Add same_as validator

CHANGELOG.md

@@ -3,6 +3,7 @@
 #### Features
 
 * Your contribution here.
+* [#1850](https://github.com/ruby-grape/grape/pull/1850): Adds `same_as` validator - [@glaucocustodio](https://github.com/glaucocustodio).
 * [#1833](https://github.com/ruby-grape/grape/pull/1833): Allows to set the `ParamBuilder` globally - [@myxoh](https://github.com/myxoh).
 * [#1844](https://github.com/ruby-grape/grape/pull/1844): Fix: enforce `:tempfile` to be a `Tempfile` object in `File` validator - [@Nyangawa](https://github.com/Nyangawa).
 

README.md

@@ -50,6 +50,7 @@
     - [allow_blank](#allow_blank)
     - [values](#values)
     - [except_values](#except_values)
+    - [same_as](#same_as)
     - [regexp](#regexp)
     - [mutually_exclusive](#mutually_exclusive)
     - [exactly_one_of](#exactly_one_of)
@@ -62,6 +63,7 @@
   - [I18n](#i18n)
   - [Custom Validation messages](#custom-validation-messages)
     - [presence, allow_blank, values, regexp](#presence-allow_blank-values-regexp)
+    - [same_as](#same_as-1)
     - [all_or_none_of](#all_or_none_of-1)
     - [mutually_exclusive](#mutually_exclusive-1)
     - [exactly_one_of](#exactly_one_of-1)
@@ -1351,6 +1353,17 @@ params do
 end
 ```
 
+#### `same_as`
+
+A `same_as` option can be given to ensure that values of parameters match.
+
+```ruby
+params do
+  requires :password
+  requires :password_confirmation, same_as: :password
+end
+```
+
 #### `regexp`
 
 Parameters can be restricted to match a specific regular expression with the `:regexp` option. If the value
@@ -1663,6 +1676,15 @@ params do
 end
 ```
 
+#### `same_as`
+
+```ruby
+params do
+  requires :password
+  requires :password_confirmation, same_as: { value: :password, message: 'not match' }
+end
+```
+
 #### `all_or_none_of`
 
 ```ruby

lib/grape.rb

@@ -207,6 +207,7 @@ module ServeFile
 require 'grape/validations/validators/mutual_exclusion'
 require 'grape/validations/validators/presence'
 require 'grape/validations/validators/regexp'
+require 'grape/validations/validators/same_as'
 require 'grape/validations/validators/values'
 require 'grape/validations/validators/except_values'
 require 'grape/validations/params_scope'

lib/grape/locale/en.yml

@@ -9,6 +9,7 @@ en:
         blank: 'is empty'
         values: 'does not have a valid value'
         except_values: 'has a value not allowed'
+        same_as: 'is not the same as %{parameter}'
         missing_vendor_option:
           problem: 'missing :vendor option.'
           summary: 'when version using header, you must specify :vendor option. '

lib/grape/validations/validators/same_as.rb

@@ -0,0 +1,23 @@
+module Grape
+  module Validations
+    class SameAsValidator < Base
+      def validate_param!(attr_name, params)
+        confirmation = options_key?(:value) ? @option[:value] : @option
+        return if params[attr_name] == params[confirmation]
+        raise Grape::Exceptions::Validation,
+              params: [@scope.full_name(attr_name)],
+              message: build_message
+      end
+
+      private
+
+      def build_message
+        if options_key?(:message)
+          @option[:message]
+        else
+          format I18n.t(:same_as, scope: 'grape.errors.messages'), parameter: @option
+        end
+      end
+    end
+  end
+end

spec/grape/validations/validators/same_as_spec.rb

@@ -0,0 +1,63 @@
+require 'spec_helper'
+
+describe Grape::Validations::SameAsValidator do
+  module ValidationsSpec
+    module SameAsValidatorSpec
+      class API < Grape::API
+        params do
+          requires :password
+          requires :password_confirmation, same_as: :password
+        end
+        post do
+        end
+
+        params do
+          requires :password
+          requires :password_confirmation, same_as: { value: :password, message: 'not match' }
+        end
+        post '/custom-message' do
+        end
+      end
+    end
+  end
+
+  def app
+    ValidationsSpec::SameAsValidatorSpec::API
+  end
+
+  describe '/' do
+    context 'is the same' do
+      it do
+        post '/', password: '987654', password_confirmation: '987654'
+        expect(last_response.status).to eq(201)
+        expect(last_response.body).to eq('')
+      end
+    end
+
+    context 'is not the same' do
+      it do
+        post '/', password: '123456', password_confirmation: 'whatever'
+        expect(last_response.status).to eq(400)
+        expect(last_response.body).to eq('password_confirmation is not the same as password')
+      end
+    end
+  end
+
+  describe '/custom-message' do
+    context 'is the same' do
+      it do
+        post '/custom-message', password: '987654', password_confirmation: '987654'
+        expect(last_response.status).to eq(201)
+        expect(last_response.body).to eq('')
+      end
+    end
+
+    context 'is not the same' do
+      it do
+        post '/custom-message', password: '123456', password_confirmation: 'whatever'
+        expect(last_response.status).to eq(400)
+        expect(last_response.body).to eq('password_confirmation not match')
+      end
+    end
+  end
+end

spec/spec_helper.rb

@@ -20,6 +20,7 @@
   config.include Rack::Test::Methods
   config.include Spec::Support::Helpers
   config.raise_errors_for_deprecations!
+  config.filter_run_when_matching :focus
 
   config.before(:each) { Grape::Util::InheritableSetting.reset_global! }
 end