1 files changed, 109 insertions, 0 deletions
diff --git a/activerecord/test/cases/arel/visitors/mysql_test.rb b/activerecord/test/cases/arel/visitors/mysql_test.rb
new file mode 100644
index 0000000000..5f37587957
--- /dev/null
+++ b/activerecord/test/cases/arel/visitors/mysql_test.rb
@@ -0,0 +1,109 @@
+# frozen_string_literal: true
+
+require_relative "../helper"
+
+module Arel
+  module Visitors
+    class MysqlTest < Arel::Spec
+      before do
+        @visitor = MySQL.new Table.engine.connection
+      end
+
+      def compile(node)
+        @visitor.accept(node, Collectors::SQLString.new).value
+      end
+
+      ###
+      # :'(
+      # http://dev.mysql.com/doc/refman/5.0/en/select.html#id3482214
+      it "defaults limit to 18446744073709551615" do
+        stmt = Nodes::SelectStatement.new
+        stmt.offset = Nodes::Offset.new(1)
+        sql = compile(stmt)
+        sql.must_be_like "SELECT FROM DUAL LIMIT 18446744073709551615 OFFSET 1"
+      end
+
+      it "should escape LIMIT" do
+        sc = Arel::Nodes::UpdateStatement.new
+        sc.relation = Table.new(:users)
+        sc.limit = Nodes::Limit.new(Nodes.build_quoted("omg"))
+        assert_equal("UPDATE \"users\" LIMIT 'omg'", compile(sc))
+      end
+
+      it "uses DUAL for empty from" do
+        stmt = Nodes::SelectStatement.new
+        sql = compile(stmt)
+        sql.must_be_like "SELECT FROM DUAL"
+      end
+
+      describe "locking" do
+        it "defaults to FOR UPDATE when locking" do
+          node = Nodes::Lock.new(Arel.sql("FOR UPDATE"))
+          compile(node).must_be_like "FOR UPDATE"
+        end
+
+        it "allows a custom string to be used as a lock" do
+          node = Nodes::Lock.new(Arel.sql("LOCK IN SHARE MODE"))
+          compile(node).must_be_like "LOCK IN SHARE MODE"
+        end
+      end
+
+      describe "concat" do
+        it "concats columns" do
+          @table = Table.new(:users)
+          query = @table[:name].concat(@table[:name])
+          compile(query).must_be_like %{
+            CONCAT("users"."name", "users"."name")
+          }
+        end
+
+        it "concats a string" do
+          @table = Table.new(:users)
+          query = @table[:name].concat(Nodes.build_quoted("abc"))
+          compile(query).must_be_like %{
+            CONCAT("users"."name", 'abc')
+          }
+        end
+      end
+
+      describe "Nodes::IsNotDistinctFrom" do
+        it "should construct a valid generic SQL statement" do
+          test = Table.new(:users)[:name].is_not_distinct_from "Aaron Patterson"
+          compile(test).must_be_like %{
+            "users"."name" <=> 'Aaron Patterson'
+          }
+        end
+
+        it "should handle column names on both sides" do
+          test = Table.new(:users)[:first_name].is_not_distinct_from Table.new(:users)[:last_name]
+          compile(test).must_be_like %{
+            "users"."first_name" <=> "users"."last_name"
+          }
+        end
+
+        it "should handle nil" do
+          @table = Table.new(:users)
+          val = Nodes.build_quoted(nil, @table[:active])
+          sql = compile Nodes::IsNotDistinctFrom.new(@table[:name], val)
+          sql.must_be_like %{ "users"."name" <=> NULL }
+        end
+      end
+
+      describe "Nodes::IsDistinctFrom" do
+        it "should handle column names on both sides" do
+          test = Table.new(:users)[:first_name].is_distinct_from Table.new(:users)[:last_name]
+          compile(test).must_be_like %{
+            NOT "users"."first_name" <=> "users"."last_name"
+          }
+        end
+
+        it "should handle nil" do
+          @table = Table.new(:users)
+          val = Nodes.build_quoted(nil, @table[:active])
+          sql = compile Nodes::IsDistinctFrom.new(@table[:name], val)
+          sql.must_be_like %{ NOT "users"."name" <=> NULL }
+        end
+      end
+    end
+  end
+end