Test Driven DevelopmentIt’s All about Fluency @LlewellynFalco

Is Testing Faster? (Test After)

Work (code)

Non-Work(tests)

60 Minutes

X minutes

Code60 Minutes< Code + Test

60 + X minutes

Is Testing Faster? (Test 1st)

Work (code)

Non-Work(tests)

30 Minutes

X minutes

Code60 Minutes < Test + Code

X + 30 minutes?

Today’s Kata: Triangle1) A side has a distance2) Side knows endpoints3) 3 points4) 3 sides5) Perimeter6) Get sides touching a point7) Get side opposite a point8) The angle of 2 sides touching a point9) 3 angles10) Right Triangle

Parts of a Test

1) Do2) Verify

Demo

Benefits of Unit Tests

1) Specification2) Feedback3) Regression4) Granularity

Regression

If I used to get : Then I still get :

AA

Intentional Code

// Create a Side from (0,0) to (5,0)

var side = new Side(0,0,5,0);

Consume 1st

Write the objects & methods you wish existed

Test Until Bored

Test the cases that bring you value

VerificationIs it the right answer?1. Change the Question2. Ask an expert

Completing the CircleYour output should tell the story.Objects should have ToStrings

Benefits1. Specification2. Feedback3. Regression4. Granularity

Fake it Till You Make ItBuys some timeAllows for Triangulation

Today’s Kata: Triangle1) A side has a distance2) Side knows endpoints3) 3 points4) 3 sides5) Perimeter6) Get sides touching a point7) Get side opposite a point8) The angle of 2 sides touching a point9) 3 angles10) Right Triangle

Verifying MultiplesVerify Single:Approvals.Approve(result);

Verify Many:Approvals.Approve(results, "label");

Multiple Cases

Approvals.Approve(cases, c => TestWith(c));

Maintaining TestsSame Quality as Production Code

ResourcesTest Driven Development: By Example

Kent Beck

Resourceswww.ApprovalTests.com

Resources

Intro To TDD Class (4 Day)Legacy Code

www.Develop.com

TeachingKidsProgramming.orgDo a Recipe Teach a Kid (Ages 10 ++)Microsoft SmallBasic Free Courseware (recipes)

Please fill out evaluations:TDD – Fluency #AT11

@LlewellynFalcohttp://LlewellynFalco.Blogspot.comhttp://www.approvaltests.com @ArloBelshee

(Microsoft)http://www.arlobelshee.com