Fix tests for prepared_statements: false and queries hitting `#select_all`

- The query needs to be executed for hitting `select_all` so made sure
  that query gets executed.
- Also instead of changing instance variable, just add new
  configuration for prepared_statements: false and use it for this
  test.
- This way we don't have to touch the internals of AR code and still
  disable prepared statements config for this test.

1 files changed, 4 insertions, 4 deletions

diff --git a/activerecord/test/cases/adapters/postgresql/prepared_statements_test.rb b/activerecord/test/cases/adapters/postgresql/prepared_statements_test.rb
index 181c1a097c..1214b28366 100644
--- a/activerecord/test/cases/adapters/postgresql/prepared_statements_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/prepared_statements_test.rb
@@ -6,17 +6,17 @@ class PreparedStatementsTest < ActiveRecord::PostgreSQLTestCase
   fixtures :developers
 
   def setup
-    @default_prepared_statements = ActiveRecord::Base.connection.instance_variable_get("@prepared_statements")
-    ActiveRecord::Base.connection.instance_variable_set("@prepared_statements", false)
+    @conn = ActiveRecord::Base.establish_connection :arunit_with_prepared_statements
   end
 
   def teardown
-    ActiveRecord::Base.connection.instance_variable_set("@prepared_statements", @default_prepared_statements)
+    @conn.release_connection
+    ActiveRecord::Base.establish_connection :arunit
   end
 
   def test_nothing_raised_with_falsy_prepared_statements
     assert_nothing_raised do
-      Developer.where(id: 1)
+      Developer.where(id: 1).to_a
     end
   end
 end