Moguro

gem 'moguro'

require 'moguro'

class MockClass
  include Moguro::Decorator
  
  # Must match argument names of decorate method
  pre_c ->(a: Integer, b: String) {
    assert_equal(a, 1)
    assert_equal(b, 'b')
  }
 
  def puts_method(a, b)
    puts b
    a + 1
  end
  
  # Return values are auto assigned in order
  post_c -> (first: String) {
    p first
  }
  def post_contract_violation_method
    1
  end
  
end

c = MockClass.new
c.puts_method(1, 'b')
# 1
# => 2

begin 
  c.puts_method('a', 1)
rescue => e
  p e
end
# =>
# Type MissMatch: a is expected (Integer) actual a(String) (Moguro::Errors::ArgumentsTypeMismatchError)
# Expected: [a: (Integer), b: (String)]
# Actual: [a: a(String), b: 1(Integer)]
# Value guarded in: MockClass::puts_method
# At: #{source_location}

begin
  c.post_contract_violation_method
rescue => e
  p e
end

# =>
# Type MissMatch: first is expected (String) actual 1(Integer)
#  Expected: [first: (String)]
#  Actual: [first: 1(Integer)]
#  Value guarded in: MockClass::post_contract_violation_method
#  At: #{source_location}