12 Hours To Rate A Rails Application

hours to rate a Rails application

Elise Huard @elise_huardhttp://jabberwocky.eu

Wednesday 31 March 2010

http://jabberwocky.eu


Acquisition


Maintenance


12 hours To Rate a Rails Application

12:00


Team


Team: use your gut


One man’sapplication


innovator

automator

Maintenance

Maintenance

Control Freak


...


Vision


Methodology


Bug TrackerVersion control


Back seat driver


10:00



Try the app


does it work ?


09:45



Rails version


plugins and gems



managing updatespiston

git submodules(svn externals)


Licenses


NIH syndrom


09:00



All that code


config/routes.rb

map.root :controller => 'root', :action => 'index'

map.namespace :admin do |admin| admin.resources :grids do |grid| grid.resources :nodes grid.resources :edges, :collection => {:all => :post, :update_all => :post} grid.resources :walkers end end

map.resources :nodes, :only => [:new,:create,:show,:destroy], :collection => {:directions => :put} map.resources :walkers, :only => [:show,:new,:create,:destroy], :collection => {:select => :get} map.resources :itineraries, :only => [:show]

map.four_oh_four '*path' , :controller => 'four_oh_fours'


modelsrailroad -M | dot Tpng > models.png

rubymine ctrl-alt-Duml dumper (needs maintenance)


names

“There are only two hard things in Computer Science: cache invalidation and naming things”

Phil Karlton


08:30



Coffee


metrics


Know thine tools


LOC

rake stats+----------------------+-------+-------+---------+---------+-----+-------+| Name | Lines | LOC | Classes | Methods | M/C | LOC/M |+----------------------+-------+-------+---------+---------+-----+-------+| Controllers | 2702 | 2150 | 36 | 158 | 4 | 11 || Helpers | 358 | 303 | 0 | 22 | 0 | 11 || Models | 1358 | 1104 | 30 | 117 | 3 | 7 || Libraries | 2286 | 1655 | 38 | 152 | 4 | 8 || Integration tests | 0 | 0 | 0 | 0 | 0 | 0 || Functional tests | 1687 | 1322 | 31 | 195 | 6 | 4 || Unit tests | 1356 | 1079 | 27 | 158 | 5 | 4 |+----------------------+-------+-------+---------+---------+-----+-------+| Total | 9747 | 7613 | 162 | 802 | 4 | 7 |+----------------------+-------+-------+---------+---------+-----+-------+ Code LOC: 5212 Test LOC: 2401 Code to Test Ratio: 1:0.5


RubyParser and Parsetree

Ryan Davis and Eric Hodel(‘Ruby Sadists’)


RubyParser and Parsetree

Abstract syntax treeRubyParser.new.parse(File.read(‘metrics.rb’),‘metric.rb’)

class Metrics def probe puts "good" end end

s(:class,:Metrics, nil, s(:scope, s(:defn,:probe, s(:args), s(:scope, s(:block, s(:call, nil, :puts, s(:arglist, s(:str, "good"))))))))

Symbolic Expression (Sexp)

Ruby2Ruby


flog‘the pain your

code is in’


FLOG

Weighing the AST with factorsAssignment Branch Condition (ABC) def process_if(exp) add_to_score :branch process exp.shift # cond penalize_by 0.1 do process exp.shift # true process exp.shift # false end s() end


FLOG

flog lib/flog.rb 647.8: flog total 13.8: flog/method average

87.5: Flog#output_details 58.8: Flog#process_iter 54.2: Flog#flog 48.8: Flog#parse_options 34.1: Flog#none 23.2: Flog#output_method_details 22.1: Flog#score_method 16.0: Flog#process_block_pass 15.6: Flog#report 15.2: Flog#expand_dirs_to_files 15.0: Flog#klass_name


FLOG

Very good: < 20All Right: < 50


FLAYcode similarities


RubyParser def mass @mass ||= self.structure.flatten.size end

Hash of structure of nodes with mass > threshold self.hashes[node.structural_hash] << node

analyze: if same hash = similarif same node = identical

FLAY


flay *.rb Total score (lower is better) = 621

1) IDENTICAL code found in :defn (mass*2 = 188) channel.rb:48 clip.rb:80

2) Similar code found in :defn (mass = 93) channel.rb:150 clip.rb:110 clip.rb:116

3) Similar code found in :defs (mass = 58) contact.rb:32 contact.rb:37

FLAY


Saikuroサイクロ

cyclomatic complexity


Saikuro

ruby-lex

every keyword is interpreted into ‘state’

state used to calculateif, unless, while, until, for, elsif, when, rescue

(blocks)Recursively


Saikuro


Saikuro

Good:methods < 5


RoodiRuby Object Oriented Design Inferometer (what ?)“design issues”


Roodi

RubyParservisitor pattern visitor: checker (Configurable) visitable: parsed nodes= extensible


Roodi

app/controllers/itineraries_controller.rb:4 - Method name "show" cyclomatic complexity is 14. It should be 8 or less.app/models/itinerary.rb:41 - Block cyclomatic complexity is 6. It should be 4 or less.app/controllers/itineraries_controller.rb:4 - Method "show" has 30 lines. It should have 20 or less.app/helpers/application_helper.rb:27 - Method "clippy" has 26 lines. It should have 20 or less.


Reek

Control CoupleData ClumpFeature EnvyLarge ClassLong MethodLong Parameter ListSimulated PolymorphismUncommunicative Name


http://wiki.github.com/kevinrutherford/reek/control-couple

http://wiki.github.com/kevinrutherford/reek/control-couple

http://wiki.github.com/kevinrutherford/reek/data-clump

http://wiki.github.com/kevinrutherford/reek/data-clump

http://wiki.github.com/kevinrutherford/reek/feature-envy

http://wiki.github.com/kevinrutherford/reek/feature-envy

http://wiki.github.com/kevinrutherford/reek/large-class

http://wiki.github.com/kevinrutherford/reek/large-class

http://wiki.github.com/kevinrutherford/reek/long-method

http://wiki.github.com/kevinrutherford/reek/long-method

http://wiki.github.com/kevinrutherford/reek/long-parameter-list

http://wiki.github.com/kevinrutherford/reek/long-parameter-list

http://wiki.github.com/kevinrutherford/reek/simulated-polymorphism

http://wiki.github.com/kevinrutherford/reek/simulated-polymorphism

http://wiki.github.com/kevinrutherford/reek/uncommunicative-name

http://wiki.github.com/kevinrutherford/reek/uncommunicative-name

Reek

RubyParserextends parsed nodes

traverses nodesreturns code after Ruby2Ruby


Reek

UserSessionsController has no descriptive comment (Irresponsible Module) UserSessionsController#destroy calls current_user_session twice (Duplication)app/controllers/users_controller.rb -- 5 warnings: UsersController has no descriptive comment (Irresponsible Module) UsersController tests @aid_app at least 4 times (Simulated Polymorphism) UsersController#create calls params 3 times (Duplication) UsersController#create calls params[:user] 3 times (Duplication)...


Churn

Frequent changes may indicate issue


Churn

Not only classes but also methods(RubyParser)

Version control: git, Hg, svnLocates changes in source using logs

(as in git log)


Churn

+-------------------------------------------------+---------------+| file_path | times_changed |+-------------------------------------------------+---------------+| db/schema.rb | 26 || config/routes.rb | 24 || app/controllers/application_controller.rb | 22 || app/controllers/add_apps_controller.rb | 22 || config/environment.rb | 20 || app/views/layouts/application.html.erb | 20 || app/models/ability.rb | 18 |...


Churn

common sense ... mostly useful in maintenance phase


Rcov


Rcov

Executes testkeeps track of the executed linesUsing C extension when possible

to hook into MRI

(experimental for 1.9)


Rcov

Total coverage: comments included


Rcov

good: 100% coverage


Heckle


Heckle

ParseTree + Ruby2Rubymutate

doesn’t work for ruby 1.9 (ParseTree)

time-consuming: combinatorialsmore for small programs (gems,

scripts)


Heckle

Initial tests pass. Let's rumble.

************************************************************************* AidApp#property_names loaded with 4 possible mutations**********************************************************************

4 mutations remaining...Replacing AidApp#property_names with:

--- original+++ mutation def property_names- (meta_policy and meta_policy.property_names_for(:aid_app))+ (nil and meta_policy.property_names_for(:aid_app)) end


cyclomatic complexity

size

code complexity code similarities

test coverage

antipatterns

rake stats

Flay

ReekRoodi

Flog

Saikuro

Heckle Rcov


metric_fu


06:30



Lunch


and more Coffee


read some code


Expressive code


Database

db/schema.rbseed data

everything in migrations ?


Nested_has_many_through


views

Bad:unindenteddivitisjavascript in the bodytoo much logic in viewiew


04:30



run tests


Time for tests(or autotest/ci)


maintainable test suite

tests = software

changes in implementationchanges in requirements


maintainable test suite

express code responsibilityhide incident detailDRY


02:30



Deployment


Deployment


Deployment

Automation, automation, automation


Deployment

deployment = softwaresame rules apply


Traffic


Performance testsBottlenecks


01:00



Brownie Points


Continuous integration

... and they’re using it


Documentation of any kind

... and it’s up to date


monitoringexception notification

Log analyzers


testing javascriptsContinuous performance testing


00:00



http://railroad.rubyforge.org/http://www.igvita.com/2008/12/11/ruby-ast-for-fun-and-profit/http://ruby.sadi.st/Ruby_Sadist.htmlhttp://goruco2008.confreaks.com/04_davis.htmlhttp://cwd.dhemery.com/2009/11/wmaat/http://c2.com/cgi/wiki?AbcMetrichttp://hissa.nist.gov/HHRFdata/Artifacts/ITLdoc/235/title.htmhttp://blog.rubybestpractices.com/posts/judofyr/sexp-for-rubyists.html

Elise Huard @[email protected]://jabberwocky.eu


http://railroad.rubyforge.org

http://railroad.rubyforge.org

http://www.igvita.com/2008/12/11/ruby-ast-for-fun-and-profit/

http://www.igvita.com/2008/12/11/ruby-ast-for-fun-and-profit/

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

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

http://goruco2008.confreaks.com/04_davis.html

http://goruco2008.confreaks.com/04_davis.html

http://cwd.dhemery.com/2009/11/wmaat/

http://cwd.dhemery.com/2009/11/wmaat/

http://c2.com/cgi/wiki?AbcMetric

http://c2.com/cgi/wiki?AbcMetric

http://blog.rubybestpractices.com/posts/judofyr/sexp-for-rubyists.html






Technology

12 Hours To Rate A Rails Application