Embed Size (px)
Citation preview
BEYOND HACKINGCrafting Quality Software
HOW IS SOFTWARE BUILT IN SMALL TEAMS?
WHY DOES THAT APPROACH NOT SCALE?
WHAT IS QUALITY?
HOW CAN WE ACCOMPLISH IT?
FROM CLEAN CODE - A HANDBOOK OF AGILE SOFTWARE CRAFTMANSHIP BY ROBERT C. MARTIN
Development Speed
Issues
WHAT IS QUALITY?
BUILDING SOFTWARE IN SMALL TEAMS
App
1. Code
2. Deploy
<Code>
V 1.0 V 1.0.1 V 1.1 V 1.1.1
Add FeatureFix Bug Fix Bug
LIFE IS SIMPLE LIFE IS GOOD
YOU ARE SHIPPING FAST
BUT SOMETHING FEELS WRONG
def update(post, title) @user = User.first
if @user.logged_in if @user.type == "admin" @user.type.permissions.each do |permission| { if (permission == "update_permission") { if post begin post.title = title post.save rescue display_error("This horrible code is not workin!") end else display_error("No Post provided") end } } elsif @user.type == "other" return else display_error("Invalid User Type") end else #What do here? end end
BAD CODE
TEAMS GROW, SOFTWARE GROWS
Rock Bottom
t
code complexitydev velocityissues
App
1. Code
2. Deploy
<Code>
?
?
!
!
!
?
?
!
WHAT NOW?
IT’S TIME TO REFACTOR
WHERE’S THE SPEC FOR ALL FEATURES?
…
HOW CAN WE AVOID THIS?
AS SOFTWARE AND TEAM GROW - ADD PROCESS
AND AUTOMATION
HOW CAN WE AVOID CHAOS?
Specification
Automated Testing
Continous Integration
Coding guidelines / Code Analysis
Reproducible development environment
(1) SPECIFY YOUR APPLICATION
TESTS CAN ACT AS SPECIFICATION!
BDD FRAMEWORKS CAN BE USED TO SPECIFY SOFTWARE
Cucumber Framework: http://cukes.info/
Feature: Search courses Courses should be searchable by topic Search results should provide the course code
Scenario: Search by topic Given there are 240 courses which do not have the topic "biology" And there are 2 courses, A001 and B205, that each have "biology" as one of the topics When I search for "biology" Then I should see the following courses: | Course code | | A001 | | B205 | Acceptance Test
(2) WRITE AUTOMATED TESTS (BEFORE WRITING APPLICATION CODE)
HOW SHOULD WE TEST?
ACCEPTANCE TEST
When it fails, it tells you that the application is not doing what the
customer expects it to do
UNIT TEST
When it fails, it tells you what piece of your code needs to be fixed
EXAMPLE
SignupService.POST(User:"Ben-G", PW:"&47-:#sdö").expect(200) SignupService.POST(User:"Ben-G", PW:”").expect(400)
SignupService.POST(User:"Ben-G", PW:"&47-:#sdö").expect(200)
PasswordValidator.testPassword("&47-:#sdö").expect(true) PasswordValidator.testPassword(“”).expect(false)
UsernameValidator.testUsername("Ben-G").expect(true)
PasswordValidator
SignupService
testPassword:Bool
HTTP POST User: Ben-G
PW: &47-:#sdö
UsernameValidator
testUsername:Bool
SignupService.POST(User:"", PW:"&47-:#sdö").expect(401) UsernameValidator.testUsername("").expect(false)
Acceptance Tests Unit Tests
(3) MEASURE CODE COVERAGE
CODE COVERAGE = % OF CODE COVERED BY TEST
(4) PROVIDE CODING
STYLEGUIDES, AUTOMATE CODE QUALITY TESTING
RUBOCOP, OCLINT, JSLINT TOOLS THAT MEASURE CONFORMANCE TO CODING GUIDELINES + FIND CODE SMELLS
“static analyzers”
CODE CLIMATE
STATIC ANALYZER AS
A SERVICE
(5) USE A CONTINUOUS
INTEGRATION SERVER
CONTINOUS INTEGRATION Every time code is pushed: • Run Static Analyzer • Run All tests • Measure Code Coverage • Run the Build Process
Working product can be shipped at any time!If anything breaks we find out right away
(6) PROVIDE REPRODUCIBLE
DEVELOPMENT ENVIRONMENT
?
But it works on my local machine…
MINIMUM CONFIGURATIONgit clone [email protected]:MakeGamesWithUs/www-makeschool.git
./server start
./server test
start rails serverrun test suite
• Git repository contains the definition of a Docker container+ a Fig configuration describing services
• App runs in Virtual Machine providing the same environment for all developers
+VM
define
Rails App
MongoDB
Postgres
PUTTING IT ALL TOGETHER
Code Coverage Measurements
Unit Tests
enforce
Acceptance Tests
Specification
Low Issue Count
define
support
Refactoring
enable
High Code Qualitydrives
enables
Automated CodeQuality Analysis
drives
drives
Development Speed
Reproducible DevelopmentEnvironment
drives
enables
support
ContinousIntegration{
automates
QUALITY SOFTWARE =
SLEEP WELL AFTER PUSHING NEW CODE TO MILLIONS OF USERS
QUALITY SOFTWARE
t
code complexitydev velocityissues
