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|
RSpec.describe Contract do
describe ".override_validator" do
around do |example|
Contract.reset_validators
example.run
Contract.reset_validators
end
it "allows to override simple validators" do
Contract.override_validator(Hash) do |contract|
lambda do |arg|
return false unless arg.is_a?(Hash)
# Any hash in my system should have :it_is_a_hash key!
return false unless arg.key?(:it_is_a_hash)
contract.keys.all? do |k|
Contract.valid?(arg[k], contract[k])
end
end
end
klass = Class.new do
include Contracts::Core
Contract ({ :a => Contracts::Num, :b => String }) => nil
def something(opts)
nil
end
end
obj = klass.new
expect do
obj.something({ :a => 35, :b => "hello" })
end.to raise_error(ContractError)
expect do
obj.something({
:a => 35,
:b => "hello",
:it_is_a_hash => true
})
end.not_to raise_error
end
it "allows to override valid contract" do
Contract.override_validator(:valid) do |contract|
if contract.respond_to?(:in_valid_state?)
lambda do |arg|
contract.in_valid_state? && contract.valid?(arg)
end
else
lambda { |arg| contract.valid?(arg) }
end
end
stateful_contract = Class.new(Contracts::CallableClass) do
def initialize(contract)
@contract = contract
@state = 0
end
def in_valid_state?
@state < 3
end
def valid?(arg)
@state += 1
Contract.valid?(arg, @contract)
end
end
klass = Class.new do
include Contracts::Core
Contract stateful_contract[Contracts::Num] => Contracts::Num
def only_three_times(x)
x * x
end
end
obj = klass.new
expect(obj.only_three_times(3)).to eq(9)
expect(obj.only_three_times(3)).to eq(9)
expect(obj.only_three_times(3)).to eq(9)
expect do
obj.only_three_times(3)
end.to raise_error(ContractError)
expect do
obj.only_three_times(3)
end.to raise_error(ContractError)
end
it "allows to override class validator" do
# Make contracts accept all rspec doubles
Contract.override_validator(:class) do |contract|
lambda do |arg|
arg.is_a?(RSpec::Mocks::Double) ||
arg.is_a?(contract)
end
end
klass = Class.new do
include Contracts::Core
Contract String => String
def greet(name)
"hello, #{name}"
end
end
obj = klass.new
expect(obj.greet("world")).to eq("hello, world")
expect do
obj.greet(4)
end.to raise_error(ContractError)
expect(obj.greet(double("name"))).to match(
/hello, #\[.*Double.*"name"\]/
)
end
it "allows to override default validator" do
spy = double("spy")
Contract.override_validator(:default) do |contract|
lambda do |arg|
spy.log("#{arg} == #{contract}")
arg == contract
end
end
klass = Class.new do
include Contracts::Core
Contract 1, Contracts::Num => Contracts::Num
def gcd(_, b)
b
end
Contract Contracts::Num, Contracts::Num => Contracts::Num
def gcd(a, b)
gcd(b % a, a)
end
end
obj = klass.new
expect(spy).to receive(:log).with("8 == 1").ordered.once
expect(spy).to receive(:log).with("5 == 1").ordered.once
expect(spy).to receive(:log).with("3 == 1").ordered.once
expect(spy).to receive(:log).with("2 == 1").ordered.once
expect(spy).to receive(:log).with("1 == 1").ordered.once
obj.gcd(8, 5)
end
end
end
|
