Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
factory_boy: testing like a pro. DjangoCon EU 2022
Search
Camila Maia
September 22, 2022
Technology
1
290
factory_boy: testing like a pro. DjangoCon EU 2022
https://pretalx.evolutio.pt/djangocon-europe-2022/talk/XWUYA8/
Camila Maia
September 22, 2022
Tweet
Share
More Decks by Camila Maia
See All by Camila Maia
Cumbuca Dev: Ensinando com Open Source - 71º Python Floripa no MeLi
camilamaia
0
44
COMO E PORQUE ENSINAR A PROGRAMAR COM OPEN SOURCE - Python Brasil 2023
camilamaia
0
38
Como testar e manter APIs de qualidade - Codecon Digital 2023
camilamaia
0
270
factory_boy: testing like a pro. DjangoCon US 2022
camilamaia
0
260
ScanAPI Workshop. DjangoCon EU 2022
camilamaia
0
210
Como testar e documentar REST APIs com ScanAPI - Agile Testers Conference 2021
camilamaia
0
160
factory_boy: Testando Objetos Complexos Python Brasil 2021
camilamaia
0
270
Open Source: Você conhece? Sabe como e por que contribuir?
camilamaia
0
190
PrograMaria 2021
camilamaia
0
190
Other Decks in Technology
See All in Technology
10分でわかるfreeeのQA
freee
1
3.4k
Commitment vs Harrisonism - Keynote for Scrum Niseko 2024
miholovesq
6
1.6k
Mini Tokyo 3D × PLATEAU - 公共交通デジタルツインにリアルな風景を
nagix
1
230
Engineering at LY Corporation
lycorp_recruit_jp
0
160
DatabricksにおけるLLMOpsのベストプラクティス
taka_aki
4
1.6k
AWS⼊社という選択肢、⾒えていますか
iwamot
2
1.1k
QAEチームが辿った3年 ボクらが改善業務にスクラムを選んだワケ / 20241108_cloudsign_ques23
bengo4com
0
540
マイベストのデータ基盤の現在と未来 / mybest-data-infra-asis-tobe
mybestinc
2
1.8k
株式会社ログラス − エンジニア向け会社説明資料 / Loglass Comapany Deck for Engineer
loglass2019
3
28k
State of Open Source Web Mapping Libraries
dayjournal
0
200
コンテナのトラブルシューティング目線から AWS SAW についてしゃべってみる
kazzpapa3
1
120
Autify Company Deck
autifyhq
1
39k
Featured
See All Featured
The Psychology of Web Performance [Beyond Tellerrand 2023]
tammyeverts
42
2.2k
4 Signs Your Business is Dying
shpigford
180
21k
JavaScript: Past, Present, and Future - NDC Porto 2020
reverentgeek
47
5k
The Myth of the Modular Monolith - Day 2 Keynote - Rails World 2024
eileencodes
15
2k
Java REST API Framework Comparison - PWX 2021
mraible
PRO
28
8.2k
Stop Working from a Prison Cell
hatefulcrawdad
267
20k
Music & Morning Musume
bryan
46
6.2k
Build The Right Thing And Hit Your Dates
maggiecrowley
33
2.4k
Art, The Web, and Tiny UX
lynnandtonic
297
20k
For a Future-Friendly Web
brad_frost
175
9.4k
個人開発の失敗を避けるイケてる考え方 / tips for indie hackers
panda_program
92
16k
Principles of Awesome APIs and How to Build Them.
keavy
126
17k
Transcript
@cmaiacd factory_boy DjangoCon EU 2022 - Porto Camila Maia
testing like a pro
@cmaiacd You can find this presentation at: speakerdeck.com/cmaiacd
@cmaiacd Who am I?
@cmaiacd Backend Developer @
@cmaiacd Brazilian
@cmaiacd Living in Berlin
@cmaiacd Queer
@cmaiacd 🐶
@cmaiacd Coding since 2010 👵
@cmaiacd Python 🐍 and Ruby 💎
@cmaiacd Community ❤
@cmaiacd Conferences
@cmaiacd Open Source ❤
@cmaiacd Creator of ScanAPI
@cmaiacd +1.5k + 1.2k ⭐
@cmaiacd Workshop Tomorrow 4:55 PM
@cmaiacd
@cmaiacd factory_boy: what is it?
@cmaiacd It is a fixtures replacement
@cmaiacd Based on factory_bot (Thoughtbot)
@cmaiacd First version: Django only Nowadays: framework-independent Unittest, Pytest...
@cmaiacd For complex objects: ❌ Fixtures: static, hard to maintain
✅ Factories: easy-to-use
@cmaiacd
@cmaiacd 🧰 🛠 🔧 ⚙ Sequence Faker Fuzzy attributes LazyFunction
LazyAttribute Inheritance Inheritance Params Traits Strategies RelatedFactory / SubFactory
@cmaiacd My Experience
@cmaiacd +3 years Django Monolith 🐘
@cmaiacd +230 tables +2200 relevant files +75k relevant lines
@cmaiacd
@cmaiacd A poorly designed factory might affect many tests
@cmaiacd Implicit errors
@cmaiacd The tests are created in a way to fit
the factory factory-oriented testing
@cmaiacd Factories can get too tied
@cmaiacd Developers bump into the same issue again and again
@cmaiacd Patterns 👀 Best practices? 🤔
@cmaiacd Demo App
@cmaiacd Polls
@cmaiacd Poll
@cmaiacd Results
@cmaiacd s
@cmaiacd Model - Poll Poll Question Choice n:1 pub_date :
DateTimeField premium : BooleanField author : CharField question_text : CharField language : CharField choice_text : CharField votes : IntegerField 1:1
@cmaiacd Model - Poll
@cmaiacd Model - Poll
@cmaiacd Model - Question
@cmaiacd Model - Choice
@cmaiacd Best Practices
@cmaiacd 1. FACTORIES SHOULD REPRESENT THEIR MODELS
@cmaiacd Avoid implicit errors
@cmaiacd BAD ❌
@cmaiacd GOOD ✅
@cmaiacd 2. DO NOT RELY ON DEFAULTS FROM FACTORIES
@cmaiacd • If a default value is changed, all tests
that depend on it will break • The setup of a test should contain all the logic to ensure it will always pass • Explicit better than implicit
@cmaiacd BAD ❌
@cmaiacd GOOD ✅
@cmaiacd 3. FACTORIES SHOULD CONTAIN ONLY THE REQUIRED DATA
@cmaiacd If the field is nullable (null=True) the attribute should
be under a trait and not as a default value
@cmaiacd BAD ❌
@cmaiacd GOOD ✅
@cmaiacd If we want to have an author, we can
use PollFactory(with_author=True) now When are we going to remember to test the case PollFactory(author=None)? We should not assume there is an author when DB actually allows to not have it.
@cmaiacd 4. BUILD OVER CREATE
@cmaiacd MyFactory.build() creates a local object (memory) MyFactory.create() creates a
local object + stores it in the DB
@cmaiacd BAD ❌
@cmaiacd GOOD ✅
@cmaiacd BUILD STRATEGY ========== 14 passed in 1.76 seconds ==========
CREATE STRATEGY ========== 14 passed in 3.26 seconds ==========
@cmaiacd 5. IF FK IS IN THE TABLE: SUBFACTOR IF
FK IS IN THE OTHER TABLE: RELATEDFACTORY + TRAIT
@cmaiacd SubFactory: builds/creates the SubFactory during the process of creation
of the main factory RelatedFactory: builds/creates the RelatedFactory after creating the main factory
@cmaiacd Good ✅
@cmaiacd 6. USE FIXTURES TO WRAP FACTORIES TO AVOID DUPLICATION
@cmaiacd BAD ❌
@cmaiacd GOOD ✅
@cmaiacd 7. AVOID SHARING FACTORIES OR FIXTURES AMONG DIFFERENT FILES
@cmaiacd Many tests depending on the same factory/fixture
@cmaiacd Tends to inflate the factory/fixture
@cmaiacd Hard to maintain
@cmaiacd Change a factory/fixture… tons of tests breaking
@cmaiacd Fixture / Factory oriented testing
@cmaiacd Ok, ok, I got it! 😌 Now I know
the best practices 💪
@cmaiacd So let’s try to fix one first factory… 🤓
@cmaiacd
@cmaiacd Baby steps 🐣
@cmaiacd Código
@cmaiacd Official doc 📄 factoryboy.readthedocs.io
@cmaiacd Common recipes factoryboy.readthedocs.io/ en/stable/recipes.html
@cmaiacd Code github.com/FactoryBoy/ factory_boy
@cmaiacd THANK YOU! MUITO OBRIGADA! @cmaiacd camilamaia cmaiacd.com