From 59af167d0a5df032fbaaa5c499bc8182abf4ba32 Mon Sep 17 00:00:00 2001
From: Mkou <marieke.gueye@gmail.com>
Date: Fri, 22 Apr 2016 14:53:09 -0700
Subject: [PATCH] Store `message_key` on `Grape::Exceptions::Validation`.

Store `message_key` on `Grape::Exceptions::Validation`.
---
 CHANGELOG.md                             |  3 +++
 lib/grape/exceptions/validation.rb       |  5 ++++-
 spec/grape/exceptions/validation_spec.rb | 10 ++++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c2a0cba425..004b7225a0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,9 @@
 
 * Your contribution here.
 
+#### Features
+* [#1366](https://github.com/ruby-grape/grape/pull/1366): Store `message_key` on `Grape::Exceptions::Validation` - [@mkou](https://github.com/mkou).
+
 0.16.2 (4/12/2016)
 ==================
 
diff --git a/lib/grape/exceptions/validation.rb b/lib/grape/exceptions/validation.rb
index 8c910875d1..46ba5b991d 100644
--- a/lib/grape/exceptions/validation.rb
+++ b/lib/grape/exceptions/validation.rb
@@ -9,7 +9,10 @@ class Validation < Grape::Exceptions::Base
       def initialize(args = {})
         fail 'Params are missing:' unless args.key? :params
         @params = args[:params]
-        args[:message] = translate_message(args[:message]) if args.key? :message
+        if args.key?(:message)
+          @message_key = args[:message] if args[:message].is_a?(Symbol)
+          args[:message] = translate_message(args[:message])
+        end
         super
       end
 
diff --git a/spec/grape/exceptions/validation_spec.rb b/spec/grape/exceptions/validation_spec.rb
index 1feae1e20c..ad338195ba 100644
--- a/spec/grape/exceptions/validation_spec.rb
+++ b/spec/grape/exceptions/validation_spec.rb
@@ -4,4 +4,14 @@
   it 'fails when params are missing' do
     expect { Grape::Exceptions::Validation.new(message: 'presence') }.to raise_error(RuntimeError, 'Params are missing:')
   end
+  context 'when message is a symbol' do
+    it 'stores message_key' do
+      expect(Grape::Exceptions::Validation.new(params: ['id'], message: :presence).message_key).to eq(:presence)
+    end
+  end
+  context 'when message is a String' do
+    it 'does not store the message_key' do
+      expect(Grape::Exceptions::Validation.new(params: ['id'], message: 'presence').message_key).to eq(nil)
+    end
+  end
 end