Merge "Avoid accidentally sharing preparers slice across factories"

}

func (f *fixtureFactory) Extend(preparers ...FixturePreparer) FixtureFactory {

	all := append(f.preparers, dedupAndFlattenPreparers(f.preparers, preparers)...)

	// Create a new slice to avoid accidentally sharing the preparers slice from this factory with

	// the extending factories.

	var all []*simpleFixturePreparer

	all = append(all, f.preparers...)

	all = append(all, dedupAndFlattenPreparers(f.preparers, preparers)...)

	// Copy the existing factory.

	extendedFactory := &fixtureFactory{}

	*extendedFactory = *f