Testing Para Vagos

 

A brief introduction

 

"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

  1. Set Up
  2. Exercise
  3. Verify
  4. TearDown

What we need?

  1. Runner
    • ​Execution
    • Reporting
  2. 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)

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

Thanks!!!!!

Q&A

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