Add supports_common_table_expressions? for CTE testing

Author: kamipo

activerecord/lib/active_record/connection_adapters/abstract_adapter.rb

@@ -416,6 +416,10 @@ def supports_optimizer_hints?
         false
       end
 
+      def supports_common_table_expressions?
+        false
+      end
+
       def supports_lazy_transactions?
         false
       end

activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb

@@ -110,6 +110,14 @@ def supports_optimizer_hints?
         !mariadb? && database_version >= "5.7.7"
       end
 
+      def supports_common_table_expressions?
+        if mariadb?
+          database_version >= "10.2.1"
+        else
+          database_version >= "8.0.1"
+        end
+      end
+
       def supports_advisory_locks?
         true
       end

activerecord/lib/active_record/connection_adapters/postgresql/database_statements.rb

@@ -67,7 +67,9 @@ def query(sql, name = nil) #:nodoc:
           end
         end
 
-        READ_QUERY = ActiveRecord::ConnectionAdapters::AbstractAdapter.build_read_query_regexp(:begin, :commit, :explain, :select, :set, :show, :release, :savepoint, :rollback, :with) # :nodoc:
+        READ_QUERY = ActiveRecord::ConnectionAdapters::AbstractAdapter.build_read_query_regexp(
+          :begin, :commit, :explain, :select, :set, :show, :release, :savepoint, :rollback, :with
+        ) # :nodoc:
         private_constant :READ_QUERY
 
         def write_query?(sql) # :nodoc:

activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb

@@ -361,6 +361,10 @@ def supports_optimizer_hints?
         @has_pg_hint_plan
       end
 
+      def supports_common_table_expressions?
+        true
+      end
+
       def supports_lazy_transactions?
         true
       end

activerecord/lib/active_record/connection_adapters/sqlite3/database_statements.rb

@@ -4,7 +4,9 @@ module ActiveRecord
   module ConnectionAdapters
     module SQLite3
       module DatabaseStatements
-        READ_QUERY = ActiveRecord::ConnectionAdapters::AbstractAdapter.build_read_query_regexp(:begin, :commit, :explain, :select, :pragma, :release, :savepoint, :rollback, :with) # :nodoc:
+        READ_QUERY = ActiveRecord::ConnectionAdapters::AbstractAdapter.build_read_query_regexp(
+          :begin, :commit, :explain, :select, :pragma, :release, :savepoint, :rollback, :with
+        ) # :nodoc:
         private_constant :READ_QUERY
 
         def write_query?(sql) # :nodoc:

activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb

@@ -144,6 +144,10 @@ def supports_json?
         true
       end
 
+      def supports_common_table_expressions?
+        database_version >= "3.8.3"
+      end
+
       def supports_insert_on_conflict?
         database_version >= "3.24.0"
       end

activerecord/test/cases/adapter_test.rb

@@ -223,6 +223,20 @@ def test_doesnt_error_when_a_select_query_is_called_while_preventing_writes
       end
     end
 
+    if ActiveRecord::Base.connection.supports_common_table_expressions?
+      def test_doesnt_error_when_a_read_query_with_a_cte_is_called_while_preventing_writes
+        @connection.insert("INSERT INTO subscribers(nick) VALUES ('138853948594')")
+
+        @connection_handler.while_preventing_writes do
+          result = @connection.select_all(<<~SQL)
+            WITH matching_subscribers AS (SELECT subscribers.* FROM subscribers WHERE nick = '138853948594')
+            SELECT * FROM matching_subscribers
+          SQL
+          assert_equal 1, result.length
+        end
+      end
+    end
+
     def test_uniqueness_violations_are_translated_to_specific_exception
       @connection.execute "INSERT INTO subscribers(nick) VALUES('me')"
       error = assert_raises(ActiveRecord::RecordNotUnique) do

activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb

@@ -232,15 +232,6 @@ def test_doesnt_error_when_a_read_query_with_leading_chars_is_called_while_preve
     end
   end
 
-  def test_doesnt_error_when_a_read_query_with_a_cte_is_called_while_preventing_writes
-    @conn.execute("INSERT INTO `engines` (`car_id`) VALUES ('138853948594')")
-
-    @connection_handler.while_preventing_writes do
-      sql = "WITH matching_cars AS (SELECT `engines`.* FROM `engines` WHERE `engines`.`car_id` = '138853948594') SELECT * FROM matching_cars"
-      assert_equal 1, @conn.execute(sql).entries.count
-    end
-  end
-
   def test_statement_timeout_error_codes
     raw_conn = @conn.raw_connection
     assert_raises(ActiveRecord::StatementTimeout) do

activerecord/test/cases/adapters/postgresql/postgresql_adapter_test.rb

@@ -457,17 +457,6 @@ def test_doesnt_error_when_a_read_query_with_leading_chars_is_called_while_preve
         end
       end
 
-      def test_doesnt_error_when_a_read_query_with_a_cte_is_called_while_preventing_writes
-        with_example_table do
-          @connection.execute("INSERT INTO ex (data) VALUES ('138853948594')")
-
-          @connection_handler.while_preventing_writes do
-            sql = "WITH matching_ex_values AS (SELECT * FROM ex WHERE data = '138853948594') SELECT * FROM matching_ex_values"
-            assert_equal 1, @connection.execute(sql).entries.count
-          end
-        end
-      end
-
       private
 
         def with_example_table(definition = "id serial primary key, number integer, data character varying(255)", &block)

activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb

@@ -653,17 +653,6 @@ def test_doesnt_error_when_a_read_query_with_leading_chars_is_called_while_preve
         end
       end
 
-      def test_doesnt_error_when_a_read_query_with_a_cte_is_called_while_preventing_writes
-        with_example_table "id int, data string" do
-          @conn.execute("INSERT INTO ex (data) VALUES ('138853948594')")
-
-          @connection_handler.while_preventing_writes do
-            sql = "WITH matching_ex_values AS (SELECT * FROM ex WHERE data = '138853948594') SELECT * FROM matching_ex_values"
-            assert_equal 1, @conn.execute(sql).entries.count
-          end
-        end
-      end
-
       private
 
         def assert_logged(logs)