The document discusses the importance and implementation of automated regression, unit, and acceptance tests in a REST API using tools like PHPUnit and Behat. It highlights the benefits of testing, such as fast feedback and ensuring software quality, while outlining best practices for executing tests and integrating continuous testing into the development process. The document also addresses the challenges of testing, including the commitment required for Test Driven Development (TDD) and achieving full test coverage.

1. Automated Tests in a REST API
by Luís Nóbrega

2. Regression Tests - benefits
Fast feedback
Discover introduced software bugs (regression)
Verify bug fixes on existing functionality
Validate changes against other components
Include re-running of previous tests
Can be executed on each code change

3. Regression Tests - when to do it?
Specification has changed
Code has been changed
Add new test cases - increase
coverage
New bugs were detected
Create a new test that reproduces the
bug.

4. Regression Tests - State of the Art
Unit Tests - Test Driven Development (TDD) and Behavior
Driven Development (BDD)
Tools: PHPUnit and phpspec
Acceptance Tests
Tool: Behat

5. Unit Tests
Must run successfully on each change.
Tests should be written with/before code. We send inputs and verify outputs.
All dependencies are mocked. No hitting the database, file system or network.
Tests written by developers for developers.
Benefits
Allow safe refactoring of code parts.
It can work as documentation.
Gives higher confidence.

6. Unit Tests - When to Create?
Always, if it makes sense.
When you are fixing a bug. Reproduce it with a test.
When implementing new features or when specification has
changed.
Check code coverage report to add new test cases

7. Unit Tests - How to execute?
PHPUnit
Execute: bin/phpunit -c app/
phpspec
Execute: bin/phpspec run
Create (describe) a new spec: bin/phpspec desc ‘<namespace>’
Execute with code coverage: bin/phpspec run --config=<config-file>.yml
Code coverage will be exported to build/coverage folder

8. Acceptance Tests - Behat
Verify the functional requirements
Ensure that the overall application is working
Test specification provided
Prevent regression problems
“Behat is an open source behavior-driven development
framework (...) What is behavior-driven development, you ask?
It’s the idea that you start by writing human-readable sentences
that describe a feature of your application and how it should
work, and only then implement this behavior in software.”

9. Behat - Database for test environment
Two concerns: performance and isolation
Performance
Isolation: each test data is only visible for that test.
How to setup the database before each test? Approaches:
Obelix doctrine commands - 3 minutes
Drop, create and add only structure using entities
MySQL via command line - 1 minute

10. Behat - Database data fixtures
app/config/automated_tests.yml has data fixtures config with tables and data
files
Data files must exist in app/data/test/mysql
In the scenario we should add a tag with the data fixture we need
Basic authentication is always inserted in the database

11. Behat - Lifecycle request
REST API
in test environment
image: Symfony lifecycle request
Behat
sends HTTP request
Behat
asserts HTTP response
Feature Scenario
Before Scenario hook
setup database:
- create an database dump
- drop test database
- create test database
- import dump
- import data
Given - precondition
When - action
Then - testable outcome
is achieved
runs iteratively
Loop over features -> loop over scenarios of the feature

12. Behat
Event system

13. The future - Continuous Integration
Triggers test chain on each pull request
Verifies state before merge
Using the GitHub API to validate pull-request even before they are merged!
https://developer.github.com/v3/repos/statuses/
Continuous Integration Best Practices
(...)
Make the build self-testing
Once the code is built, all tests should run to confirm
that it behaves as the developers expect it to behave.

14. Lessons learned - Benefits and Difficulties
Commitment to TDD needed
Testing influences software design
Testing takes time
Full test coverage is almost unachievable
Testing is needed to ensure software quality

15. Questions?

16. Thanks