Code Quality Analysis
Marty Andrews
@martinjandrews
.com.au

static analysis
=
software analysis without execution

no app runtime required!

feedback!

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

smell the
code

“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

Tools

code samples from
runwayapp.com

rake stats

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

Searches for code smells

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 \"*.rb\" | xargs reek
\"app/controllers/actions_controller.rb\" -- 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)
\"app/controllers/application.rb\" -- 1 warnings:
ApplicationController#site_version doesn't depend on instance state
(Utility Function)
\"app/helpers/home_helper.rb\" -- 1 warnings:
HomeHelper::folder_tab has approx 6 statements (Long Method)
\"app/models/token.rb\" -- 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)
\"app/controllers/application.rb\" -- 1 warnings:
ApplicationController#site_version doesn't depend on instance state
(Utility Function)
\"app/helpers/home_helper.rb\" -- 1 warnings:
HomeHelper::folder_tab has approx 6 statements (Long Method)
\"app/models/token.rb\" -- 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

What about Rails?

10,645 warnings

use reek for regular human
review

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

Complexity checking of Ruby code

“ABC” like algorithm
Assignments
Branches
Conditionals

Look for high scores (> 40)

$ 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
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

89.7: ActionFormat#format
def format
@tokens = []
@semi = false
append(\"Waiting for\") if @action.waiting?
append(@action.name) unless @action.name.blank?
append_with_semi(@action.due_at.strftime(\"<%d/%m/%Y-%H:%M\")) if @action.solid?
if @action.incubating?
append_with_semi(@action.effective_at.strftime(\"+%d/%m/%Y-%H:%M\"))
elsif [\"later\", \"done\"].include?(@action.status)
append_with_semi(\"+#{@action.status}\")
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(\"!\") if @action.today?
@tokens.flatten.join(\" \")
end

What about Rails?

~/Data/rails $ flog .
201079.7: flog total
14.1: flog/method average
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
[More content removed...]

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
[More content removed...]

def association_join
connection = reflection.active_record.connection
join = case reflection.macro
when :has_and_belongs_to_many
\" #{join_type} %s ON %s.%s = %s.%s \" % [
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] +
\" #{join_type} %s ON %s.%s = %s.%s \" % [
table_name_and_alias,
connection.quote_table_name(aliased_table_name),
klass.primary_key,
connection.quote_table_name(aliased_join_table_name),
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] ? \"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 = \" AND %s.%s = %s\" % [
connection.quote_table_name(aliased_join_table_name),
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 = \"#{source_reflection.options[:as]}_id\"
second_key = options[:foreign_key] || primary_key
as_extra = \" AND %s.%s = %s\" % [
connection.quote_table_name(aliased_table_name),
connection.quote_column_name(\"#{source_reflection.options[:as]}_type\"),
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 = \" AND %s.%s = %s\" % [
connection.quote_table_name(aliased_join_table_name),
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 = \" AND %s.%s = %s\" % [
connection.quote_table_name(aliased_join_table_name),
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
\" #{join_type} %s ON (%s.%s = %s.%s%s%s%s) \" % [
table_alias_for(through_reflection.klass.table_name, aliased_join_table_name),
connection.quote_table_name(parent.aliased_table_name),
connection.quote_column_name(parent.primary_key),
connection.quote_table_name(aliased_join_table_name),
connection.quote_column_name(jt_foreign_key),
jt_as_extra, jt_source_extra, jt_sti_extra
]+
\" #{join_type} %s ON (%s.%s = %s.%s%s) \" % [
table_name_and_alias,
connection.quote_table_name(aliased_table_name),
connection.quote_column_name(first_key),
connection.quote_table_name(aliased_join_table_name),
connection.quote_column_name(second_key),
as_extra
]
when reflection.options[:as] && [:has_many, :has_one].include?(reflection.macro)
\" #{join_type} %s ON %s.%s = %s.%s AND %s.%s = %s\" % [
table_name_and_alias,
connection.quote_table_name(aliased_table_name),
\"#{reflection.options[:as]}_id\",
connection.quote_table_name(parent.aliased_table_name),
parent.primary_key,
connection.quote_table_name(aliased_table_name),
\"#{reflection.options[:as]}_type\",
klass.quote_value(parent.active_record.base_class.name)

connection.quote_table_name(aliased_table_name),
\"#{reflection.options[:as]}_type\",
klass.quote_value(parent.active_record.base_class.name)
]
else
foreign_key = options[:foreign_key] || reflection.active_record.name.foreign_key
\" #{join_type} %s ON %s.%s = %s.%s \" % [
table_name_and_alias,
aliased_table_name,
foreign_key,
parent.aliased_table_name,
reflection.options[:primary_key] || parent.primary_key
]
end
when :belongs_to
\" #{join_type} %s ON %s.%s = %s.%s \" % [
table_name_and_alias,
connection.quote_table_name(aliased_table_name),
reflection.klass.primary_key,
connection.quote_table_name(parent.aliased_table_name),
options[:foreign_key] || reflection.primary_key_name
]
else
\"\"
end || ''
join << %(AND %s) % [
klass.send(:type_condition, aliased_table_name)] unless klass.descends_from_active_record
[through_reflection, reflection].each do |ref|
join << \"AND #{interpolate_sql(sanitize_sql(ref.options[:conditions], aliased_table_name)
end
join
end

automation

lib/tasks/quality.rake
require 'flog'
desc \"Analyze for code complexity\"
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 \"%8.1f: %s\" % [score, name]
end
raise \"#{bad_methods.size} methods have a flog complexity >
#{threshold}\" unless bad_methods.empty?
end

~/Data/runway $ rake flog
(in /Users/marty/Data/runway)
35.2: Token#tokenize
42.3: Token#parse_incubation_days
60.4: Token#parse_incubation_date
81.7: ActionParser#parse
89.7: ActionFormat#format
rake aborted!
5 methods have a flog complexity > 30

use flog in your CI build

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

Structural similarity checking of Sexp
nodes (syntax tokens)

Fine grained duplication checking

Look for high scores (> 30)

$ 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/controllers/signups_controller.rb:16
3) Similar code found in :defn (mass = 50)
app/helpers/actions_helper.rb:43
app/helpers/actions_helper.rb:49
[More content removed...]

~/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/controllers/signups_controller.rb:16
3) Similar code found in :defn (mass = 50)
app/helpers/actions_helper.rb:43
app/helpers/actions_helper.rb:49
[More content removed...]

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

What about Rails?

1132 duplicates

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[\"sitelibdir\"]
unless $sitedir
version = CONFIG[\"MAJOR\"] + \".\" + CONFIG[\"MINOR\"]
$libdir = File.join(CONFIG[\"libdir\"], \"ruby\", version)
$sitedir = $:.find {|x| x =~ /site_ruby/ }
if !$sitedir
$sitedir = File.join($libdir, \"site_ruby\")
elsif $sitedir !~ Regexp.quote(version)
$sitedir = File.join($sitedir, version)
end
end
# the actual gruntwork
Dir.chdir(\"lib\")
Find.find(\"action_mailer\", \"action_mailer.rb\") { |f|
if f[-3..-1] == \".rb\"
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
$sitedir = CONFIG[\"sitelibdir\"]
unless $sitedir
version = CONFIG[\"MAJOR\"] + \".\" + CONFIG[\"MINOR\"]
$libdir = File.join(CONFIG[\"libdir\"], \"ruby\", version)
$sitedir = $:.find {|x| x =~ /site_ruby/ }
if !$sitedir
$sitedir = File.join($libdir, \"site_ruby\")
elsif $sitedir !~ Regexp.quote(version)
$sitedir = File.join($sitedir, version)
end
end
# the actual gruntwork
Dir.chdir(\"lib\")
Find.find(\"active_support\", \"active_support.rb\") { |f|
if f[-3..-1] == \".rb\"
File::install(f, File.join($sitedir, *f.split(/\\//)), 0644, true)
else
File::makedirs(File.join($sitedir, *f.split(/\\//)))
end
}

activerecord/install.rb
require 'rbconfig'
require 'find'
require 'ftools'
include Config
# this was adapted from rdoc's install.rb by ways of Log4r
$sitedir = CONFIG[\"sitelibdir\"]
unless $sitedir
version = CONFIG[\"MAJOR\"] + \".\" + CONFIG[\"MINOR\"]
$libdir = File.join(CONFIG[\"libdir\"], \"ruby\", version)
$sitedir = $:.find {|x| x =~ /site_ruby/ }
if !$sitedir
$sitedir = File.join($libdir, \"site_ruby\")
elsif $sitedir !~ Regexp.quote(version)
$sitedir = File.join($sitedir, version)
end
end
# the actual gruntwork
Dir.chdir(\"lib\")
Find.find(\"active_record\", \"active_record.rb\") { |f|
if f[-3..-1] == \".rb\"
File::install(f, File.join($sitedir, *f.split(/\\//)), 0644, true)
else
File::makedirs(File.join($sitedir, *f.split(/\\//)))
end
}

actionpack/install.rb
require 'rbconfig'
require 'find'
require 'ftools'
include Config
# this was adapted from rdoc's install.rb by way of Log4r
$sitedir = CONFIG[\"sitelibdir\"]
unless $sitedir
version = CONFIG[\"MAJOR\"] + \".\" + CONFIG[\"MINOR\"]
$libdir = File.join(CONFIG[\"libdir\"], \"ruby\", version)
$sitedir = $:.find {|x| x =~ /site_ruby/ }
if !$sitedir
$sitedir = File.join($libdir, \"site_ruby\")
elsif $sitedir !~ Regexp.quote(version)
$sitedir = File.join($sitedir, version)
end
end
# the actual gruntwork
Dir.chdir(\"lib\")
Find.find(\"action_controller\", \"action_controller.rb\", \"action_view\", \"action_view.rb\") { |f|
if f[-3..-1] == \".rb\"
File::install(f, File.join($sitedir, *f.split(/\\//)), 0644, true)
else
File::makedirs(File.join($sitedir, *f.split(/\\//)))
end
}

automation

lib/tasks/quality.rake
require 'flay'
desc \"Analyze for code duplication\"
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 \"#{flay.masses.size} chunks of code have a duplicate mass >
#{threshold}\" unless flay.masses.empty?
end

~/Data/runway $ rake flay
(in /Users/marty/Data/runway)
Total score (lower is better) = 164
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/controllers/signups_controller.rb:16
3) Similar code found in :defn (mass = 50)
app/helpers/actions_helper.rb:43
app/helpers/actions_helper.rb:49
rake aborted!
3 chunks of code have a duplicate mass > 25

use flay in your CI build

roodi
http://roodi.rubyforge.org/

Checks for design problems

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

Look for any errors

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

~/Data/runway $ roodi \"app/**/*.rb\"
app/models/action_format.rb:10
Method name \"format\" has a cyclomatic complexity is 12.
It should be 8 or less.
app/models/action_parser.rb:50
Block cyclomatic complexity is 11.
It should be 4 or less.
app/models/action.rb:107
Case statement is missing an else clause.
app/models/action.rb:103
Method \"apply_defaults_from_name\" has 23 lines.
It should have 20 or less.
app/controllers/application.rb:52
Found = in conditional.
It should probably be an ==

Method name \"format\" has a cyclomatic complexit
It should be 8 or less.
app/models/action_parser.rb:50
Block cyclomatic complexity is 11.
It should be 4 or less.
app/models/action.rb:107
Case statement is missing an else clause.
app/models/action.rb:103
Method \"apply_defaults_from_name\" has 23 lines.
It should have 20 or less.
app/controllers/application.rb:52
Found = in conditional.
It should probably be an ==

app/models/action_parser.rb:50
Block cyclomatic complexity is 11.
It should be 4 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

app/models/action_parser.rb:50
Block cyclomatic complexity is 11.
It should be 4 or less.
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

app/controllers/application.rb:52
Found = in conditional.
It should probably be an ==
def extract_authenticity_token
if token = request.headers[\"HTTP_X_RUNWAY_AUTHENTICITY_TOKEN\"]
params[request_forgery_protection_token] = token
end
end

What about Rails?

1996 errors

./actionpack/lib/action_controller/vendor/html-
scanner/html/node.rb:417
Method name \"match\"
cyclomatic complexity is 47.
It should be 8 or less.

def match(conditions)
conditions = validate_conditions(conditions)
# check content of child nodes
if conditions[:content]
if children.empty?
return false unless match_condition(\"\", 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 \"unknown count condition #{key}\"
end
end
end

else raise \"unknown count condition #{key}\"
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

automation

lib/tasks/quality.rake
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
(in /Users/marty/Data/runway)
app/models/action_format.rb:10 - Method name \"format\" cyclomatic
complexity is 12. It should be 10 or less.
app/models/action_parser.rb:11 - Method name \"attributes\" cyclomatic
complexity is 12. It should be 10 or less.
app/models/action_parser.rb:30 - Method name \"parse\" cyclomatic
complexity is 14. It should be 10 or less.
app/models/token.rb:173 - Method name \"parse_incubation_date\"
cyclomatic complexity is 11. It should be 10 or less.
app/models/token.rb:226 - Method name \"parse_incubation_days\"
cyclomatic complexity is 12. It should be 10 or less.
app/models/action_parser.rb:50 - Block cyclomatic complexity is 11.
It should be 8 or less.
app/models/token.rb:11 - Block cyclomatic complexity is 10. It should
be 8 or less.
app/models/action.rb:103 - Method \"apply_defaults_from_name\" has 23
lines. It should have 20 or less.
app/models/action_parser.rb:30 - Method \"parse\" has 23 lines. It
should have 20 or less.
rake aborted!
Found 9 errors.

use roodi in your CI build

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

automation

lib/tasks/quality.rake
require 'metric_fu'

$ rake metrics:all

use metrics_fu for regular
human review

Summary

lib/tasks/quality.rake (part 1)
require 'flog'
desc \"Analyze for code complexity\"
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 \"%8.1f: %s\" % [score, name]
end
raise \"#{bad_methods.size} methods have a flog complexity >
#{threshold}\" unless bad_methods.empty?
end

lib/tasks/quality.rake (part 2)
require 'flay'
desc \"Analyze for code duplication\"
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 \"#{flay.masses.size} chunks of code have a duplicate mass >
#{threshold}\" unless flay.masses.empty?
end

lib/tasks/quality.rake (part 3)
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