Clear query cache when truncate table(s)

activerecord/lib/active_record/connection_adapters/abstract/query_cache.rb

@@ -7,7 +7,8 @@ module ConnectionAdapters # :nodoc:
     module QueryCache
       class << self
         def included(base) #:nodoc:
-          dirties_query_cache base, :insert, :update, :delete, :rollback_to_savepoint, :rollback_db_transaction
+          dirties_query_cache base, :insert, :update, :delete, :truncate, :truncate_tables,
+            :rollback_to_savepoint, :rollback_db_transaction
 
           base.set_callback :checkout, :after, :configure_query_cache!
           base.set_callback :checkin, :after, :disable_query_cache!

activerecord/test/cases/adapter_test.rb

@@ -485,23 +485,51 @@ def setup
     end
 
     def test_truncate
-      assert_operator @connection.query_value("SELECT COUNT(*) FROM posts"), :>, 0
+      assert_operator Post.count, :>, 0
 
       @connection.truncate("posts")
 
-      assert_equal 0, @connection.query_value("SELECT COUNT(*) FROM posts")
+      assert_equal 0, Post.count
+    end
+
+    def test_truncate_with_query_cache
+      @connection.enable_query_cache!
+
+      assert_operator Post.count, :>, 0
+
+      @connection.truncate("posts")
+
+      assert_equal 0, Post.count
+    ensure
+      @connection.disable_query_cache!
     end
 
     def test_truncate_tables
-      assert_operator @connection.query_value("SELECT COUNT(*) FROM posts"), :>, 0
-      assert_operator @connection.query_value("SELECT COUNT(*) FROM authors"), :>, 0
-      assert_operator @connection.query_value("SELECT COUNT(*) FROM author_addresses"), :>, 0
+      assert_operator Post.count, :>, 0
+      assert_operator Author.count, :>, 0
+      assert_operator AuthorAddress.count, :>, 0
 
       @connection.truncate_tables("author_addresses", "authors", "posts")
 
-      assert_equal 0, @connection.query_value("SELECT COUNT(*) FROM posts")
-      assert_equal 0, @connection.query_value("SELECT COUNT(*) FROM authors")
-      assert_equal 0, @connection.query_value("SELECT COUNT(*) FROM author_addresses")
+      assert_equal 0, Post.count
+      assert_equal 0, Author.count
+      assert_equal 0, AuthorAddress.count
+    end
+
+    def test_truncate_tables_with_query_cache
+      @connection.enable_query_cache!
+
+      assert_operator Post.count, :>, 0
+      assert_operator Author.count, :>, 0
+      assert_operator AuthorAddress.count, :>, 0
+
+      @connection.truncate_tables("author_addresses", "authors", "posts")
+
+      assert_equal 0, Post.count
+      assert_equal 0, Author.count
+      assert_equal 0, AuthorAddress.count
+    ensure
+      @connection.disable_query_cache!
     end
 
     # test resetting sequences in odd tables in PostgreSQL