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Readable RSpec
Kento Nagata / Wantedly Engineer
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ಡΈ͍͢RSpecʹ͍ͭͯ
͓Λ͍ͨ͠ͱࢥ͍·͢ɻ
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ࣗݾհ
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Ӭా݈ਓ
8BOUFEMZ
*OD8FC&OHJOFFS
8PSL
8BOUFEMZ
*OD
8FC&OHJOFFS
8BOUFEMZ7JTJUͷ։ൃվળ
8BOUFEMZ5PPMTͷ։ൃվળ
7JJCBS
*OD
8FC&OHJOFFS
ϚονϯάαʔϏε͓Αͼ੍࡞ࢧԉπʔϧͷ։ൃ
!OHULOU !OHUL
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ͦΕͰຊʹ
Γ·͢ɻ
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લఏ
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RSpec 3.6.0
FactoryGirl 4.8.0
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Table of contents
* Describe and context
* Use single-level contexts
* Use let and before
* Use subject and named subject
* Reserved DRY
* Expect change
* Should not update context value
* Set all significant fields on test data
* Write expectations at a high level
* Should not use "should" in our example names
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Describe and context
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Describe and context
• describeͱcontextΛ͍͚Δ
• describeςετରΛॻ͘
• contextςετ͕࣮ߦ͞ΕΔલఏ݅ঢ়ଶΛॻ͘
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RSpec.describe Book do
describe '#reserve' do
it 'raises already reserved error when already reserved' do
# ...
end
it 'reserves the book when the book is available' do
# ...
end
end
end
Describe and context
RSpec.describe Book do
describe '#reserve' do
context 'when already reserved' do
it 'raises already reserved error' do
# ...
end
end
context 'the book is available' do
it 'reserves the book' do
# ...
end
end
end
end
Better
/PUGood
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Use single-level contexts
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Use single-level contexts
• ContextΛωετͤ͞ͳ͍
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RSpec.describe Book do
describe '#reserve' do
context 'when already reserved' do
let(:reserved) { true }
context 'when the users reservation limit is exceeded' do
let(:exceeded) { true }
# ...
end
context 'when the users reservation limit is not exceeded' do
let(:exceeded) { false }
# ...
end
end
context 'the book is available' do
let(:reserved) { false }
context 'when the users reservation limit is exceeded' do
let(:exceeded) { true }
# ...
end
context 'when the users reservation limit is not exceeded' do
let(:exceeded) { false }
# ...
end
end
end
end
Use single-level contexts
RSpec.describe Book do
describe '#reserve' do
context 'when already reserved and the user reservation limit is exceeded' do
let(:reserved) { true }
let(:exceeded) { true }
# ...
end
context 'when already reserved and the users reservation limit is not exceeded' do
let(:reserved) { true }
let(:exceeded) { false }
# ...
end
context 'the book is available and the user reservation limit is exceeded' do
let(:reserved) { false }
let(:exceeded) { true }
# ...
end
context 'the book is available and the user has enough reservation limit' do
let(:reserved) { false }
let(:exceeded) { false }
# ...
end
end
end
Better
/PUGood
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RSpec.describe Book do
describe '#reserve' do
context 'when already reserved' do
let(:reserved) { true }
context 'when the users reservation limit is exceeded' do
let(:exceeded) { true }
# ...
end
context 'when the users reservation limit is not exceeded' do
let(:exceeded) { false }
# ...
end
end
context 'the book is available' do
let(:reserved) { false }
context 'when the users reservation limit is exceeded' do
let(:exceeded) { true }
# ...
end
context 'when the users reservation limit is not exceeded' do
let(:exceeded) { false }
# ...
end
end
end
end
Use single-level contexts
RSpec.describe Book do
describe '#reserve' do
context 'when already reserved and the user reservation limit is exceeded' do
let(:reserved) { true }
let(:exceeded) { true }
# ...
end
context 'when already reserved and the users reservation limit is not exceeded' do
let(:reserved) { true }
let(:exceeded) { false }
# ...
end
context 'the book is available and the user reservation limit is exceeded' do
let(:reserved) { false }
let(:exceeded) { true }
# ...
end
context 'the book is available and the user has enough reservation limit' do
let(:reserved) { false }
let(:exceeded) { false }
# ...
end
end
end
Better
/PUGood
RSpec.describe Book do
describe '#reserve' do
context 'when already reserved' do
let(:reserved) { true }
context 'when the users reservation limit is exceeded' do
let(:exceeded) { true }
# ...
end
end
end
/PUGood
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RSpec.describe Book do
describe '#reserve' do
context 'when already reserved' do
let(:reserved) { true }
context 'when the users reservation limit is exceeded' do
let(:exceeded) { true }
# ...
end
context 'when the users reservation limit is not exceeded' do
let(:exceeded) { false }
# ...
end
end
context 'the book is available' do
let(:reserved) { false }
context 'when the users reservation limit is exceeded' do
let(:exceeded) { true }
# ...
end
context 'when the users reservation limit is not exceeded' do
let(:exceeded) { false }
# ...
end
end
end
end
Use single-level contexts
RSpec.describe Book do
describe '#reserve' do
context 'when already reserved and the user reservation limit is exceeded' do
let(:reserved) { true }
let(:exceeded) { true }
# ...
end
context 'when already reserved and the users reservation limit is not exceeded' do
let(:reserved) { true }
let(:exceeded) { false }
# ...
end
context 'the book is available and the user reservation limit is exceeded' do
let(:reserved) { false }
let(:exceeded) { true }
# ...
end
context 'the book is available and the user has enough reservation limit' do
let(:reserved) { false }
let(:exceeded) { false }
# ...
end
end
end
Better
/PUGood
RSpec.describe Book do
describe '#reserve' do
context 'when already reserved and the user reservation limit is exceeded' do
let(:reserved) { true }
let(:exceeded) { true }
# ...
end
end
end
#FUUFS
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RSpec.describe Book do
describe '#reserve' do
context 'when already reserved' do
let(:reserved) { true }
context 'when the users reservation limit is exceeded' do
let(:exceeded) { true }
# ...
end
context 'when the users reservation limit is not exceeded' do
let(:exceeded) { false }
# ...
end
end
context 'the book is available' do
let(:reserved) { false }
context 'when the users reservation limit is exceeded' do
let(:exceeded) { true }
# ...
end
context 'when the users reservation limit is not exceeded' do
let(:exceeded) { false }
# ...
end
end
end
end
Use single-level contexts
RSpec.describe Book do
describe '#reserve' do
context 'when already reserved and the user reservation limit is exceeded' do
let(:reserved) { true }
let(:exceeded) { true }
# ...
end
context 'when already reserved and the users reservation limit is not exceeded' do
let(:reserved) { true }
let(:exceeded) { false }
# ...
end
context 'the book is available and the user reservation limit is exceeded' do
let(:reserved) { false }
let(:exceeded) { true }
# ...
end
context 'the book is available and the user has enough reservation limit' do
let(:reserved) { false }
let(:exceeded) { false }
# ...
end
end
end
Better
/PUGood
RSpec.describe Book do
describe '#reserve' do
context 'when already reserved and the user reservation limit is exceeded' do
let(:reserved) { true }
let(:exceeded) { true }
# ...
end
context 'when already reserved and the users reservation limit is not exceeded' do
let(:reserved) { true }
let(:exceeded) { false }
# ...
end
end
end
#FUUFS
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Use let and before
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Use let and before
• letͱbeforeΛͬͯcontextΛ໌֬ʹ͢Δ
• context ϒϩοΫͷԼʹॻ͘
• ੜޙʹࢀর͢ΔΦϒδΣΫτletΛ͏
• ੜޙʹࢀর͠ͳ͍ΦϒδΣΫτbeforeΛ͏
• ΠϯελϯεมΘͳ͍
• typoͯ͠ؾ͖ͮΒ͍
• `before(:each)`ͲͷexampleͰΔͨΊແବʹΞαΠϯ͞ΕΔ
• ϩʔΧϧมͱࠞࡏ͢ΔͱϦϑΝΫλͮ͠Β͍
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# Case 1
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
it 'returns falsey value' do
reserved = true
book = Book.new(reserved: reserved)
book.reserve
expect(book.reserved).to be_falsey
end
end
end
end
# Case 2
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
before do
@reserved = true
@book = Book.new(reserved: reserved)
@book.reserve
end
it 'returns falsey value' do
expect(@book.reserve).to be_falsey
end
end
end
end
Use let and before
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(reserved: reserved) }
context 'when the book is already reserved' do
let(:reserved) { true }
it 'returns falsey value' do
is_expected.to be_falsey
end
end
end
end
Better
/PUGood
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# Case 1
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
it 'returns falsey value' do
reserved = true
book = Book.new(reserved: reserved)
book.reserve
expect(book.reserved).to be_falsey
end
end
end
end
# Case 2
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
before do
@reserved = true
@book = Book.new(reserved: reserved)
@book.reserve
end
it 'returns falsey value' do
expect(@book.reserve).to be_falsey
end
end
end
end
Use let and before
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(reserved: reserved) }
context 'when the book is already reserved' do
let(:reserved) { true }
it 'returns falsey value' do
is_expected.to be_falsey
end
end
end
end
Better
/PUGood
# Case 1
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
it 'returns falsey value' do
reserved = true
book = Book.new(reserved: reserved)
book.reserve
expect(book.reserved).to be_falsey
end
end
end
end
/PUGood DPOUFYU͕Կ͔͕Θ͔ΓͮΒ͍
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# Case 1
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
it 'returns falsey value' do
reserved = true
book = Book.new(reserved: reserved)
book.reserve
expect(book.reserved).to be_falsey
end
end
end
end
# Case 2
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
before do
@reserved = true
@book = Book.new(reserved: reserved)
@book.reserve
end
it 'returns falsey value' do
expect(@book.reserve).to be_falsey
end
end
end
end
Use let and before
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(reserved: reserved) }
context 'when the book is already reserved' do
let(:reserved) { true }
it 'returns falsey value' do
is_expected.to be_falsey
end
end
end
end
Better
/PUGood
/PUGood DPOUFYU͕Կ͔͕Θ͔ΓͮΒ͍
# Case 1
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
it 'returns falsey value' do
reserved = true
book = Book.new(reserved: reserved)
book.reserve
expect(book.reserved).to be_falsey
end
end
end
end
͕͜͜DPOUFYU
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# Case 1
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
it 'returns falsey value' do
reserved = true
book = Book.new(reserved: reserved)
book.reserve
expect(book.reserved).to be_falsey
end
end
end
end
# Case 2
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
before do
@reserved = true
@book = Book.new(reserved: reserved)
@book.reserve
end
it 'returns falsey value' do
expect(@book.reserve).to be_falsey
end
end
end
end
Use let and before
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(reserved: reserved) }
context 'when the book is already reserved' do
let(:reserved) { true }
it 'returns falsey value' do
is_expected.to be_falsey
end
end
end
end
Better
/PUGood
# Case 2
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
before do
@reserved = true
@book = Book.new(reserved: reserved)
@book.reserve
end
it 'returns falsey value' do
expect(@book.reserve).to be_falsey
end
end
end
end
/PUGood *OTUBODFWBSJBCMFΛΘͳ͍
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# Case 1
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
it 'returns falsey value' do
reserved = true
book = Book.new(reserved: reserved)
book.reserve
expect(book.reserved).to be_falsey
end
end
end
end
# Case 2
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
before do
@reserved = true
@book = Book.new(reserved: reserved)
@book.reserve
end
it 'returns falsey value' do
expect(@book.reserve).to be_falsey
end
end
end
end
Use let and before
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(reserved: reserved) }
context 'when the book is already reserved' do
let(:reserved) { true }
it 'returns falsey value' do
is_expected.to be_falsey
end
end
end
end
Better
/PUGood
/PUGood ΠϯελϯεมΛΘͳ͍
# Case 2
RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
before do
@reserved = true
@book = Book.new(reserved: reserved)
@book.reserve
end
it 'returns falsey value' do
expect(@book.reserve).to be_falsey
end
end
end
end
FYBNQMFຖͰݺΕͯ͠·͏
ϩʔΧϧมͱͷ۠ผ͕
͘͠ͳΔ
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RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
it 'returns falsey value' do
reserved = true
book = Book.new(reserved: reserved)
book.reserve
expect(book.reserved).to be_truthy
end
end
end
end
RSpec.describe Book do
describe '#reserve' do
before do
@reserved = true
@book = Book.new(reserved: reserved)
@book.reserve
end
it 'returns falsey value' do
expect(@book.reserve).to be_falsey
end
end
end
Use let and before
RSpec.describe Book do
describe '#reserve' do
context 'when already reserved and the user reservation limit is exceeded' do
let(:reserved) { true }
let(:exceeded) { true }
# ...
end
context 'when already reserved and the users reservation limit is not exceeded' do
let(:reserved) { true }
let(:exceeded) { false }
# ...
end
context 'the book is available and the user reservation limit is exceeded' do
let(:reserved) { false }
let(:exceeded) { true }
# ...
end
context 'the book is available and the user has enough reservation limit' do
let(:reserved) { false }
let(:exceeded) { false }
# ...
end
end
end
Better
/PUGood
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(reserved: reserved) }
context 'when the book is already reserved' do
let(:reserved) { true }
it 'returns falsey value' do
is_expected.to be_falsey
end
end
end
end
#FUUFS
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RSpec.describe Book do
describe '#reserve' do
context 'when the book is already reserved' do
it 'returns falsey value' do
reserved = true
book = Book.new(reserved: reserved)
book.reserve
expect(book.reserved).to be_truthy
end
end
end
end
RSpec.describe Book do
describe '#reserve' do
before do
@reserved = true
@book = Book.new(reserved: reserved)
@book.reserve
end
it 'returns falsey value' do
expect(@book.reserve).to be_falsey
end
end
end
Use let and before
RSpec.describe Book do
describe '#reserve' do
context 'when already reserved and the user reservation limit is exceeded' do
let(:reserved) { true }
let(:exceeded) { true }
# ...
end
context 'when already reserved and the users reservation limit is not exceeded' do
let(:reserved) { true }
let(:exceeded) { false }
# ...
end
context 'the book is available and the user reservation limit is exceeded' do
let(:reserved) { false }
let(:exceeded) { true }
# ...
end
context 'the book is available and the user has enough reservation limit' do
let(:reserved) { false }
let(:exceeded) { false }
# ...
end
end
end
Better
/PUGood
#FUUFS
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(reserved: reserved) }
context 'when the book is already reserved' do
let(:reserved) { true }
it 'returns falsey value' do
is_expected.to be_falsey
end
end
end
end
DPOUFYUͱMFU͕ରԠ͍ͯͯ͠
ಡΈ͍͢
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Use subject and named subject
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Use subject and named subject
• ςετରͷΦϒδΣΫτϝιουΛsubjectͰ໌֬ʹ͢Δ
• ςετରʹ෭࡞༻͕͋Γɺͦͷ෭࡞༻Λςετ͢Δ߹
subjectʹ໊લΛ͚ͭͱಡΈ͘͢ͳΔ
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RSpec.describe Book do
describe '#reserve' do
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'returns truthy value' do
expect(book.reserve(user)).to be_truthy
end
it 'reserved user returns correct user' do
book.reserve(user)
expect(book.reserved_user).to eq user
end
end
end
Use subject and named subject
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'returns truthy value' do
is_expected.to be_truthy
end
it 'reserved user returns correct user' do
reserve_book
expect(book.reserved_user).to eq user
end
it 'number of books that the user reserved increases by 1' do
expect { reserve_book }.to change { user.reserved_books.count }.by(1)
end
end
end
Better
/PUGood
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RSpec.describe Book do
describe '#reserve' do
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'returns truthy value' do
expect(book.reserve(user)).to be_truthy
end
it 'reserved user returns correct user' do
book.reserve(user)
expect(book.reserved_user).to eq user
end
end
end
Use subject and named subject
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'returns truthy value' do
is_expected.to be_truthy
end
it 'reserved user returns correct user' do
reserve_book
expect(book.reserved_user).to eq user
end
it 'number of books that the user reserved increases by 1' do
expect { reserve_book }.to change { user.reserved_books.count }.by(1)
end
end
end
Better
/PUGood
/PUGood ςετओମ͕Θ͔ΓͮΒ͍
RSpec.describe Book do
describe '#reserve' do
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'returns truthy value' do
expect(book.reserve(user)).to be_truthy
end
it 'reserved user returns correct user' do
book.reserve(user)
expect(book.reserved_user).to eq user
end
end
end
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RSpec.describe Book do
describe '#reserve' do
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'returns truthy value' do
expect(book.reserve(user)).to be_truthy
end
it 'reserved user returns correct user' do
book.reserve(user)
expect(book.reserved_user).to eq user
end
end
end
Use subject and named subject
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'returns truthy value' do
is_expected.to be_truthy
end
it 'reserved user returns correct user' do
reserve_book
expect(book.reserved_user).to eq user
end
it 'number of books that the user reserved increases by 1' do
expect { reserve_book }.to change { user.reserved_books.count }.by(1)
end
end
end
Better
/PUGood
#FUUFS
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'returns truthy value' do
is_expected.to be_truthy
end
it 'reserved user returns correct user' do
subject
expect(book.reserved_user).to eq user
end
end
end
ςετओମ͕໌͔֬ͭ%3:
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RSpec.describe Book do
describe '#reserve' do
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'returns truthy value' do
expect(book.reserve(user)).to be_truthy
end
it 'reserved user returns correct user' do
book.reserve(user)
expect(book.reserved_user).to eq user
end
end
end
Use subject and named subject
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'returns truthy value' do
is_expected.to be_truthy
end
it 'reserved user returns correct user' do
reserve_book
expect(book.reserved_user).to eq user
end
it 'number of books that the user reserved increases by 1' do
expect { reserve_book }.to change { user.reserved_books.count }.by(1)
end
end
end
Better
/PUGood
#FUUFS✨
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'reserved user returns correct user' do
reserve_book
expect(book.reserved_user).to eq user
end
end
end
ओޠ͕ԿΛҙຯ͢Δͷ͔͕໌֬ʹͳΔ
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RSpec.describe Book do
describe '#reserve' do
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'returns truthy value' do
expect(book.reserve(user)).to be_truthy
end
it 'reserved user returns correct user' do
book.reserve(user)
expect(book.reserved_user).to eq user
end
end
end
Use subject and named subject
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'returns truthy value' do
is_expected.to be_truthy
end
it 'reserved user returns correct user' do
reserve_book
expect(book.reserved_user).to eq user
end
it 'number of books that the user reserved increases by 1' do
expect { reserve_book }.to change { user.reserved_books.count }.by(1)
end
end
end
Better
/PUGood
#FUUFS✨ DIBOHFFYQFDUBUJPOಛʹݟ͍͢
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new(reserved: false) }
let(:user) { User.new }
it 'number of books that the user reserved increases by 1' do
expect { reserve_book }.to change { user.reserved_books.count }.by(1)
end
end
end
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Reserved DRY
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Reserved DRY
• DRY(Don’t Repeat Yourself)߇͑Ίʹ͢Δ
• ੑʹΑΔมߋͷͮ͠Β͞ΑΓɺ
ಡΈʹ͘͞ͷํ͕ʹͳΔέʔε͕ଟ͍
• shared examplemacroΛ͏߹
ͦͷநԽʹΑͬͯಘΒΕͨͷͱՄಡੑͷόϥϯεΛߟ͑Δ͖
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RSpec.shared_examples 'reservation' do |decrease_by:, has_due_date:|
it "reserve the book and decrease remaining by -#{decrease_by}" do
expect { reserve_book }.to change { user.remaining_count }.by(-decrease_by)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be has_due_date
end
end
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new }
context 'when user has admin role' do
let(:user) { User.new(role: [:admin]) }
it_bahaves_like "reservation", decrease_by: 0, has_due_date: false
end
context 'when user has normal role' do
let(:user) { User.new(role: [:normal]) }
it_bahaves_like "reservation", decrease_by: 1, has_due_date: true
end
end
end
Reserved DRY
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new }
context 'when user has admin role' do
let(:user) { User.new(role: [:admin]) }
it "reserve and decrease remaining count and has no due date" do
expect { reserve_book }.not_to change { user.remaining_count }
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be_falsey
end
end
context 'when user has normal role' do
let(:user) { User.new(role: [:normal]) }
it "reserve and decrease remaining count and has no due date" do
expect { reserve_book }.to change { user.remaining_count }.by(1)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be_truthy
end
end
end
end
Better
/PUGood
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RSpec.shared_examples 'reservation' do |decrease_by:, has_due_date:|
it "reserve the book and decrease remaining by -#{decrease_by}" do
expect { reserve_book }.to change { user.remaining_count }.by(-decrease_by)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be has_due_date
end
end
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new }
context 'when user has admin role' do
let(:user) { User.new(role: [:admin]) }
it_bahaves_like "reservation", decrease_by: 0, has_due_date: false
end
context 'when user has normal role' do
let(:user) { User.new(role: [:normal]) }
it_bahaves_like "reservation", decrease_by: 1, has_due_date: true
end
end
end
Reserved DRY
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new }
context 'when user has admin role' do
let(:user) { User.new(role: [:admin]) }
it "reserve and decrease remaining count and has no due date" do
expect { reserve_book }.not_to change { user.remaining_count }
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be_falsey
end
end
context 'when user has normal role' do
let(:user) { User.new(role: [:normal]) }
it "reserve and decrease remaining count and has no due date" do
expect { reserve_book }.to change { user.remaining_count }.by(1)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be_truthy
end
end
end
end
Better
/PUGood
/PUGood ඞཁͳҾɺ͕݅Θ͔ΓͮΒ͍
RSpec.shared_examples 'reservation' do |decrease_by:, has_due_date:|
it "reserve the book and decrease remaining by -#{decrease_by}" do
expect { reserve_book }.to change { user.remaining_count }.by(-decrease_by)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be has_due_date
end
end
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RSpec.shared_examples 'reservation' do |decrease_by:, has_due_date:|
it "reserve the book and decrease remaining by -#{decrease_by}" do
expect { reserve_book }.to change { user.remaining_count }.by(-decrease_by)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be has_due_date
end
end
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new }
context 'when user has admin role' do
let(:user) { User.new(role: [:admin]) }
it_bahaves_like "reservation", decrease_by: 0, has_due_date: false
end
context 'when user has normal role' do
let(:user) { User.new(role: [:normal]) }
it_bahaves_like "reservation", decrease_by: 1, has_due_date: true
end
end
end
Reserved DRY
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new }
context 'when user has admin role' do
let(:user) { User.new(role: [:admin]) }
it "reserve and decrease remaining count and has no due date" do
expect { reserve_book }.not_to change { user.remaining_count }
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be_falsey
end
end
context 'when user has normal role' do
let(:user) { User.new(role: [:normal]) }
it "reserve and decrease remaining count and has no due date" do
expect { reserve_book }.to change { user.remaining_count }.by(1)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be_truthy
end
end
end
end
Better
/PUGood
/PUGood ඞཁͳҾɺ͕݅Θ͔ΓͮΒ͍
RSpec.shared_examples 'reservation' do |decrease_by:, has_due_date:|
it "reserve the book and decrease remaining by -#{decrease_by}" do
expect { reserve_book }.to change { user.remaining_count }.by(-decrease_by)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be has_due_date
end
end
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RSpec.shared_examples 'reservation' do |decrease_by:, has_due_date:|
it "reserve the book and decrease remaining by -#{decrease_by}" do
expect { reserve_book }.to change { user.remaining_count }.by(-decrease_by)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be has_due_date
end
end
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new }
context 'when user has admin role' do
let(:user) { User.new(role: [:admin]) }
it_bahaves_like "reservation", decrease_by: 0, has_due_date: false
end
context 'when user has normal role' do
let(:user) { User.new(role: [:normal]) }
it_bahaves_like "reservation", decrease_by: 1, has_due_date: true
end
end
end
Reserved DRY
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new }
context 'when user has admin role' do
let(:user) { User.new(role: [:admin]) }
it "reserve and decrease remaining count and has no due date" do
expect { reserve_book }.not_to change { user.remaining_count }
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be_falsey
end
end
context 'when user has normal role' do
let(:user) { User.new(role: [:normal]) }
it "reserve and decrease remaining count and has no due date" do
expect { reserve_book }.to change { user.remaining_count }.by(1)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be_truthy
end
end
end
end
Better
/PUGood
/PUGood ඞཁͳҾɺ͕݅Θ͔ΓͮΒ͍
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new }
context 'when user has admin role' do
let(:user) { User.new(role: [:admin]) }
it_bahaves_like "reservation", decrease_by: 0, has_due_date: false
end
context 'when user has normal role' do
let(:user) { User.new(role: [:normal]) }
it_bahaves_like "reservation", decrease_by: 1, has_due_date: true
end
end
end
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RSpec.shared_examples 'reservation' do |decrease_by:, has_due_date:|
it "reserve the book and decrease remaining by -#{decrease_by}" do
expect { reserve_book }.to change { user.remaining_count }.by(-decrease_by)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be has_due_date
end
end
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new }
context 'when user has admin role' do
let(:user) { User.new(role: [:admin]) }
it_bahaves_like "reservation", decrease_by: 0, has_due_date: false
end
context 'when user has normal role' do
let(:user) { User.new(role: [:normal]) }
it_bahaves_like "reservation", decrease_by: 1, has_due_date: true
end
end
end
Reserved DRY
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new }
context 'when user has admin role' do
let(:user) { User.new(role: [:admin]) }
it "reserve and decrease remaining count and has no due date" do
expect { reserve_book }.not_to change { user.remaining_count }
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be_falsey
end
end
context 'when user has normal role' do
let(:user) { User.new(role: [:normal]) }
it "reserve and decrease remaining count and has no due date" do
expect { reserve_book }.to change { user.remaining_count }.by(1)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be_truthy
end
end
end
end
Better
/PUGood
#FUUFS ʹॻ͍ͨ΄͏͕ඞཁͳ݅ظ͕͔Γ͍͢
RSpec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve }
let(:book) { Book.new }
context 'when user has admin role' do
let(:user) { User.new(role: [:admin]) }
it "reserve and decrease remaining count and has no due date" do
expect { reserve_book }.not_to change { user.remaining_count }
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be_falsey
end
end
context 'when user has normal role' do
let(:user) { User.new(role: [:normal]) }
it "reserve and decrease remaining count and has no due date" do
expect { reserve_book }.to change { user.remaining_count }.by(1)
expect(book.reserved_user).to eq user
expect(book.reservation.due_date.present?).to be_truthy
end
end
end
end
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Expect change
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Expect change
• ʮมߋʯʹ͍ͭͯςετΛ͢Δ߹ɺexpect changeΛ͏
• ෭࡞༻ʹ͍ͭͯςετ͍ͯ͠Δ͜ͱ͕໌֬ʹͳΔ
• expect changeΛΘͳ͍߹ɺҙਤͤͣલఏ͕յΕͯ͠·͏Մೳੑ͕͋Δ
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Rspec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve(user) }
let!(:user) { User.new(remaining_count: 3) }
it 'decrease remaining count by 1' do
reserve_book
expect(user.remaining_count).to eq 2
end
end
end
Expect change
Rspec.describe Book do
describe '#reserve' do
subject(:reserve_book) { book.reserve(user) }
let!(:user) { User.new(remaining_count: 3) }
it 'decrease remaining count by 1' do
expect { reserve_book }.to change { user.remaining_count }.by(-1)
end
end
end
Better
/PUGood
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Should not update context value
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Should not update context value
• contextͷதͰbeforeletͰࣄલʹఆٛͨ͠Λߋ৽͠ͳ͍
• ࠷ऴతͳΛѲ͢Δͷ͕͘͠ͳΔ
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# Case 1
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: true) }
context 'when the book is not available' do
before do
book.update(available: false)
end
# ...
end
end
end
# Case 2
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: available, country: country) }
let(:available) { true }
let(:country) { :jp }
context 'when the book is not available' do
let(:available) { false }
# ...
end
end
end
Should not update context value
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: available, country: :jp) }
context 'when the book is not available' do
let(:available) { false }
# ...
end
end
end
Better
/PUGood
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# Case 1
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: true) }
context 'when the book is not available' do
before do
book.update(available: false)
end
# ...
end
end
end
# Case 2
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: available, country: country) }
let(:available) { true }
let(:country) { :jp }
context 'when the book is not available' do
let(:available) { false }
# ...
end
end
end
Should not update context value
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: available, country: :jp) }
context 'when the book is not available' do
let(:available) { false }
# ...
end
end
end
Better
/PUGood
/PUGood ͦͷ$POUFYUͰͷ࠷ऴతͳΛཧղͮ͠Β͘ͳΔ
# Case 1
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: true) }
context 'when the book is not available' do
before do
book.update(available: false)
end
# ...
end
end
end
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# Case 1
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: true) }
context 'when the book is not available' do
before do
book.update(available: false)
end
# ...
end
end
end
# Case 2
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: available, country: country) }
let(:available) { true }
let(:country) { :jp }
context 'when the book is not available' do
let(:available) { false }
# ...
end
end
end
Should not update context value
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: available, country: :jp) }
context 'when the book is not available' do
let(:available) { false }
# ...
end
end
end
Better
/PUGood
/PUGood MFUͰ্ॻ͖͢Δ߹ಉ͕͡ى͖Δ
# Case 2
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: available, country: country) }
let(:available) { true }
let(:country) { :jp }
context 'when the book is not available' do
let(:available) { false }
# ...
end
end
end
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# Case 1
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: true) }
context 'when the book is not available' do
before do
book.update(available: false)
end
# ...
end
end
end
# Case 2
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: available, country: country) }
let(:available) { true }
let(:country) { :jp }
context 'when the book is not available' do
let(:available) { false }
# ...
end
end
end
Should not update context value
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: available, country: :jp) }
context 'when the book is not available' do
let(:available) { false }
# ...
end
end
end
Better
/PUGood
#FUUFS DPOUFYUͰࢦఆ͢ΔσϑΥϧτΛઃఆ͠ͳ͍
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: available, country: :jp) }
context 'when the book is not available' do
let(:available) { false }
# ...
end
end
end
Slide 50
Slide 50 text
Write expectations
at a high level
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Slide 51 text
Write expectations at a high level
• contextexampleͷઆ໌ίʔυϨϕϧͷઆ໌Ͱͳ͘ɺ
ΑΓߴڃతͳઆ໌Λॻ͘
• ίʔυϨϕϧͷઆ໌contextϒϩοΫͷletbeforeΛݟΕ͔Δ
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Slide 52 text
Write expectations at a high level
Better
/PUGood
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: available) }
context 'when book.available == false' do
let(:available) { false }
# ...
end
end
end
RSpec.describe Book do
describe '#reserve' do
subject { book.reserve }
let(:book) { Book.new(available: available) }
context 'when the book can be reserved' do
let(:available) { false }
# ...
end
end
end
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Slide 53 text
Should not use “should”
in example names
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Slide 54 text
Should not use “should” in example names
• exampleͷઆ໌ʹshouldΛΘͣɺݴ͍Δ
• ݴ͍Γେࣄ
• ʮόά͕͋Γ·͕ͨ͠ɺ͏͋Γ·ͤΜʯ by tumblr
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Slide 55 text
it 'is reserved'
it 'should be reserved'
Should not use “should” in example names
Better
/PUGood
Slide 56
Slide 56 text
Summary
* Describe and context
* Use single-level contexts
* Use let and before
* Use subject and named subject
* Reserved DRY
* Expect change
* Should not update context value
* Write expectations at a high level
* Should not use "should" in our example names
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Slide 57 text
·ͩ·ͩ͋Γ·͕͢ɺ
Ұ൪جຊͦ͏ͳͱ͜ΖΛ
·ͱΊ·ͨ͠ʂ
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Slide 58 text
օ͞Μ͕࣮ફ͍ͯ͠Δ
ಡΈ͍͢ॻ͖ํ
ੋඇڭ͍͑ͯͩ͘͞ʂ
Slide 59
Slide 59 text
Happy testing