TSpec

TSpec adds a method of simple type check to Ruby.

🚧 Recommended for use only in hobby programming. Do not use this in production apps. 🚧

Installation

Add this line to your application's Gemfile:

gem 'tspec'

And then execute:

$ bundle

Or install it by yourself:

$ gem install tspec

Usage

TSpec can use #receive and #return method.

receive

receive defines the type of method arguments.

require 'tspec'

def echo(str)
  puts str
end.receive(str: String)

echo('hello world') #=> ok
echo(123)           #=> TSpec::ArgumentTypeError

You can specify multiple type, too.

require 'tspec'

def echo(val)
  puts val
end.receive(val: [String, Float])

echo('hello')  #=> ok
echo(3.14)     #=> ok
echo(123)      #=> TSpec::ArgumentTypeError

If single method argument is given, you can skip keyword.

require 'tspec'

def join_array(arr)
  arr.join(' ')
end.receive([String])

puts join_array(%w(hello world)) #=> ok
puts join_array([1,2,3])         #=> TSpec::ArgumentTypeError

You can specify Array content type, although it may seem strange.

require 'tspec'

def receive_string_array(arr)
  arr.join
end.receive(arr: [[String]])

puts receive_string_array(['hello', 'world']) #=> ok
puts receive_string_array([:hello, :world])   #=> TSpec::ArgumentTypeError

return

return defines the type of method return value.

require 'tspec'

def message
  'hello world'
end.return(String)

def dummy_message
  'hello world'
end.return(Symbol)

puts message        #=> ok
puts dummy_message  #=> TSpec::ReturnValueTypeError

You can specify multiple return value, too.

require 'tspec'

def random_val
  [1.0, '1', :hello].sample
end.return(Float, String, Symbol)

10.times do
  v = random_val
end

Also, you can specify Array content type.

require 'tspec'

def message_list
  %w(hello ruby world)
end.return([String])

p message_list

Example

Combination of receive and return method.

require 'tspec'

def string2symbol(str)
  str.to_sym
end.receive(str: String).return(Symbol)

p string2symbol('hello')  #=> :hello
p string2symbol(123)      #=> TSpec::ArgumentTypeError

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/siman-man/tspec. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available under the terms of the MIT License.

tspec

Development