fixtures: added post processors to loaders

[j4k4]

Major change of this release is the additions of post processors to the fixture package. These allow additional handling after loading the fixture data, e.g. populating internal caches. For this change, the signatures of adding fixtures has changed slightly:

func main() {
	application.RunHttpDefaultServer(
		api.DefineRouter,
		application.WithFixtureSetFactory("default", service.FixtureSetsFactory, service.PostProcessor),
	)
}

or if you want to add multiple groups with the same post processor:

func main() {
	application.RunHttpDefaultServer(
		api.DefineRouter,
		application.WithFixtureSetFactories(map[string]fixtures.FixtureSetsFactory{
			"group1": service.FixtureSetsFactory1,
			"group2": service.FixtureSetsFactory2,
		}, service.PostProcessor),
	)
}

The options for creating test suites have been adjusted accordingly:

func (s *TestSuite) SetupSuite() []suite.Option {
	return []suite.Option{
		suite.WithLogLevel(log.LevelWarn),
		suite.WithConfigFile("./config.test.yml"),
		suite.WithFixtureSetFactory(service.FixtureSetsFactory, service.PostProcessors...),
	}
}

and

func (s *TestSuite) SetupSuite() []suite.Option {
	return []suite.Option{
		suite.WithLogLevel("warn"),
		suite.WithConfigFile("../config.test.yml"),
		suite.WithFixtureSetFactories([]fixtures.FixtureSetsFactory{
			common.FixtureSetsFactory,
			service.FixtureSetsFactory,
		}, service.PostProcessor),
	}
}

Post processors have to implement a simple interface:

type PostProcessor interface {
	Process(ctx context.Context) error
}