Transcript
Trainer’s profile
Over seven years experienced in software industry on both product development and out-sourcing.
Hand-over various positions from developers, technical lead, project manager, technical architecture and program/product managers.
Trainer’s profile (cont.)
Be experienced in managing small, medium and large projects/program – Took oversight more than 100 associates in one of the biggest account in company
Be experienced on technical design, technical management in various sizes of projects from small to enterprise applications on both desktop and web environment
Trainer’s profile
Be recognized as an Agile expert that has experienced in managing Agile process, applying Agile practices.
Maintain the blog that share experienced in software development on both technical and management areas (http://www.haiphucnguyen.net/blog/)
Unit test - FAQs
Check the link for some common concerns of applying unit test and its benefits: http://www.haiphucnguyen.net/blog/?p=40
Unit test best practices
Keep test method as simple as possible:– DRY principle (Don’t repeat yourself)– Re-use test set up across test cases: put non-
trivial test data in test set up method– Clean test code as productive code
Evident data All non-trivial methods must be passed unit
test with 100% coverage ratio.
Unit test best practices
Unit test independent with:– Other unit tests, order of unit test running– Environment (operating system, hardware
configuration, database …) Fix broken test as soon as possible (it should
be immediately) After fixing defect, write unit test to prevent it
re-occur
Unit test best practices
All test cases must be passed at the end of working day.
Test project code, not library code Minimal maintenance of test code If you can not write unit test for some
functionality that means your code has problem! Refactor it immediately
How to make code becomes testable
Using interface in communication among layers, modules.
Dependency injection Dependency lookup Methods/Constructors has as less
parameters as possible (4 is the best number)
How to make code becomes testable
Class is not depended in many other classes -> it is hard to initiate instance of this class
One method has only one purpose Be careful with singleton class or static
methods! And the most important: refactoring your
code if it is not testable (esp. legacy code)
Refactoring
Refactoring is a disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior. The system is also kept fully working after each small refactoring, reducing the chances that a system can get seriously broken during the restructuring.
Refactoring (cont.)
Whenever you think you can make more benefits with your new code:– Increase the re-usability– Make the code becomes testable– Avoid the rigid, fragile issues– Better performance– …
Refactoring – best practices
Keep small change running before proceed another change.
Unit test should be written to make sure refactoring does not change system’s behaviors.
To legacy system: write test first, refactoring and verify result
Test Driven Development
TDD is a technique to improve the quality of both code and design. Developers will write the test first, then writing the code to make it pass the test. They can refactor code to avoid issues (duplication or non-optimize code …)
TDD benefits
Promoting high code coverage for productive code.
Improving quality of architecture and code Prevent defects cost is less than detect
defects cost
TDD Cycle
Prepare a list of test cases Follow the TDD Rhythm:
– Pick a test to implement– Write a fail test– Quickly make test green– Refactor to eliminate duplication
TDD – Things always do
Write test-first Maintain to-do list Writing new code only if there is failing
automated test Run all tests all the time not only single
isolated test
TDD – Things never do
Write test for trivial methods (such as getters/setters)
Commit code with failed test Big upfront design and code that makes test
first do not cover all cases of writing code
TDD best practices
Write the simple test first, then write code. After that write test code for more complexity functionality
Run test immediately whenever complete writing code
If spending much time for writing code, break the functionality into smaller ones and applying TDD for these pieces
TDD best practices
Whenever test code or productive code smells, refactor it immediately
After writing code, use coverage tool to make sure productive code is covered 100% by test method. If some piece of code is not covered, your implementation has problem!
Use mock objects if needed
Tools support TDD
Various tools help developers easier to do TDD:– IDE: Eclipse, MS Visual Studio Team System– Build tools: Ant, Maven, Nant– xUnit tools: Junit, TestNG, DBUnit, Nunit, …– Coverage tools: JCoverage, NCoverage
TDD examples
A user story of login page:– Presentation Layer: Login.html, Login.java– Service Layer: LoginService.java– Data Access Layer: LoginDAO.java
More complex user story: applying acegi for authentication – authorization process:– Re-factor LoginService.java– Run test again
TDD examples (cont.)
Write the mock up html file: Login.html Write test class: LoginTest.java Write test method for case user login
success:@TestPublic void testLoginSuccess() { ….}
TDD examples (cont.)
Implement login function that pass the testVoid onSubmit() { if (username.equals(“VietNam”)) { setResponsePage(Helloworld.class); } else { form.error(“Login fail”); }}
TDD examples (cont.)
Run LoginTest again and verify result (it has green color)
Return the Login.java and add feature verifying user base on databaseVoid onSubmit() { if (userService.getUser(userName) != null) { … }}
TDD examples (cont.)
The enterprise application that maintains the suite of test cases and number of test cases is growing daily:– Automation unit test– Continuous Integration
top related