Add dry-validation contract support (#238)

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### New features
+
+* Add dry-validation contract support ([#238](https://github.com/railsconfig/config/pull/238))
+
 ### Changes
 
 * Get rid of activesupport dependency ([#230](https://github.com/railsconfig/config/pull/230))

README.md

@@ -292,26 +292,59 @@ Check [Deep Merge](https://github.com/danielsdeleo/deep_merge) for more details.
 
 ### Validation
 
-With Ruby 2.1 or newer, you can optionally define a schema to validate presence (and type) of specific config values:
+With Ruby 2.1 or newer, you can optionally define a [schema](https://github.com/dry-rb/dry-schema) or [contract](https://github.com/dry-rb/dry-validation) (added in `config-2.1`) using [dry-rb](https://github.com/dry-rb) to validate presence (and type) of specific config values. Generally speaking contracts allow to describe more complex validations with depencecies between fields.
+
+If you provide either validation option (or both) it will automatically be used to validate your config. If validation fails it will raise a `Config::Validation::Error` containing information about all the mismatches between the schema and your config.
+
+Both examples below demonstrates how to ensure that the configuration has an optional `email` and the `youtube` structure with the `api_key` field filled. The contract adds an additional rule.
+
+#### Contract
+
+Leverage dry-validation, you can create a contract with a params schema and rules:
+
+```ruby
+class ConfigContract < Dry::Validation::Contract
+  params do
+    optional(:email).maybe(:str?)
+
+    required(:youtube).schema do
+      required(:api_key).filled
+    end
+  end
+
+  rule(:email) do
+    unless /\A[\w+\-.]+@[a-z\d\-]+(\.[a-z\d\-]+)*\.[a-z]+\z/i.match?(value)
+      key.failure('has invalid format')
+    end
+  end
+end
+
+Config.setup do |config|
+  config.validation_contract = ConfigContract
+end
+```
+
+The above example adds a rule to ensure the `email` is valid by matching it against the provided regular expression.
+
+Check [dry-validation](https://github.com/dry-rb/dry-validation) for more details.
+
+#### Schema
+
+You may also specify a schema using [dry-schema](https://github.com/dry-rb/dry-schema):
 
 ```ruby
 Config.setup do |config|
   # ...
   config.schema do
+    optional(:email).maybe(:str?)
+
     required(:youtube).schema do
       required(:api_key).filled
     end
   end
 end
 ```
 
-The above example demonstrates how to ensure that the configuration has the `youtube` structure
-with the `api_key` field filled.
-
-If you define a schema it will automatically be used to validate your config. If validation fails it will
-raise a `Config::Validation::Error` containing a nice message with information about all the mismatches
-between the schema and your config.
-
 Check [dry-schema](https://github.com/dry-rb/dry-schema) for more details.
 
 ### Missing keys

config.gemspec

@@ -28,7 +28,7 @@ Please consider donating to our open collective to help us maintain this project
   s.required_ruby_version = '>= 2.4.0'
 
   s.add_dependency 'deep_merge', '~> 1.2', '>= 1.2.1'
-  s.add_dependency 'dry-schema', '~> 1.0'
+  s.add_dependency 'dry-validation', '~> 1.0'
 
   s.add_development_dependency 'rake', '~> 12.0', '>= 12.0.0'
 

lib/config.rb

@@ -1,3 +1,4 @@
+require 'dry-validation'
 require 'config/compatibility'
 require 'config/options'
 require 'config/configuration'
@@ -23,7 +24,8 @@ module Config
     knockout_prefix: nil,
     merge_nil_values: true,
     overwrite_arrays: true,
-    merge_hash_arrays: false
+    merge_hash_arrays: false,
+    validation_contract: nil
   )
 
   def self.setup

lib/config/validation/schema.rb

@@ -1,5 +1,3 @@
-require 'dry-schema'
-
 module Config
   module Validation
     module Schema

lib/config/validation/validate.rb

@@ -3,18 +3,23 @@
 module Config
   module Validation
     module Validate
-
       def validate!
-        if Config.schema
-          v_res = Config.schema.(self.to_hash)
+        validate_using!(Config.validation_contract)
+        validate_using!(Config.schema)
+      end
+
+      private
 
-          unless v_res.success?
-            error = Config::Validation::Error.format(v_res)
-            raise Config::Validation::Error.new("Config validation failed:\n\n#{error}")
-          end
+      def validate_using!(validator)
+        if validator
+          result = validator.call(to_hash)
+
+          return if result.success?
+
+          error = Config::Validation::Error.format(result)
+          raise Config::Validation::Error, "Config validation failed:\n\n#{error}"
         end
       end
-
     end
   end
 end

spec/spec_helper.rb

@@ -72,11 +72,12 @@
 
       # Extend Config module with ability to reset configuration to the default values
       def self.reset
-        self.const_name       = 'Settings'
-        self.use_env          = false
-        self.knockout_prefix  = nil
-        self.overwrite_arrays = true
-        self.schema           = nil
+        self.const_name           = 'Settings'
+        self.use_env              = false
+        self.knockout_prefix      = nil
+        self.overwrite_arrays     = true
+        self.schema               = nil
+        self.validation_contract  = nil
         instance_variable_set(:@_ran_once, false)
       end
     end

spec/validation_spec.rb

@@ -8,35 +8,74 @@
       Config.reset
     end
 
-    it 'should raise if schema is present and validation fails' do
-      Config.setup do |config|
-        config.schema do
+    context 'with validation_contract' do
+      it 'should raise if validation_contract is present and validation fails' do
+        contract = Class.new(Dry::Validation::Contract)
+        contract.params do
           required(:youtube).schema do
             required(:nonexist_field).filled
             required(:multiple_requirements).filled(:integer, gt?: 18)
           end
         end
-      end
+        Config.setup do |config|
+          config.validation_contract = contract.new
+        end
 
-      msg = "Config validation failed:\n\n"
-      msg += "  youtube.nonexist_field: is missing\n"
-      msg += '  youtube.multiple_requirements: must be an integer'
+        msg = "Config validation failed:\n\n"
+        msg += "  youtube.nonexist_field: is missing\n"
+        msg += '  youtube.multiple_requirements: must be an integer'
 
-      expect { Config.load_files("#{fixture_path}/validation/config.yml") }.
-        to raise_error(Config::Validation::Error, Regexp.new(msg))
-    end
+        expect { Config.load_files("#{fixture_path}/validation/config.yml") }.
+          to raise_error(Config::Validation::Error, Regexp.new(msg))
+      end
 
-    it 'should work if validation passes' do
-      Config.setup do |config|
-        config.schema do
+      it 'should work if validation passes' do
+        contract = Class.new(Dry::Validation::Contract)
+        contract.params do
           required(:youtube).schema do
             required(:api_key).filled
           end
         end
+        Config.setup do |config|
+          config.validation_contract = contract.new
+        end
+
+        expect { Config.load_files("#{fixture_path}/validation/config.yml") }.
+          to_not raise_error
       end
+    end
 
-      expect { Config.load_files("#{fixture_path}/validation/config.yml") }.
-        to_not raise_error
+    context 'with schema' do
+      it 'should raise if schema is present and validation fails' do
+        Config.setup do |config|
+          config.schema do
+            required(:youtube).schema do
+              required(:nonexist_field).filled
+              required(:multiple_requirements).filled(:integer, gt?: 18)
+            end
+          end
+        end
+
+        msg = "Config validation failed:\n\n"
+        msg += "  youtube.nonexist_field: is missing\n"
+        msg += '  youtube.multiple_requirements: must be an integer'
+
+        expect { Config.load_files("#{fixture_path}/validation/config.yml") }.
+          to raise_error(Config::Validation::Error, Regexp.new(msg))
+      end
+
+      it 'should work if validation passes' do
+        Config.setup do |config|
+          config.schema do
+            required(:youtube).schema do
+              required(:api_key).filled
+            end
+          end
+        end
+
+        expect { Config.load_files("#{fixture_path}/validation/config.yml") }.
+          to_not raise_error
+      end
     end
   end
 end