TEST DRIVEN DEVELOPMENT

Let’s begin →Let’s begin →

At 10,000 feet

WHY TDD?

• We need a way to find defects earlier on in the development cycle..

TDD REDUCES DEBUG TIME

TESTS = CODE EXAMPLES

NO TDD = NO VELOCITY• The more complex our code becomes, the longer it takes to make

changes or add new features.C

ompl

exity

Time Easy to change

Hard to change

TDD PROTECTS US FROM OURSELVES

• Automated tests remind us when we inadvertently screw up part of the code. No matter how significant.

TDD EMPOWERS YOU

THE THREE RULES OF TDD

RULE # 1

• You are not allowed to write any production code unless it is to make failing unit tests pass.

RULE #2

• You are not allowed to write any more of a unit test than is sufficient to fail; and compilation failures are failures.

RULE #3

• You are not allowed to write any more production code than is sufficient to pass the one failing test.

TDD IN PRACTICE

SAY WHAT?

Let’s see some code

The Bowling Game

1

60

4

5

4 5

14

6 5

29 49

0 1

11761

7 6

77 97

2 6

133

• Test code is just as important as production code and should be shown the same level of respect and professionalism.

THANK YOU!Any Questions?