WHEN YOU GET LOST
IN API TESTING
Paula Čučuk

About me
Paula Čučuk
paula@locastic.com
@paulala_14
Backend developer @ Locastic

Locastic
Helping clients create web
and mobile apps since 2011
• UX/UI
• Mobile apps
• Web apps
• Training & Consulting
www.locastic.com
@locastic

Intro
Experience with API testing in Locastic
Testing approach using examples from projects
Testing tools
Things we learned along the way

Manual testing
Boring
Time consuming
Unlikely to achieve acceptable coverage

Functional tests
Functional testing is defined as the testing of
complete functionality of some application.

Functional tests
In each functional tests check:
Response code
Response header
Response content: contains expected fields in expected
format

Functional tests
Test that each endpoint behaves as expected for:
OK request and response
Bad request and Validation response
Forbidden access response

CRUD Event testing with Postman

1. Import JSON Schema using OpenAPI

Open API
Allows you to specify:
Available endpoints and operations
Input and output parameters for each operation
Authentication methods
Contact information, license, terms of use and other information.
An API description format for REST APIs

Adding assertions to Collection

Environment variables

Test creating new event

Test editing created event

Test get event

Test deleting event

Test get events list

All done! Let’s run the tests

Postman tests + Newman
Run and test a Postman Collection directly from the command line

Import request from network

Let’s see the same test case in
PHPUnit

The test Http Client in API Platform

Test creating event with bad data

Test creating new event

Test get created event

Test editing event

Test get list of events

Test get list of events unauthorised

Test deleting event

Refreshing database data
hautelook/alice-bundle

Refreshing database data
dmaicher/doctrine-test-bundle

Postman vs PhpUnit speed
PhpUnit is
2.5 times
faster

Postman vs PHPUnit
Postman PHPUnit
Easy to use and setup Faster execution
Interactive documentation and
specification for FE developers and QA
More flexible
Import using Open API Free

Functional tests benefits
✓ Less bugs
✓ Faster testing
✓ Worked perfect on small project

Import results feature flow

The test pyramid

Unit tests
Unit testing is a level of testing where individual
units/components are tested. The purpose is to
validate that each separate unit performs as expected.
A unit is the smallest testable part of any software.

Import results feature flow

Racer Medal Consumer
class

Unit tests
Catch errors in early stage
Very fast execution
Easy to write

It’s not unit tests, it’s you!
Refactor your code using SOLID principles.

Import results feature flow

Test repository method example

Test repository method
example

Unit test

UNIT TEST IS NOT USEFUL HERE

Integration tests
Integration testing is the phase in software testing
in which individual software modules are combined and
tested as a group.

When to use integration tests
Validation
3rd party integration
Database queries
Verifying two or more modules which have unit tests work as
expected together

Integration test
Step 1: Prepare test data

Event Time Category Gender Distance Disqualified Race Category
1 NULL a1 male long FALSE Individual/Team
1 2:00:00 a2 male long TRUE Individual/Team
1 2:00:00 a4 male long FALSE Him & Her
1 2:01:00 a1 male long FALSE Individual/Team
1 2:05:00 a2 female long FALSE Individual/Team
1 2:10:00 a1 male long FALSE Individual/Team
1 2:10:00 a2 female long FALSE Individual/Team
1 2:40:00 a3 male medium FALSE Individual/Team
1 3:10:00 a2 female long FALSE Individual/Team
2 2:15:00 a2 female long FALSE Individual/Team

Event Time Category Gender Distance Disqualified Race Category
1 NULL a1 male long FALSE Individual/Team
1 2:00:00 a2 male long TRUE Individual/Team
1 2:00:00 a4 male long FALSE Him & Her
1 2:01:00 a1 male long FALSE Individual/Team
1 2:05:00 a2 female long FALSE Individual/Team
1 2:10:00 a1 male long FALSE Individual/Team
1 2:10:00 a2 female long FALSE Individual/Team
1 2:40:00 a3 male medium FALSE Individual/Team
1 3:10:00 a2 female long FALSE Individual/Team
2 2:15:00 a2 female long FALSE Individual/Team

Event Time Category Gender Distance Disqualified Race Category
1 NULL a1 male long FALSE Individual/Team
1 2:00:00 a2 male long TRUE Individual/Team
1 2:00:00 a4 male long FALSE Him & Her
1 2:01:00 a1 male long FALSE Individual/Team
1 2:05:00 a2 female long FALSE Individual/Team
1 2:10:00 a1 male long FALSE Individual/Team
1 2:10:00 a2 female long FALSE Individual/Team
1 2:40:00 a3 male medium FALSE Individual/Team
1 3:10:00 a2 female long FALSE Individual/Team
2 2:15:00 a2 female long FALSE Individual/Team

Event Time Category Gender Distance Disqualified Race Category
1 NULL a1 male long FALSE Individual/Team
1 2:00:00 a2 male long TRUE Individual/Team
1 2:00:00 a4 male long FALSE Him & Her
1 2:01:00 a1 male long FALSE Individual/Team
1 2:05:00 a2 female long FALSE Individual/Team
1 2:10:00 a1 male long FALSE Individual/Team
1 2:10:00 a2 female long FALSE Individual/Team
1 2:40:00 a3 male medium FALSE Individual/Team
1 3:10:00 a2 female long FALSE Individual/Team
2 2:15:00 a2 female long FALSE Individual/Team

Event Time Category Gender Distance Disqualified Race Category
1 NULL a1 male long FALSE Individual/Team
1 2:00:00 a2 male long TRUE Individual/Team
1 2:00:00 a4 male long FALSE Him & Her
1 2:01:00 a1 male long FALSE Individual/Team
1 2:05:00 a2 female long FALSE Individual/Team
1 2:10:00 a1 male long FALSE Individual/Team
1 2:10:00 a2 female long FALSE Individual/Team
1 2:40:00 a3 male medium FALSE Individual/Team
1 3:10:00 a2 female long FALSE Individual/Team
2 2:15:00 a2 female long FALSE Individual/Team

Event Time Category Gender Distance Disqualified Race Category
1 NULL a1 male long FALSE Individual/Team
1 2:00:00 a2 male long TRUE Individual/Team
1 2:00:00 a4 male long FALSE Him & Her
1 2:01:00 a1 male long FALSE Individual/Team
1 2:05:00 a2 female long FALSE Individual/Team
1 2:10:00 a1 male long FALSE Individual/Team
1 2:10:00 a2 female long FALSE Individual/Team
1 2:40:00 a3 male medium FALSE Individual/Team
1 3:10:00 a2 female long FALSE Individual/Team
2 2:15:00 a2 female long FALSE Individual/Team

Event Time Category Gender Distance Disqualified Race Category
1 NULL a1 male long FALSE Individual/Team
1 2:00:00 a2 male long TRUE Individual/Team
1 2:00:00 a4 male long FALSE Him & Her
1 2:01:00 a1 male long FALSE Individual/Team
1 2:05:00 a2 female long FALSE Individual/Team
1 2:10:00 a1 male long FALSE Individual/Team
1 2:10:00 a2 female long FALSE Individual/Team
1 2:40:00 a3 male medium FALSE Individual/Team
1 3:10:00 a2 female long FALSE Individual/Team
2 2:15:00 a2 female long FALSE Individual/Team

Integration test
Step 2: trigger repository method and check if data updated as
expected

Test payment endpoint example

Test payment - mocking 3rd party calls

Test payment - functional test

New approach benefits
More coverage, less bugs
Faster test execution
Easier and faster refactoring
Improving code quality
Time saving

Handy testing tools

Infection
Tool for mutation testing in PHP

PHP Stan
PHP Static Analysis Tool

Continuous integration (CI)
Tool for tuning tests on GIT

What we learned along the way

Do I need to write tests first?
It’s just one of the approaches

Do I need to have 100% coverage?
100% coverage doesn’t guarantee your code is
fully tested and working

What about legacy code?
1. Start replicating bugs with tests before fixing them
2. Test at least most important and critical parts

How do I test some specific code?
Check out the tests of the libraries and framework you
are using

How do I know if the tests I wrote are good
enough?
Ask yourself:
“Am I sure the code I tested works as it should?”

Conclusion
You should write tests!
Think about your projects requirements
If something is hard to test - refactor it
Check out the tools we mentioned

Thank you!

Questions?
https://joind.in/talk/908a3
Paula Čučuk
paula@locastic.com
@paoolala
Backend developer @ Locastic