It really is a testament to NASA that they managed a moon landing without this level of testing. I wonder how much further along we'd be if there hadn't been a run of visionless administrations.
NASA definitely did this exact same testing for Apollo, I'm not sure why you assumed they didn't.
[1] https://en.wikipedia.org/wiki/Commercial_Resupply_Services
[2] https://en.wikipedia.org/wiki/Commercial_Crew_Development