From 6296617c159d5cee0ba1c76f4ea983e3b5e26b6b Mon Sep 17 00:00:00 2001
From: James Le Cuirot <james.le-cuirot@yakara.com>
Date: Fri, 7 Mar 2014 13:15:33 +0000
Subject: [PATCH] Add Regexp and NotRegexp nodes for PostgreSQL

---
 lib/arel/nodes/binary.rb         |  2 ++
 lib/arel/visitors/depth_first.rb |  2 ++
 lib/arel/visitors/postgresql.rb  |  8 ++++++++
 lib/arel/visitors/to_sql.rb      |  8 ++++++++
 test/visitors/test_postgres.rb   | 34 ++++++++++++++++++++++++++++++++
 test/visitors/test_to_sql.rb     | 20 +++++++++++++++++++
 6 files changed, 74 insertions(+)

diff --git a/lib/arel/nodes/binary.rb b/lib/arel/nodes/binary.rb
index 0e7e281b4b..939684957f 100644
--- a/lib/arel/nodes/binary.rb
+++ b/lib/arel/nodes/binary.rb
@@ -40,7 +40,9 @@ module Arel
       Matches
       NotEqual
       NotIn
+      NotRegexp
       Or
+      Regexp
       Union
       UnionAll
       Intersect
diff --git a/lib/arel/visitors/depth_first.rb b/lib/arel/visitors/depth_first.rb
index 7043e5d527..4d2ecfa5e1 100644
--- a/lib/arel/visitors/depth_first.rb
+++ b/lib/arel/visitors/depth_first.rb
@@ -79,8 +79,10 @@ module Arel
       alias :visit_Arel_Nodes_Matches            :binary
       alias :visit_Arel_Nodes_NotEqual           :binary
       alias :visit_Arel_Nodes_NotIn              :binary
+      alias :visit_Arel_Nodes_NotRegexp          :binary
       alias :visit_Arel_Nodes_Or                 :binary
       alias :visit_Arel_Nodes_OuterJoin          :binary
+      alias :visit_Arel_Nodes_Regexp             :binary
       alias :visit_Arel_Nodes_RightOuterJoin     :binary
       alias :visit_Arel_Nodes_TableAlias         :binary
       alias :visit_Arel_Nodes_Values             :binary
diff --git a/lib/arel/visitors/postgresql.rb b/lib/arel/visitors/postgresql.rb
index 812710181c..49f7482e7d 100644
--- a/lib/arel/visitors/postgresql.rb
+++ b/lib/arel/visitors/postgresql.rb
@@ -11,6 +11,14 @@ module Arel
         "#{visit o.left} NOT ILIKE #{visit o.right}"
       end
 
+      def visit_Arel_Nodes_Regexp o
+        "#{visit o.left} ~ #{visit o.right}"
+      end
+
+      def visit_Arel_Nodes_NotRegexp o
+        "#{visit o.left} !~ #{visit o.right}"
+      end
+
       def visit_Arel_Nodes_DistinctOn o
         "DISTINCT ON ( #{visit o.expr} )"
       end
diff --git a/lib/arel/visitors/to_sql.rb b/lib/arel/visitors/to_sql.rb
index 84a88e1899..c1c192fa1a 100644
--- a/lib/arel/visitors/to_sql.rb
+++ b/lib/arel/visitors/to_sql.rb
@@ -435,6 +435,14 @@ module Arel
         "#{visit o.left} NOT LIKE #{visit o.right}"
       end
 
+      def visit_Arel_Nodes_Regexp o
+        raise NotImplementedError, '~ not implemented for this db'
+      end
+
+      def visit_Arel_Nodes_NotRegexp o
+        raise NotImplementedError, '!~ not implemented for this db'
+      end
+
       def visit_Arel_Nodes_JoinSource o
         [
           (visit(o.left) if o.left),
diff --git a/test/visitors/test_postgres.rb b/test/visitors/test_postgres.rb
index 4287baaf14..995e9bf515 100644
--- a/test/visitors/test_postgres.rb
+++ b/test/visitors/test_postgres.rb
@@ -79,6 +79,40 @@ module Arel
           }
         end
       end
+
+      describe "Nodes::Regexp" do
+        it "should know how to visit" do
+          node = Arel::Nodes::Regexp.new(@table[:name], Nodes.build_quoted('foo%'))
+          @visitor.accept(node).must_be_like %{
+            "users"."name" ~ 'foo%'
+          }
+        end
+
+        it 'can handle subqueries' do
+          subquery = @table.project(:id).where(Arel::Nodes::Regexp.new(@table[:name], Nodes.build_quoted('foo%')))
+          node = @attr.in subquery
+          @visitor.accept(node).must_be_like %{
+            "users"."id" IN (SELECT id FROM "users" WHERE "users"."name" ~ 'foo%')
+          }
+        end
+      end
+
+      describe "Nodes::NotRegexp" do
+        it "should know how to visit" do
+          node = Arel::Nodes::NotRegexp.new(@table[:name], Nodes.build_quoted('foo%'))
+          @visitor.accept(node).must_be_like %{
+            "users"."name" !~ 'foo%'
+          }
+        end
+
+        it 'can handle subqueries' do
+          subquery = @table.project(:id).where(Arel::Nodes::NotRegexp.new(@table[:name], Nodes.build_quoted('foo%')))
+          node = @attr.in subquery
+          @visitor.accept(node).must_be_like %{
+            "users"."id" IN (SELECT id FROM "users" WHERE "users"."name" !~ 'foo%')
+          }
+        end
+      end
     end
   end
 end
diff --git a/test/visitors/test_to_sql.rb b/test/visitors/test_to_sql.rb
index b142ecd695..644951d71c 100644
--- a/test/visitors/test_to_sql.rb
+++ b/test/visitors/test_to_sql.rb
@@ -526,6 +526,26 @@ module Arel
           end
         end
       end
+
+      describe 'Nodes::Regexp' do
+        it 'raises not implemented error' do
+          node = Arel::Nodes::Regexp.new(@table[:name], Nodes.build_quoted('foo%'))
+
+          assert_raises(NotImplementedError) do
+            @visitor.accept(node)
+          end
+        end
+      end
+
+      describe 'Nodes::NotRegexp' do
+        it 'raises not implemented error' do
+          node = Arel::Nodes::NotRegexp.new(@table[:name], Nodes.build_quoted('foo%'))
+
+          assert_raises(NotImplementedError) do
+            @visitor.accept(node)
+          end
+        end
+      end
     end
   end
 end