"I get paid for code that works, not for tests, so my philosophy is to test as little as possible to reach a given level of confidence …"

Kent Beck

No silver bullets

What is testing about?

Getting feedback,
as much frequent as we can

the sooner, the better

Taxonomy

Small

Medium

Large

Test by Scope

Unit Tests

Dependency Injection

Dependency:
A depends on B when A needs B to do its job
Injection:
Oject which uses (creates) A tells A who is B

Dependency Injection

VS

Test doubles

Test doubles (Fake)

Fake implenmentation just to make test pass

Test doubles (Stub)

Stubs provide canned answers to calls made during the test, usually not responding at all to anything outside what’s programmed in for the test.

Ruby (rspec)

Javascript (sinon)

Test doubles (Spy)

Spies are objects that also record some information based on how they were called

Test doubles (Mock)

Informal: think in a Stub which is also a Spy.
It also responds with default values to non-explicitly declared methods

PHP (phpunit)

Ruby (rspec-mock)

Javascript (sinon)

Integration test which want to be a unit test

FIRST(it)

Fast
Hundred or thousands per second
Isolates
Failure reasons become obvious
Repeatable
Any order, any time
Self-validating
No manual execution required
Timely
Written before code
Inmutable*
SUT is in the same state after execute the tests
Trusted*
When test fails is because the system fails and viceversa

3

Integration test which works with external system

Integration test which uses the UI

System Test

Who, when and where run the tests?

Unit
- Owner: developer
- When: after every change
- Where: every computer
Integration
- Owner: developer || QA team
- When: as part or after commit stage
- Where: devel and pre-pro environments
System
- Owner: QA team
- When: as part or after commit stage
- Where: devel and pre-pro environments

Automatic Testing

4 phases-tests

Set Up
Exercise
Verify
TearDown

What we need?

Runner
- Execution
- Reporting
Assertion framework

Testing framewok families

X-Unit
- @Before(Class)
- @Test
- @After(Class)
Rspec
- describe
  - beforeEach
  - it
  - afterEach
Specification by example (aka BDD)
- Given
- When
- Then

XUnit

Java (Junit)

PHP (phpUnit)

RSpec (suite per class)

Node/Javascript (mocha/jasmine)

Ruby (rspec)

RSpec (suite per setup)

BDD (specification)

Ruby (cucumber)

Java (cucumber)

TIPS & TRICKS

Questions & Stupid Questions

¿Where I place my tests?
¿Who tests the classes which test our classes?
¿Could you be able to rewrite the code only reading the tests definitions?
I spend more time writing code to setup my SUT than writing the test, how do you solve it?
¿What is the minimum coverage should I expect for my code?
I’ve never write a test ¿where can I start?
My code is not testable at all, ¿what can I do?
How do I run my tests?

¿Where I place my tests?

Unit tests:
- Test Class per Class
- Test Class per SetUp (useful in Xunit frameworks)
- Important naming convention (<ClassName>Test, <TestSuite>IntegrationTest, …)
System tests:
- Different project

¿Where I place my tests?

Java Project (Test Class per Class)
MyProject/
src/
main/
java/
com.groupId.artifactId.MyClass.java
resources/
test/
java/
com.groupId.artifactId.MyClassTest.java
com.groupId.artifactId.it.suite.MyTestCaseIntegrationTest.java
resources/

Java Project (Class per SetUp)
MyProject/
src/
main/
…
test/
java/
com.groupId.artifactId.myclass.<SetUp1>Test.java
com.groupId.artifactId.myclass.<SetUp2>Test.java
…

¿Where I place my tests?

Android Project
MyProject/
AndroidManifest.xml
res/
... (resources for main application)
src/
... (source code for main application) ...
tests/
AndroidManifest.xml
res/
... (resources for tests)
src/
... (source code for tests)

NodeJs Project
MyProject/
lib/
myClass.js
main.js
test/
ut/
/suite
it/
lib/
myClassTest.js

IOS Project
MyIOSProject/
MyIOSProject/
... app code ...
MyIOSProjectTests/
... test code ...

¿Who tests the classes which test our classes?

Exactly, this is why it's so important our tests follow

KISS

¿Could you be able to rewrite the code only reading the tests definitions?

Tests, specially Black Box tests, should tell us an story

Well defined and complete scenarios for Acceptance Tests

2

I spend more time writing code to setup my SUT than writing tests. How do you solve it?

Read about fixtures (XUNIT Patterns is a good reference)
- Fresh fixtures
- Shared fixtures
- Persistent fixtures

1

I duplicate too much code on objects creation, mocks definition and assertions

Writing a lot of code to initialize value objects?
- Create MotherObjects/DataBuilders

Writing a lot of code to initialize mock/stub objects?
- Create MockMotherObjects/MockBuilders
Writing a lot of asserts (more purist says only one assertion)?
- Create CustomAsserts

3

I’ve never write a test ¿where can I start?

My code is not testable at all,

what can I do?

First of all, go to http://refactoring.com/
I suggest:
1. Add integration regression test.
2. Remove new from methods and ad it to constructors (this will prepare your class for dependency injection).
3. Creates a constructor which receive every dependency your class will need.
4. Remove static classes and methods (adding the new non-static as a class dependency).
5. Add as much tests as you want to ;)

Important!!! Do it step by step

3

How do I run my tests?

Java / Android
- $ mvn test
- $ gradle test
Ruby
- $ rake test
Php
- $ phpunit <testFolder/File>
NodeJs
- $ npm test
- $ grunt test
Javascript
- $ karma start

Testing Para Vagos

KISS

I’ve never write a test ¿where can I start?

My code is not testable at all,

what can I do?

How do I run my tests?

Q&A

Testing Para Vagos

Testing Para Vagos

Sergio Arroyo

Testing Para Vagos

KISS

I’ve never write a test ¿where can I start?

My code is not testable at all,

what can I do?

How do I run my tests?

Q&A

Testing Para Vagos

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