Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Writing readable tests
Search
Alex Tercete
August 20, 2015
Programming
2
190
Writing readable tests
Lightning Talk presented at the LSCC Talks #14 event.
Alex Tercete
August 20, 2015
Tweet
Share
More Decks by Alex Tercete
See All by Alex Tercete
Making Makefiles
alextercete
0
83
Shipping containers
alextercete
0
68
Parallelism and Symmetry
alextercete
0
230
Porting to .NET Standard
alextercete
0
69
Prepping Commits
alextercete
1
140
The end of your line-endings nightmare
alextercete
0
200
I love sushi, therefore I love rebase
alextercete
0
110
ReadyRoll for DotNet developers
alextercete
0
96
Coding Dojo: The Randori Kata
alextercete
1
550
Other Decks in Programming
See All in Programming
Google I/O Extended Incheon 2025 ~ What's new in Android development tools
pluu
1
220
ご注文の差分はこちらですか? 〜 AWS CDK のいろいろな差分検出と安全なデプロイ
konokenj
5
750
Workers を定期実行する方法は一つじゃない
rokuosan
0
140
テスターからテストエンジニアへ ~新米テストエンジニアが歩んだ9ヶ月振り返り~
non0113
2
250
Git Sync を超える!OSS で実現する CDK Pull 型デプロイ / Deploying CDK with PipeCD in Pull-style
tkikuc
4
510
可変性を制する設計: 構造と振る舞いから考える概念モデリングとその実装
a_suenami
10
1.4k
kiroでゲームを作ってみた
iriikeita
0
130
顧客の画像データをテラバイト単位で配信する 画像サーバを WebP にした際に起こった課題と その対応策 ~継続的な取り組みを添えて~
takutakahashi
4
1.4k
構造化・自動化・ガードレール - Vibe Coding実践記 -
tonegawa07
0
170
Flutterと Vibe Coding で個人開発!
hyshu
1
210
React は次の10年を生き残れるか:3つのトレンドから考える
oukayuka
41
16k
SQLアンチパターン第2版 データベースプログラミングで陥りがちな失敗とその対策 / Intro to SQL Antipatterns 2nd
twada
PRO
36
11k
Featured
See All Featured
Fight the Zombie Pattern Library - RWD Summit 2016
marcelosomers
234
17k
Design and Strategy: How to Deal with People Who Don’t "Get" Design
morganepeng
130
19k
10 Git Anti Patterns You Should be Aware of
lemiorhan
PRO
656
60k
CSS Pre-Processors: Stylus, Less & Sass
bermonpainter
357
30k
The Straight Up "How To Draw Better" Workshop
denniskardys
235
140k
Become a Pro
speakerdeck
PRO
29
5.5k
Unsuck your backbone
ammeep
671
58k
The World Runs on Bad Software
bkeepers
PRO
70
11k
Music & Morning Musume
bryan
46
6.7k
VelocityConf: Rendering Performance Case Studies
addyosmani
332
24k
What's in a price? How to price your products and services
michaelherold
246
12k
Imperfection Machines: The Place of Print at Facebook
scottboms
267
13k
Transcript
Writing readable tests Separating mechanics from data Alex Tercete @alextercete
https://www.flickr.com/photos/vdepizzol/8081618546
read- ability?
read- ability
understand- ability
The four elements of readability
https://www.flickr.com/photos/tychosnose/15416119182 Context WHERE
Reader’s Experience https://www.flickr.com/photos/theilr/5048464567 WHO
https://www.flickr.com/photos/thomasclaveirole/463202335 Structure HOW
Content https://www.flickr.com/photos/carinefel/13916816466 WHAT
Structure Mechanics Content Data
https://www.flickr.com/photos/emily3333000/16210254212
[Test] public void Add_two_numbers() { var calculator = new RpnCalculator();
calculator.Push(5); calculator.Push(3); Assert.That(calculator.Add(), Is.EqualTo(8)); } [Test] public void Add_two_numbers() { var calculator = new RpnCalculator(); calculator.Push(5); calculator.Push(3); Assert.That(calculator.Add(), Is.EqualTo(8)); }
[Test] public void Subtract_two_numbers() { var calculator = new RpnCalculator();
calculator.Push(5); calculator.Push(3); Assert.That(calculator.Subtract(), Is.EqualTo(2)); } [Test] public void Add_two_numbers() { var calculator = new RpnCalculator(); calculator.Push(5); calculator.Push(3); Assert.That(calculator.Add(), Is.EqualTo(8)); } [Test] public void Subtract_two_numbers() { var calculator = new RpnCalculator(); calculator.Push(5); calculator.Push(3); Assert.That(calculator.Subtract(), Is.EqualTo(2)); }
Don’t Repeat Yourself
[SetUp] public void SetUp() { _calculator = new RpnCalculator(); _calculator.Push(5);
_calculator.Push(3); } [Test] public void Add_two_numbers() { Assert.That(_calculator.Add(), Is.EqualTo(8)); } private RpnCalculator _calculator; [SetUp] public void SetUp() { _calculator = new RpnCalculator(); _calculator.Push(5); _calculator.Push(3); } [Test] public void Add_two_numbers() { Assert.That(_calculator.Add(), Is.EqualTo(8)); } [Test] public void Subtract_two_numbers() { Assert.That(_calculator.Subtract(), Is.EqualTo(2)); }
Repeat everything
[Test] public void Add_two_numbers() { var calculator = new RpnCalculator();
calculator.Push(5); calculator.Push(3); Assert.That(calculator.Add(), Is.EqualTo(8)); } [Test] public void Subtract_two_numbers() { var calculator = new RpnCalculator(); calculator.Push(5); calculator.Push(3); Assert.That(calculator.Subtract(), Is.EqualTo(2)); } [Test] public void Add_two_numbers() { var calculator = new RpnCalculator(); calculator.Push(5); calculator.Push(3); Assert.That(calculator.Add(), Is.EqualTo(8)); }
Separate mechanics from data
public void SetUp() { _calculator = new RpnCalculator(); } [Test]
public void Add_two_numbers() { _calculator.Push(5); _calculator.Push(3); Assert.That(_calculator.Add(), Is.EqualTo(8)); } private RpnCalculator _calculator; [SetUp] public void SetUp() { _calculator = new RpnCalculator(); } [Test] public void Add_two_numbers() { _calculator.Push(5); _calculator.Push(3); Assert.That(_calculator.Add(), Is.EqualTo(8)); } [Test] public void Subtract_two_numbers() { _calculator.Push(5); _calculator.Push(3); Assert.That(_calculator.Subtract(), Is.EqualTo(2)); }
If it isn’t data, it must be mechanics https://www.flickr.com/photos/sarahreido/3120877348
[Test] public void Show_result_of_an_addition_on_the_display() { var stubCalculatorEngine = Substitute.For<ICalculatorEngine>(); stubCalculatorEngine.Add(1,
2).Returns(3); var mockCalculatorDisplay = Substitute.For<ICalculatorDisplay>(); var calculator = new Calculator(stubCalculatorEngine, mockCalculatorDisplay); calculator.Type('1', '+', '2', '='); mockCalculatorDisplay.Received().Show("3"); }
[Test] public void Show_result_of_an_addition_on_the_display() { var stubCalculatorEngine = Substitute.For<ICalculatorEngine>(); stubCalculatorEngine.Add(1,
2).Returns(3); var mockCalculatorDisplay = Substitute.For<ICalculatorDisplay>(); var calculator = new Calculator(stubCalculatorEngine, mockCalculatorDisplay); calculator.Type('1', '+', '2', '='); mockCalculatorDisplay.Received().Show("3"); }
[SetUp] public void SetUp() { _stubCalculatorEngine = Substitute.For<ICalculatorEngine>(); _mockCalculatorDisplay =
Substitute.For<ICalculatorDisplay>(); _calculator = new Calculator(_stubCalculatorEngine, _mockCalculatorDisplay); } [Test] public void Show_result_of_an_addition_on_the_display() { _stubCalculatorEngine.Add(1, 2).Returns(3); _calculator.Type('1', '+', '2', '='); _mockCalculatorDisplay.Received().Show("3"); }
Keep only what is essential to understand the test
Thanks! Alex Tercete @alextercete https://speakerdeck.com/alextercete/writing-readable-tests