A note on these slides

1. simplified version of slides from actual workshop
2. use MDX-deck

3. raw MDX deck can be viewed in git repo

   • github docs/slides/deck.mdx
4. to see speaker notes OPTION-p (⌥ p) on mac

Install - code

• git clone git@github.com/failure-driven/bdd-workshop-app.git
• Ruby 2.6.2, Node 10.15.3, PostgreSQL, Chrome

bundle install && yarn install
bin/rails db:create db:migrate
make
bin/rails server

Install - Kahoot

• https://kahoot.com/mobile-app/
• Or directly https://kahoot.it/

Fresho

Test Driven Design

Behaviour Driven Design

Modules

1. The Unit Under Test
2. When Then Steps
3. Flows vs Mechanics
4. Add a Feature with Outside-In BDD

Module 1

The Unit Under Test

React + Rails

Testing boundaries

Integration tests and the rest

How does the app work?

Open spec/features/monster_spec.rb

How does the app really work?

Let’s take a look

1. The Unit under Test - Review

• Units under test

  • Frontend & backend together - Integration
  • Backend (API to DB) - Integration
  • Components - Isolated unit
• Read tests, understand how the system works

Module 2

When Then steps

From
Given/When/Then
To
series of When/Then

"When" "Then"
flows through the system

Let's take a look

code dive

2. When Then steps - Review

• Integration specs

  • ‘When Then’ pair denotes behaviour
  • Multiple ‘When Then’ behaviours per scenario
  • Owned by developers
  • First code you write!
• gem rspec-example_steps

Module 3

Flows vs Mechanics

The problem

A solution

Flows

• Driven by external interface
• Particular sequence of events
• Effects of a series of interactions
• Multiple actors

Mechanics

• Driven by partial interface
• Immediate behaviour of one unit
• Single actor
• No critical flow on effects
• Exercise in more detail

A solution

• Separate different responsibilities
• Organise tests
• Scale your test suite!

Let's take a look

code dive

3. Flows vs Mechanics - Review

• Organise integration tests
• Document how system works

• Flows

  • Effects of a series of interactions
  • Multiple actors

• Mechanics

  • Immediate behaviour of one unit
  • Single actor

Module 4

Add a Feature with Outside-In BDD

Testing boundaries

• Every test is a unit test

Testing boundaries

• Flow

  • Full system integration
  • API, controller, model, db and frontend
  • Test flows with core alternate outcomes

Testing boundaries

• Mechanic

  • Full system integration
  • API, controller, model, db and single component
  • Test user experience when errors/loading occur

Testing boundaries

• Component

  • Isolated unit
  • Test wrong/missing params passed in

Testing boundaries

• API

  • Backend integration
  • Test valid/invalid request params
  • Test response to valid/invalid params

Testing boundaries

• Controller

  • Isolated unit
  • Test collaboration with other units

Testing boundaries

• Model (domain)

  • Isolated unit
  • Test data retrieval
  • Test actions performed on that data

New feature

• What is the new feature?
• How do we drive this feature with BDD?

Let's take a look

code dive

Complete the feature

• Flow - pending
• Mechanic - assert age shows up in profile page
• Component - render age in profile component
• API - show view responds with age value
• Controller - show view responds with age value

• Model - TDD age method

  • return nil when player does not have dob
  • calculate age when birthday is today
  • calculate age when birthday is tomorrow
  • Hint: Timecop.freeze in gemfile

Complete the feature

git pull --rebase   OR 
git clone git@github.com/failure-driven/bdd-workshop-app.git

• docs/complete_the_feature_challenge.md
• complete solution by [date]
• tweet us if you get stuck @selenasmall88 @saramic

Image credits

• Photo by Sean Stratton on Unsplash slide 1
• https://medium.com/@Cyrdup/unit-testing-yourea-doing-it-wrong-407a07692989 slide 6
• Photo by Nicolas Thomas on Unsplash slide 9
• Photo by israel palacio on Unsplash slide 15
• Photo by Ugne Vasyliute on Unsplash slide 20
• Photo by Jeremy Bishop on Unsplash slide 21
• Photo by Ravi Pinisetti on Unsplash slide 23
• https://www.instagram.com/bahamasgirl/ slide 29
• Photo by Blake Cheek on Unsplash module 4
• Photo by Jakob Boman on Unsplash module 4

RailsConf 2019

Abigail Phoenix & Marty Haught

Melbourne Ruby & Dev community

Paal Ringstad from @LeWagonMEL Jessie Wang from Code Mentoring Melbourne @ceels @NessNimmo @Quintrino

Fresho

Huw Birrell & James Andronis

Fresho Dev Team Dave, Patrick, Mark, Dan

Perryn Fowler

@perrynfowler