Merge pull request #30 from michaelherold/add-i18n-support

Add I18n configuration support

CHANGELOG.md

@@ -9,6 +9,7 @@ All notable changes to this project will be documented in this file. This projec
 ### Added
 
 * [#27](https://github.com/michaelherold/interactor-contracts/pull/27): Upgrade dry-validation to 1.0 - [@vaihtovirta](https://github.com/vaihtovirta).
+* [#30](https://github.com/michaelherold/interactor-contracts/pull/30): Allow setting a custom I18n backend for contract messages - [@michaelherold](https://github.com/michaelherold).
 
 ### Changed
 

Gemfile

@@ -19,6 +19,7 @@ group :development do
 end
 
 group :development, :test do
+  gem 'i18n'
   gem 'pry'
   gem 'rake', '< 11'
 end

README.md

@@ -103,6 +103,36 @@ result.failure?  #=> true
 
 [dry-validation]: https://github.com/dryrb/dry-validation
 
+### I18n support
+
+You can [configure the underlying `dry-validation` contract][config] by passing
+a block to the `config` method in your contract. This block will be evaluated on
+the underlying configuration for the contract. For example, if you want to set
+up the contract to use I18n in your Rails app, you might do something like this:
+
+```ruby
+class MyInteractor
+  include Interactor
+  include Interactor::Contracts
+
+  config do
+    messages.backend = :i18n
+    messages.load_paths << Rails.root / 'config' / 'locales' / 'errors.yml'
+    messages.top_namespace = :interactor_contracts
+  end
+end
+```
+
+This sets up the I18n system (assuming the delicate load-order has been done in
+the right way - you have to require `i18n` prior to requiring
+`interactor-contracts` since we load `dry-validation` immediately) to use your
+custom file. All lookups for error messages happen starting at the
+`interactor_contracts` key in this example.
+
+See [the documentation for `dry-validation`][config] for more information.
+
+[config]: https://dry-rb.org/gems/dry-validation/1.0/configuration/
+
 ## Development
 
 After checking out the repo, run `bin/setup` to install dependencies. Then, run

lib/interactor/contracts/contract.rb

@@ -89,6 +89,16 @@ def add_expectation(&term)
         expectations.add(&term)
       end
 
+      # Configures the underlying contracts for the validation schemata
+      #
+      # @api private
+      # @private
+      # @return [void]
+      def config(&block)
+        promises.config(&block)
+        expectations.config(&block)
+      end
+
       # The consequences for the Contract
       #
       # @example

lib/interactor/contracts/dsl.rb

@@ -31,6 +31,27 @@ def promises(&block)
       end
       alias assures promises
 
+      # Sends configuration set up to the underlying contracts in the terms
+      #
+      # @example
+      #   class CreatePerson
+      #     include Interactor
+      #     include Interactor::Contracts
+      #
+      #     config do
+      #       messages.backend = :i18n
+      #       messages.top_namespace = :my_app
+      #       messages.load_paths << File.join(__dir__, '..', 'errors.yml')
+      #     end
+      #   end
+      #
+      # @api public
+      # @params [Block] block the block to execute for the underlying contracts
+      # @return [void]
+      def config(&block)
+        contract.config(&block)
+      end
+
       # The Contract to enforce on calls to the Interactor
       #
       # @example

lib/interactor/contracts/terms.rb

@@ -30,6 +30,10 @@ def initialize(terms = Class.new(Dry::Validation::Contract))
       # @return [void]
       def add(&term)
         @terms = Class.new(Dry::Validation::Contract).tap do |new_terms|
+          new_terms.instance_variable_set(
+            :@config,
+            @terms.instance_variable_get(:@config).dup
+          )
           new_terms.params(@terms.schema, &term)
         end
       end
@@ -52,6 +56,15 @@ def call(context)
         Outcome.new(@terms.new.call(context.to_h))
       end
 
+      # Configures the underlying contracts within the terms
+      #
+      # @api private
+      # @private
+      # @return [void]
+      def config(&block)
+        @terms.config.instance_exec(&block)
+      end
+
       private
 
       # Defines no-op rules block if no schema has been added

spec/interactor/contracts/dsl_spec.rb

@@ -3,6 +3,40 @@
 require 'spec_helper'
 
 RSpec.describe Interactor::Contracts::DSL do
+  describe '.config' do
+    it 'allows you to configure the messaging for the contracts' do
+      require 'i18n'
+      require 'dry/schema/messages/i18n'
+
+      klass = Class.new do
+        include Interactor
+        include Interactor::Contracts
+
+        config do
+          messages.backend = :i18n
+          messages.top_namespace = :my_app
+          messages.load_paths << File.expand_path(
+            File.join('..', '..', 'support', 'errors.yml'),
+            __dir__
+          )
+        end
+
+        expects do
+          required(:bar).filled
+        end
+
+        on_breach do |breaches|
+          context.fail!(message: breaches.to_h)
+        end
+      end
+
+      result = klass.call
+
+      expect(result).to be_a_failure
+      expect(result.message).to eq(bar: ['bar is foobared'])
+    end
+  end
+
   describe '.expects' do
     subject(:interactor_call) { klass.call(context) }
 

spec/support/errors.yml

@@ -0,0 +1,4 @@
+en:
+  my_app:
+    errors:
+      key?: 'is foobared'