Testing Talk

This is about automated testing, for PHP.

Everyone is testing already, by hand. This involves:

• Unit testing
• Functional testing
• Acceptance testing
• Browser testing
• …

All of the above is already done by you, so … NO PANIC!

This is "The Hitchhiker's Guide to […]" testing.

Table of contents:

local

Start

Execute the following:

git clone https://github.com/DanielSiepmann/testing-talk.git
cd testing-talk

Clean everything:

git clean -dfx

Installation development dependencies using composer:

composer install

This also includes PHPUnit, see: composer.json

Check installation:

./vendor/bin/phpunit --version

This would not work yet, as we do not have any tests:

./vendor/bin/phpunit Tests/Unit/

Links:

• https://phpunit.de/
• https://packagist.org/packages/phpunit/phpunit

Note

The concrete PHPUnit version also depends on your current PHP Version.

Create first test

Hands on! Let's write a first basic test.

E.g. a small model with a bit logic:

mkdir -p Tests/Unit/Domain/Model
cp Resources/Private/CodeExamples/Tests/Unit/Domain/Model/AddressTest.php \
   Tests/Unit/Domain/Model/AddressTest.php

Execute the first test:

./vendor/bin/phpunit Tests/Unit/

Execute with colors:

./vendor/bin/phpunit --color Tests/Unit/

Execute with info about executed tests:

./vendor/bin/phpunit --color --debug Tests/Unit/

What's in the test?

1. We have one PHP class AddressTest.
2. The class and file ends with Test.
3. Two public methods.
4. The methods are annotated with @test.
5. Methods create an instance of the class to test.
6. Methods call an assert*() method.

Create test for controller

Introduction to mocking

What is mocking, or a mock?

In object-oriented programming, mock objects are simulated objects that mimic the behavior of real objects in controlled ways.

A programmer typically creates a mock object to test the behavior of some other object, in much the same way that a car designer uses a crash test dummy to simulate the dynamic behavior of a human in vehicle impacts.

— https://en.wikipedia.org/wiki/Mock_object

• https://phpunit.de/manual/6.5/en/test-doubles.html
• https://en.wikipedia.org/wiki/Mock_object

Add the test

We want to test the controller now:

mkdir -p Tests/Unit/Controller
cp Resources/Private/CodeExamples/Tests/Unit/Controller/FrontendUserControllerTest.php \
   Tests/Unit/Controller

Execute all tests:

./vendor/bin/phpunit --color Tests/Unit/

Alternative output

testdox

Used as "agile" output:

./vendor/bin/phpunit Tests/Unit/ --color --testdox-html Results/testdox.html
xdg-open Results/testdox.html

xml

Used in CI to parse results:

./vendor/bin/phpunit --log-junit Results/junit.xml Tests/Unit

html Coverage

Used to check which methods still need testing:

./vendor/bin/phpunit --coverage-html Results/Coverage/ --whitelist Classes Tests/Unit
xdg-open Results/Coverage/index.html

Benefits of tests

1. Detect new bugs.
2. Reproduce bug.
3. Speed up development.
4. Make sure the same bug does not occur a 2nd time.
5. Show how to use the written code.
6. Allow co-worker, in pull request, to see what you expect. And how you understood the feature-request.
7. Write code without working system, by using tests instead.
8. Allow more secure refactoring.
9. Forces to write clean code.

Automate test execution

Existing tests are great. If they are executed.

Tests which exist are code, if they are not executed, they are dead code.

Tests costs money, so get the money back by executing tests.

The easiest way is to have an CI (=Continuous Integration).

E.g.:

• Jenkins
• Travis
• GitLab CI
• Bitbucket Pipelines
• Bamboo
• Circle CI
• …

See: https://awesomelists.top/#/repos/ciandcd/awesome-ciandcd

Use `phpunit.xml.dist`:

cp Resources/Private/Configs/phpunit.xml.dist phpunit.xml.dist

./vendor/bin/phpunit

Metrics

Code Coverage

Most of the time counts only number of executed lines.

This helps to find untested code, nothing more! 100% covered lines does not mean you are testing all circumstances, just every line at least once.

E.g.:

<?php

    if ($var1 || $var2) {
        echo 'test';
    }

?>

Will have 100% if all lines are executed, that is even if we do not provide $var2. We have to test the possible cases, not only all lines.

• https://stackoverflow.com/a/90021/1888377
• https://www.martinfowler.com/bliki/TestCoverage.html
• https://phpunit.de/manual/6.5/en/code-coverage-analysis.html

Crap

Is not:

https://img.devrant.com/devrant/rant/r_1046201_T68wf.jpg

— https://devrant.com/search?term=code+reviews

Is: change risk anti pattern score

Combines complexity and test coverage.

Different kinds of tests

• https://stackoverflow.com/a/4145576/1888377
• http://www.getlaura.com/testing-unit-vs-integration-vs-regression-vs-acceptance/
• https://en.wikipedia.org/wiki/Category:Software_testing Lists: Acid tests, Unit testing, A/B testing, Acceptance testing, Ad hoc testing, Agile testing, All-pairs testing, API testing, Black-box testing & White-box testing, Boundary testing, Cloud testing, Compatibility testing, Component-based usability testing, …

Unit Tests

What we did above. White box test of small pieces of code.

Functional Tests

Involves multiple code parts, database, file system and further components, e.g. web server.

Acceptance Tests

Tests from user view, e.g. via browser.

Mutation testing

Tests how easy it is to break test.

• https://infection.github.io/
• https://infection.github.io/guide/mutators.html
• https://en.wikipedia.org/wiki/Mutation_testing

Summary

Start writing tests, small unit tests.

Automate execution of tests.

Improve.

Further reading

• https://github.com/DanielSiepmann/testing-talk/tree/develop
• https://phpunit.de/
• https://awesomelists.top/#repos/ziadoz/awesome-php
• https://en.wikipedia.org/wiki/Category:Software_testing
• Source code of open source projects, like TYPO3: https://github.com/TYPO3/TYPO3.CMS/tree/master/typo3/sysext/core/Tests