Port changes for CODEOWNERS to CE

This ports the changes for the CODEOWNERS feature to CE:
- It adds the CODEOWNERS file.
- It adds the mention of the `with-codeowners` branch in TestEnv

1 files changed, 34 insertions, 11 deletions

diff --git a/app/models/concerns/case_sensitivity.rb b/app/models/concerns/case_sensitivity.rb
index 6e80365ee5b..c93b6589ee7 100644
--- a/app/models/concerns/case_sensitivity.rb
+++ b/app/models/concerns/case_sensitivity.rb
@@ -9,23 +9,46 @@ module CaseSensitivity
     #
     # Unlike other ActiveRecord methods this method only operates on a Hash.
     def iwhere(params)
-      criteria   = self
-      cast_lower = Gitlab::Database.postgresql?
+      criteria = self
 
       params.each do |key, value|
-        column = ActiveRecord::Base.connection.quote_table_name(key)
+        criteria = case value
+                   when Array
+                     criteria.where(value_in(key, value))
+                   else
+                     criteria.where(value_equal(key, value))
+                   end
+      end
+
+      criteria
+    end
 
-        condition =
-          if cast_lower
-            "LOWER(#{column}) = LOWER(:value)"
-          else
-            "#{column} = :value"
-          end
+    private
+
+    def value_equal(column, value)
+      lower_value = lower_value(value)
+
+      lower_column(arel_table[column]).eq(lower_value).to_sql
+    end
 
-        criteria = criteria.where(condition, value: value)
+    def value_in(column, values)
+      lower_values = values.map do |value|
+        lower_value(value)
       end
 
-      criteria
+      lower_column(arel_table[column]).in(lower_values).to_sql
+    end
+
+    def lower_value(value)
+      return value if Gitlab::Database.mysql?
+
+      Arel::Nodes::NamedFunction.new('LOWER', [Arel::Nodes.build_quoted(value)])
+    end
+
+    def lower_column(column)
+      return column if Gitlab::Database.mysql?
+
+      column.lower
     end
   end
 end