Make tests a bit more beautiful

activerecord/test/cases/hot_compatibility_test.rb

@@ -64,6 +64,9 @@ def self.name; 'HotCompatibility'; end
           record.reload
         end
 
+        assert get_prepared_statement_cache(@klass.connection).any?,
+          "expected prepared statement cache to have something in it"
+
         # add a new column
         ddl_connection.add_column :hot_compatibilities, :baz, :string
 
@@ -73,11 +76,7 @@ def self.name; 'HotCompatibility'; end
           end
         end
 
-        prepared_statement_cache = @klass.connection
-          .instance_variable_get(:@statements)
-          .instance_variable_get(:@cache)[Process.pid]
-
-        assert_empty prepared_statement_cache,
+        assert_empty get_prepared_statement_cache(@klass.connection),
           "expected prepared statement cache to be empty but it wasn't"
       end
     end
@@ -91,6 +90,9 @@ def self.name; 'HotCompatibility'; end
           record.reload
         end
 
+        assert get_prepared_statement_cache(@klass.connection).any?,
+          "expected prepared statement cache to have something in it"
+
         # add a new column
         ddl_connection.add_column :hot_compatibilities, :baz, :string
 
@@ -104,11 +106,7 @@ def self.name; 'HotCompatibility'; end
           end
         end
 
-        prepared_statement_cache = @klass.connection
-          .instance_variable_get(:@statements)
-          .instance_variable_get(:@cache)[Process.pid]
-
-        assert_empty prepared_statement_cache,
+        assert_empty get_prepared_statement_cache(@klass.connection),
           "expected prepared statement cache to be empty but it wasn't"
       end
     end
@@ -116,6 +114,11 @@ def self.name; 'HotCompatibility'; end
 
   private
 
+  def get_prepared_statement_cache(connection)
+    connection.instance_variable_get(:@statements)
+      .instance_variable_get(:@cache)[Process.pid]
+  end
+
   # Rails will automatically clear the prepared statements on the connection
   # that runs the migration, so we use two connections to simulate what would
   # actually happen on a production system; we'd have one connection running the