Validate new before script CI configuration entry

lib/gitlab/ci/config/node/before_script.rb

@@ -8,6 +8,9 @@ module Gitlab
           end
 
           def validate!
+            unless validate_array_of_strings(@value)
+              @errors << 'before_script should be an array of strings'
+            end
           end
         end
       end

lib/gitlab/ci/config/node/entry.rb

@@ -3,10 +3,12 @@ module Gitlab
     class Config
       module Node
         class Entry
-          attr_reader :hash, :config, :parent, :nodes, :errors
+          include Config::ValidationHelpers
 
-          def initialize(hash, config, parent = nil)
-            @hash = hash
+          attr_reader :value, :config, :parent, :nodes, :errors
+
+          def initialize(value, config, parent = nil)
+            @value = value
             @config = config
             @parent = parent
             @nodes = {}
@@ -15,8 +17,8 @@ module Gitlab
 
           def process!
             keys.each_pair do |key, entry|
-              next unless hash.include?(key)
-              @nodes[key] = entry.new(hash[key], config, self)
+              next unless @value.include?(key)
+              @nodes[key] = entry.new(@value[key], config, self)
             end
 
             @nodes.values.each(&:process!)

spec/lib/gitlab/ci/config/node/before_script_spec.rb

 require 'spec_helper'
 
 describe Gitlab::Ci::Config::Node::BeforeScript do
-  let(:entry) { described_class.new(hash, config) }
+  let(:entry) { described_class.new(value, config) }
+  let(:config) { double('config') }
+
+  describe '#validate!' do
+    before { entry.validate! }
+
+    context 'when entry value is correct' do
+      let(:value) { ['ls', 'pwd'] }
+
+      it 'does not append errors' do
+        expect(entry.errors).to be_empty
+      end
+    end
+
+    context 'when entry value is not correct' do
+      let(:value) { 'ls' }
+
+      it 'saves errors' do
+        expect(entry.errors)
+          .to include /should be an array of strings/
+      end
+    end
+  end
 end