raviwu/rspec_pattens.rb

## rspec_pattens.rb
# app/models/user.rb
class User < ActiveRecord::Base
  has_secure_password

  validates :firstname, presence: true, length: 4..20
  validates :middlename, length: 4..20, allow_blank: true
  validates :lastname, presence: true, length: 4..20
  validates :email, format: { with: /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i }
  validates :password, presence: true, confirmation: true, length: { minimum: 8 }

  # ...

  def fullname
    [firstname, middlename, lastname].compact.join(' ')
  end
end

# ======= Minimum Valid Object =======

# Workflow:
# 1. Build the Ojbect
# 2. Assign valid attributes
# 3. Assert the valid state
# 4. Mutate the attribute that expected to be invalid

describe User do
  subject(:user) do
    # 1. Build the Ojbect
    described_class.new(
      firstname: firstname,
      middlename: middlename,
      lastname: lastname,
      email: email,
      password: password
    )
  end
  # 2. Assign valid attributes
  let(:firstname) { 'Ravi' }
  let(:middlename) { nil }
  let(:lastname) { 'Wurzmann' }
  let(:email) { 'raviwu@gmail.com' }
  let(:password) { 'Passw0rd!' }

  # 3. Assert the valid state
  it { is_expected.to be_valid }

  context 'with a firstname that is over 20 chars' do
    # 4. Mutate the attribute that expected to be invalid
    let(:firstname) { 'a very very very very long long long long long long long firstname' }

    it { is_expected.to be_invalid }
  end

  context 'with a firstname that is less than 4 chars' do
    let(:firstname) { 'srt' }

    it { is_expected.to be_invalid }
  end
end

# ======= Permutation Table =======

# Workflow:
# 1. Define sets of data
# 2. Define the output of each set
# 3. Assert the method creates the output from the data (input/output)

describe User do
  # ... continue previous setup for valid subject
  describe '#fullname' do
    shared_examples_for 'a fullname' do|(first, middle, last), output|
      subject(:fullname) { user.fullname }

      let(:firstname) { first }
      let(:middlename) { middle }
      let(:lastname) { last }

      it { is_expected.to eq output }
    end

    {
      ['Ravi', 'LW', 'Wurzmann'] => 'Ravi LW Wurzmann',
      [nil, 'LW', 'Wurzmann']    => 'LW Wurzmann',
      ['Ravi', nil, 'Wurzmann']  => 'Ravi Wurzmann',
      ['Ravi', 'LW', nil]        => 'Ravi LW',
      [nil, nil, 'Wurzmann']     => 'Wurzmann',
      [nil, 'LW', nil]           => 'LW',
      ['Ravi', nil, nil]         => 'Ravi',
      [nil, nil, nil]            => ''
    }.each do |name_set, output|
      it_behaves_like 'a fullname', name_set, output
    end
  end
end

# ======= Golden Master =======

# This is not a good practice for large scale testing, this kind of manually approval should apply on limited and isolated tests

# Purpose:
# 1. Backfilling untested legacy code
# 2. Uncertain expectations require visual confirmation
# 3. Code complexity significantly exceeds current domain knowledge

# Workflow:
# 1. Take a snapshot of an object (to a file)
# 2. Verify the snapshot (manually)
# 3. Compare future versions to the verified 'master'

# https://github.com/kytrinyx/approvals

# spec/spec_helper.rb
require 'approvals/rspec'

# path/to/test_spec.rb
it 'works' do
  verify format: :html do
    "<html><head></head><body><h1>Ruby on Rails</h1></body></html>"
  end
end

# Manually verify snapshots
$ cd /path/to/app
$ approvals verify

# ======= Suggested Practice =======

# use `let(:user)` instead of instance variables `@user`

# descriptive naming
  it { expect(user).to be_valid }
  it { expect(user_with_duplicated_email).to be_invalid }
  # better than...
  it { expect(user1).to be_valid }
  it { expect(user2).to be_invalid }

# extract common expectations
  # custom mather might help if same expectation logic is repeatly occurs

# factories over fixtures
  # https://github.com/thoughtbot/factory_girl
  # `FactoryGirl.lint!` can run all the factory setup and tells if the setup are valid, hence
  # `FactoryGirl.lint!` can be treated as a MVO instead of building from `Class.new`
describe User do
  subect(:user) { FactoryGirl.build :user }
end

# After Readings:
# http://randycoulman.com/blog/categories/getting-testy/
# http://betterspecs.org/
# http://www.poodr.com/
	# app/models/user.rb
	class User < ActiveRecord::Base
	has_secure_password

	validates :firstname, presence: true, length: 4..20
	validates :middlename, length: 4..20, allow_blank: true
	validates :lastname, presence: true, length: 4..20
	validates :email, format: { with: /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i }
	validates :password, presence: true, confirmation: true, length: { minimum: 8 }

	# ...

	def fullname
	[firstname, middlename, lastname].compact.join(' ')
	end
	end

	# ======= Minimum Valid Object =======

	# Workflow:
	# 1. Build the Ojbect
	# 2. Assign valid attributes
	# 3. Assert the valid state
	# 4. Mutate the attribute that expected to be invalid

	describe User do
	subject(:user) do
	# 1. Build the Ojbect
	described_class.new(
	firstname: firstname,
	middlename: middlename,
	lastname: lastname,
	email: email,
	password: password
	)
	end
	# 2. Assign valid attributes
	let(:firstname) { 'Ravi' }
	let(:middlename) { nil }
	let(:lastname) { 'Wurzmann' }
	let(:email) { 'raviwu@gmail.com' }
	let(:password) { 'Passw0rd!' }

	# 3. Assert the valid state
	it { is_expected.to be_valid }

	context 'with a firstname that is over 20 chars' do
	# 4. Mutate the attribute that expected to be invalid
	let(:firstname) { 'a very very very very long long long long long long long firstname' }

	it { is_expected.to be_invalid }
	end

	context 'with a firstname that is less than 4 chars' do
	let(:firstname) { 'srt' }

	it { is_expected.to be_invalid }
	end
	end

	# ======= Permutation Table =======

	# Workflow:
	# 1. Define sets of data
	# 2. Define the output of each set
	# 3. Assert the method creates the output from the data (input/output)

	describe User do
	# ... continue previous setup for valid subject
	describe '#fullname' do
	shared_examples_for 'a fullname' do\|(first, middle, last), output\|
	subject(:fullname) { user.fullname }

	let(:firstname) { first }
	let(:middlename) { middle }
	let(:lastname) { last }

	it { is_expected.to eq output }
	end

	{
	['Ravi', 'LW', 'Wurzmann'] => 'Ravi LW Wurzmann',
	[nil, 'LW', 'Wurzmann'] => 'LW Wurzmann',
	['Ravi', nil, 'Wurzmann'] => 'Ravi Wurzmann',
	['Ravi', 'LW', nil] => 'Ravi LW',
	[nil, nil, 'Wurzmann'] => 'Wurzmann',
	[nil, 'LW', nil] => 'LW',
	['Ravi', nil, nil] => 'Ravi',
	[nil, nil, nil] => ''
	}.each do \|name_set, output\|
	it_behaves_like 'a fullname', name_set, output
	end
	end
	end

	# ======= Golden Master =======

	# This is not a good practice for large scale testing, this kind of manually approval should apply on limited and isolated tests

	# Purpose:
	# 1. Backfilling untested legacy code
	# 2. Uncertain expectations require visual confirmation
	# 3. Code complexity significantly exceeds current domain knowledge

	# Workflow:
	# 1. Take a snapshot of an object (to a file)
	# 2. Verify the snapshot (manually)
	# 3. Compare future versions to the verified 'master'

	# https://github.com/kytrinyx/approvals

	# spec/spec_helper.rb
	require 'approvals/rspec'

	# path/to/test_spec.rb
	it 'works' do
	verify format: :html do
	"<html><head></head><body><h1>Ruby on Rails</h1></body></html>"
	end
	end

	# Manually verify snapshots
	$ cd /path/to/app
	$ approvals verify

	# ======= Suggested Practice =======

	# use `let(:user)` instead of instance variables `@user`

	# descriptive naming
	it { expect(user).to be_valid }
	it { expect(user_with_duplicated_email).to be_invalid }
	# better than...
	it { expect(user1).to be_valid }
	it { expect(user2).to be_invalid }

	# extract common expectations
	# custom mather might help if same expectation logic is repeatly occurs

	# factories over fixtures
	# https://github.com/thoughtbot/factory_girl
	# `FactoryGirl.lint!` can run all the factory setup and tells if the setup are valid, hence
	# `FactoryGirl.lint!` can be treated as a MVO instead of building from `Class.new`
	describe User do
	subect(:user) { FactoryGirl.build :user }
	end

	# After Readings:
	# http://randycoulman.com/blog/categories/getting-testy/
	# http://betterspecs.org/
	# http://www.poodr.com/