Usage of dry-types in cooperation with dry-validation. To execute run `ruby dry_validation_spec.rb`

dry_validation_spec.rb

require 'bundler/inline'

gemfile do
  source 'https://rubygems.org'
  gem 'dry-validation', '1.4.2'
  gem 'rspec', '3.9.0'
end

require 'dry-validation'

module Types
  include Dry::Types(default: :nominal)
  URL_REGEX = /\Awww\.(.*)\z/

  ConstrainedUrl = String.constrained(format: URL_REGEX)

  ConstructorUrl = String.constructor do |input, &block|
    if input.match?(URL_REGEX)
      input
    elsif block
      block.call
    else
      raise Dry::Types::ConstraintError.new("format?(#{URL_REGEX.inspect}, #{input.inspect})", input)
    end
  end
end

RSpec.describe 'Passing errors from dry-types to dry-validation', :aggregate_failures do
  let(:valid_url) { 'www.wp.pl' }
  let(:invalid_url) { 'wp.pl' }

  describe 'Types definitions' do
    shared_examples 'dry-type interface' do |type|
      describe "Type: #{type}" do
        context 'with invalid input' do
          let(:url) { invalid_url }

          it 'Throws Dry::Types::ConstraintError' do
            expect { type.call(url) }
              .to raise_error(Dry::Types::ConstraintError, "#{url.inspect} violates constraints (format?(/\\Awww\\.(.*)\\z/, #{url.inspect}) failed)")
          end

          context 'with block provided to the type' do
            let(:fallback) { :invalid }

            it 'returns fallback value' do
              expect(type.call(url) { fallback }).to eq(fallback)
            end
          end
        end

        context 'with valid input' do
          let(:url) { valid_url }

          it 'returns the input' do
            expect(type.call(url)).to eq(url)
          end

          context 'with a block provided to the type' do
            let(:fallback) { :invalid }

            it 'returns the input' do
              expect(type.call(url) { fallback }).to eq(url)
            end
          end
        end
      end
    end

    it_behaves_like 'dry-type interface', Types::ConstrainedUrl
    it_behaves_like 'dry-type interface', Types::ConstructorUrl
  end

  describe 'Validation::Contract definition' do
    shared_examples 'contract with typed input' do |type|
      describe "Type: #{type}" do
        subject(:result) { contract.call(url: url) }

        let(:contract) do
          Class.new(Dry::Validation::Contract) do
            params do
              required(:url).value(type)
            end
          end.new
        end

        context 'with invalid url' do
          let(:url) { invalid_url }

          it { is_expected.to_not be_success }

          it 'returns errors' do
            expect(result.errors.to_h).to eq(
              url: ['is in invalid format']
            )
          end
        end

        context 'with valid url' do
          let(:url) { valid_url }

          it { is_expected.to be_success }

          it 'returns no errors' do
            expect(result.errors).to be_empty
          end
        end
      end
    end

    it_behaves_like 'contract with typed input', Types::ConstrainedUrl
    it_behaves_like 'contract with typed input', Types::ConstructorUrl
  end
end

RSpec::Core::Runner.run(['spec', '--format', 'doc'])


# $ ruby dry_validation_spec.rb
# 
# Passing errors from dry-types to dry-validation
#   Types definitions
#     behaves like dry-type interface
#       Type: #<Dry::Types[Constrained<Nominal<String> rule=[format?(/\Awww\.(.*)\z/)]>]>
#         with invalid input
#           Throws Dry::Types::ConstraintError
#           with block provided to the type
#             returns fallback value
#         with valid input
#           returns the input
#           with a block provided to the type
#             returns the input
#     behaves like dry-type interface
#       Type: #<Dry::Types[Constructor<Nominal<String> fn=dry_validation_spec.rb:17>]>
#         with invalid input
#           Throws Dry::Types::ConstraintError
#           with block provided to the type
#             returns fallback value
#         with valid input
#           returns the input
#           with a block provided to the type
#             returns the input
#   Validation::Contract definition
#     behaves like contract with typed input
#       Type: #<Dry::Types[Constrained<Nominal<String> rule=[format?(/\Awww\.(.*)\z/)]>]>
#         with invalid url
#           is expected not to be success
#           returns errors
#         with valid url
#           is expected to be success
#           returns no errors
#     behaves like contract with typed input
#       Type: #<Dry::Types[Constructor<Nominal<String> fn=dry_validation_spec.rb:17>]>
#         with invalid url
#           is expected not to be success (FAILED - 1)
#           returns errors (FAILED - 2)
#         with valid url
#           is expected to be success
#           returns no errors
# 
# Failures:
# 
#   1) Passing errors from dry-types to dry-validation Validation::Contract definition behaves like contract with typed input Type: #<Dry::Types[Constructor<Nominal<String> fn=dry_validation_spec.rb:17>]> with invalid url is expected not to be success
#      Failure/Error: it { is_expected.to_not be_success }
#        expected `#<Dry::Validation::Result{:url=>"wp.pl"} errors={}>.success?` to return false, got true
#      Shared Example Group: "contract with typed input" called from dry_validation_spec.rb:112
#      # dry_validation_spec.rb:90:in `block (6 levels) in <main>'
#      # dry_validation_spec.rb:116:in `<main>'
# 
#   2) Passing errors from dry-types to dry-validation Validation::Contract definition behaves like contract with typed input Type: #<Dry::Types[Constructor<Nominal<String> fn=dry_validation_spec.rb:17>]> with invalid url returns errors
#      Failure/Error:
#        expect(result.errors.to_h).to eq(
#          url: ['is in invalid format']
#        )
#      
#        expected: {:url=>["is in invalid format"]}
#             got: {}
#      
#        (compared using ==)
#      
#        Diff:
#        @@ -1,2 +1 @@
#        -:url => ["is in invalid format"],
#        
#      Shared Example Group: "contract with typed input" called from dry_validation_spec.rb:112
#      # dry_validation_spec.rb:93:in `block (6 levels) in <main>'
#      # dry_validation_spec.rb:116:in `<main>'
# 
# Finished in 0.04198 seconds (files took 0.08128 seconds to load)
# 16 examples, 2 failures
# 
# Failed examples:
# 
# rspec 'dry_validation_spec.rb[1:2:2:1:1:1]' # Passing errors from dry-types to dry-validation Validation::Contract definition behaves like contract with typed input Type: #<Dry::Types[Constructor<Nominal<String> fn=dry_validation_spec.rb:17>]> with invalid url is expected not to be success
# rspec 'dry_validation_spec.rb[1:2:2:1:1:2]' # Passing errors from dry-types to dry-validation Validation::Contract definition behaves like contract with typed input Type: #<Dry::Types[Constructor<Nominal<String> fn=dry_validation_spec.rb:17>]> with invalid url returns errors