true
end


require 'roodi'
require 'roodi_task'

RoodiTask.new 'roodi', ['app/**/*.rb', 'lib/**/*.rb'], 'roodi.yml'

roodi.yml

# AssignmentInConditionalCheck: {}
# CaseMissingElseCheck: {}
ClassLineCountCheck: { line_count: 300 }
ClassNameCheck: { pattern: !ruby/regexp /^[A-Z][a-zA-Z
# ClassVariableCheck: {}
CyclomaticComplexityBlockCheck: { complexity: 8 }
CyclomaticComplexityMethodCheck: { complexity: 10 }
EmptyRescueBodyCheck: { }
ForLoopCheck: { }
MethodLineCountCheck: { line_count: 20 }
MethodNameCheck: { pattern: !ruby/regexp /^[_a-z<>=[|+
ModuleLineCountCheck: { line_count: 300 }
ModuleNameCheck: { pattern: !ruby/regexp /^[A-Z][a-zA-Z
ParameterNumberCheck: { parameter_count: 5 }

~/Data/runway $ rake roodi
app/models/action_format.rb:10 - Method name quot;formatquot; cyclomatic
complexity is 12. It should be 10 or less.
app/models/action_parser.rb:11 - Method name quot;attributesquot; cyclomatic
app/models/action_parser.rb:30 - Method name quot;parsequot; cyclomatic
app/models/token.rb:173 - Method name quot;parse_incubation_datequot;
cyclomatic complexity is 11. It should be 10 or less.
app/models/token.rb:226 - Method name quot;parse_incubation_daysquot;
cyclomatic complexity is 12. It should be 10 or less.
app/models/action_parser.rb:50 - Block cyclomatic complexity is 11.
app/models/token.rb:11 - Block cyclomatic complexity is 10. It should
be 8 or less.
app/models/action.rb:103 - Method quot;apply_defaults_from_namequot; has 23
lines. It should have 20 or less.
app/models/action_parser.rb:30 - Method quot;parsequot; has 23 lines. It
should have 20 or less.
rake aborted!
Found 9 errors.

metric_fu
http://metric-fu.rubyforge.org/

reports on everything you’ve
seen today

plus more!

$ sudo gem sources -a http://gems.github.com
$ sudo gem install jscruggs-metric_fu


require 'metric_fu'

use metrics_fu for regular
human review

lib/tasks/quality.rake (part 1)

require 'flog'

desc quot;Analyze for code complexityquot;
task :flog do
flog = Flog.new
flog.flog_files ['app']
threshold = 40

bad_methods = flog.totals.select do |name, score|
score > threshold
end
bad_methods.sort { |a,b| a[1] <=> b[1] }.each do |name, score|
puts quot;%8.1f: %squot; % [score, name]
end

raise quot;#{bad_methods.size} methods have a flog complexity >
#{threshold}quot; unless bad_methods.empty?
end


require 'flay'

desc quot;Analyze for code duplicationquot;
task :flay do
threshold = 25
flay = Flay.new({:fuzzy => false, :verbose => false, :mass =>
threshold})
flay.process(*Flay.expand_dirs_to_files(['app']))

flay.report

raise quot;#{flay.masses.size} chunks of code have a duplicate mass >
#{threshold}quot; unless flay.masses.empty?
end


require 'roodi'
require 'roodi_task'
require 'metric_fu'

RoodiTask.new 'roodi', ['app/**/*.rb', 'lib/**/*.rb'], 'roodi.yml'

task :quality => [:flog, :flay, :roodi, 'metrics:all']

continuous integration
ﬂog ﬂay roodi

regular human review
metric_fu

rake stats reek and more

Resources
me

@martinjandrews

marty@cogentconsulting.com.au

code samples from

runwayapp.com

reek

wiki.github.com/kevinrutherford/reek
ﬂog

ruby.sadi.st/Flog.html
ﬂay

ruby.sadi.st/Flay.html
roodi

roodi.rubyforge.org
metric_fu

metric-fu.rubyforge.org

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