1 files changed, 27 insertions, 0 deletions
diff --git a/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb b/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb
index e1f7a0b7c5..cfc1823773 100644
--- a/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/mysql2_adapter_test.rb
@@ -20,6 +20,18 @@ class Mysql2AdapterTest < ActiveRecord::Mysql2TestCase
     end
   end
 
+  def test_database_exists_returns_false_if_database_does_not_exist
+    config = ActiveRecord::Base.configurations["arunit"].merge(database: "inexistent_activerecord_unittest")
+    assert_not ActiveRecord::ConnectionAdapters::Mysql2Adapter.database_exists?(config),
+      "expected database to not exist"
+  end
+
+  def test_database_exists_returns_true_when_the_database_exists
+    config = ActiveRecord::Base.configurations["arunit"]
+    assert ActiveRecord::ConnectionAdapters::Mysql2Adapter.database_exists?(config),
+     "expected database #{config[:database]} to exist"
+  end
+
   def test_columns_for_distinct_zero_orders
     assert_equal "posts.id",
       @conn.columns_for_distinct("posts.id", [])
@@ -213,6 +225,21 @@ class Mysql2AdapterTest < ActiveRecord::Mysql2TestCase
     end
   end
 
+  def test_read_timeout_exception
+    ActiveRecord::Base.establish_connection(
+      ActiveRecord::Base.configurations[:arunit].merge("read_timeout" => 1)
+    )
+
+    error = assert_raises(ActiveRecord::AdapterTimeout) do
+      ActiveRecord::Base.connection.execute("SELECT SLEEP(2)")
+    end
+    assert_kind_of ActiveRecord::QueryAborted, error
+
+    assert_equal Mysql2::Error::TimeoutError, error.cause.class
+  ensure
+    ActiveRecord::Base.establish_connection :arunit
+  end
+
   private
     def with_example_table(definition = "id int auto_increment primary key, number int, data varchar(255)", &block)
       super(@conn, "ex", definition, &block)