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|
Feature: Send
Takes a variable number of method names as symbols. Given an argument, all of
those methods are called on the argument one by one. If they all return true,
the contract passes.
```ruby
Contract C::Send[:valid?, :has_items?] => C::ArrayOf[Item]
```
This contract will pass only if:
`arg.valid? == true && arg.has_items? == true`,
where `arg` is the first argument.
Background:
Given a file named "item.rb" with:
"""ruby
Item = Struct.new(:name, :cost)
Item::DEFAULT = Item["default", 0]
"""
Given a file named "send_usage.rb" with:
"""ruby
require "contracts"
C = Contracts
require "./item"
class FetchItemCommand
include Contracts::Core
Contract C::Send[:valid?, :has_items?] => C::ArrayOf[Item]
def call(subject)
([Item::DEFAULT] + subject.items).uniq
end
end
"""
Scenario: All methods return `true`
Given a file named "box.rb" with:
"""ruby
class Box
def valid?
true
end
def has_items?
true
end
def items
[Item["cat", 599.99]]
end
end
require "./send_usage"
p FetchItemCommand.new.call(Box.new)
"""
When I run `ruby box.rb`
Then output should contain:
"""
[#<struct Item name="default", cost=0>, #<struct Item name="cat", cost=599.99>]
"""
Scenario: When second method returns `false`
Given a file named "cat.rb" with:
"""ruby
class Cat
def valid?
true
end
def has_items?
false
end
end
require "./send_usage"
p FetchItemCommand.new.call(Cat.new)
"""
When I run `ruby cat.rb`
Then output should contain:
"""
: Contract violation for argument 1 of 1: (ParamContractError)
Expected: (a value that returns true for all of [:valid?, :has_items?]),
"""
And output should contain:
"""
Actual: #<Cat
"""
Scenario: When first method returns `false`
Given a file named "invalid.rb" with:
"""ruby
class Invalid
def valid?
false
end
def has_items?
true
end
def items
[]
end
end
require "./send_usage"
p FetchItemCommand.new.call(Invalid.new)
"""
When I run `ruby invalid.rb`
Then output should contain:
"""
: Contract violation for argument 1 of 1: (ParamContractError)
Expected: (a value that returns true for all of [:valid?, :has_items?]),
"""
And output should contain:
"""
Actual: #<Invalid
"""
Scenario: When all methods return `false`
Given a file named "nothing.rb" with:
"""ruby
class Nothing
def valid?
false
end
def has_items?
false
end
end
require "./send_usage"
p FetchItemCommand.new.call(Nothing.new)
"""
When I run `ruby nothing.rb`
Then output should contain:
"""
: Contract violation for argument 1 of 1: (ParamContractError)
Expected: (a value that returns true for all of [:valid?, :has_items?]),
"""
And output should contain:
"""
Actual: #<Nothing
"""
|
