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If you had an opportunity to build an application from the ground up, with testability a key design goal, what would you do? In this presentation, we will look at just such a situation - a major, two year rewrite of a suite of core business systems. We will discuss how a system looks when testability is as important as functionality - and what it looks like when quality concerns are part of the initial design. We will look at the role of test automation and manual test in a modern project, and look at the tools and processes. The session will conclude with a demo of the latest visual test automation tool from MIT and a Q&A.
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Design for Testability
Will Iverson
Who Is This Guy? Will Iverson
[email protected] Check www.nukio.com for LinkedIn, Twitter, etc.
Java since 1995 Pascal/C/C++ before that… Apple, Symantec, Sun, BEA…
Four books on Java Hibernate, Web Services, Mac OS X Java, Jakarta Commons
Today: Architect, Consultant, Manager, Coach All Star Directories, Architect Nukio, Coach/Trainer/Consultant
Audience Qs Java, .NET, Other…? Agile, Waterfall, Other…? Who is your customer?
Basic Premise Design should include:
Correctness Performance Usability Testability
Why Design Testability? Care about quality of work Want rapid feedback Want to solve problem correctly Want to be able to make changes without fear Want to be a team working toward same goals!
What is Design? Design : planning that lays the basis for making of every
object or system Both a noun & verb
Things you design… Database models System components User interfaces Process for adding features & fixing issues
Typical Web App Development Flow Current Software • Validate (customer, market, product management, etc.)
New Feature or Fix • What does it do?
Design • Database changes • Code
Implement • Database changes • Code
Test • Verify against requirements • Negative tests
Deploy • Validate non-functional (perf, system)
Design for Testability Current Software • Validate (customer, market,
product management, etc.)
New Feature or Fix • What does it do?
Design • Tests • Database changes • Code
Implement • Tests • Database changes • Code
Deploy • Validate non-functional (perf,
system)
How you test & what you test informs the design!
Agile, Waterfall, Other…? Agile
Test Driven Development, Behavior Driven Development, Acceptance Test Driven Development
Reality check: team dynamic?
Waterfall Typical: QA handed requirements, software: figure it out Lucky: QA test plan is included in initial sign off
Freeform Sit in the same room, hash it out daily
Sample: Code Centric High Level Stack
Presentation • External Web Site (Spring MVC) • Internal Tools (Grails) • Partner API (XML via HTTPS) • Reporting (Jasper)
Business Logic • Spring • Hibernate
Database • Data Model • Data Set[s]
Example: Testable High Level Stack Design
Presentation • External Web Site (Spring MVC) • Internal Tools (Grails) • Partner API (XML via HTTPS) • Reporting (Jasper)
Business Logic • Spring • Hibernate
Database • Data Model • Data Set[s]
Spring Controller Tests Canoo Web Tests Selenium HTMLUnit Report Monitoring Job[s]
JUnit DbUnit Mockito (external services)
p6spy Jailer LiquiBase
How would I test and identify the resolution to any open issues?
Sample: Typical Model Design “There are two ways of
constructing a software design. One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies.” C.A.R. Hoare
Testable Model Design
Lead Generation Service
• 3 public interface methods
Lead Delivery Service
• 4 public interface methods
Revenue Recognition
Service • 6 public interface methods
Test this independently of everything else
Complexity Kills Services Stateless interfaces
Avoid complex choreography Single request/response actions
More than 5-8 tables? More than 5-8 classes? Break it up
But… it’s not complicated enough!? Exactly.
What about Integration Tests? Are you testing integration, or are you testing coupled
components Coupled components = revisit design!
Real World Examples: Decoupling By Force
OS & Application Processes Database Connection Recovery Virtual Machines (Java, .NET, VMWare, etc)
“Chernobyl-Based Design”
Test at the Right Place Don’t test your database through the GUI Don’t test your business logic through the GUI You can’t test APIs (remote/distributed or traditional) via
GUI
Common Challenges JavaScript
You can test JavaScript via Selenium if properly implemented Takes work & discipline
Bad HTML Test: can you push back on dev to get proper ids?
Layout & Design Fidelity Browsershots Many hosted services
Things To Mock Clock 3rd Party Services
What about database interaction?
Things To Do Someone needs to do exploratory testing
QA background is key
Someone needs to automate the testing Avoid manual regression – oh, the humanity!
Someone needs to validate with the customer Acceptance tests?
Shameless Plug Agile Testing
CI, TDD Expert JUnit DBUnit, HTMLUnit, Selenium Automate documentation generation
March 25th – 26th
www.nukio.com
Bonus Finale: Sikuli
Q & A
