Sorry, but no. The one way to find out is NOT to look at administrative and court rulings. For one thing, unemployment insurance is very private, individual cases and decisions are confidential, only when it goes into the civil court system does it become visible, therefore there are not a lot of court rulings and such out there to look at. And those are the rare and exceptional cases anyway. What you are describing is something dealt with in the regular system thousands of times a week.
So the cases you would find will very likely have nothing at all to do with your situation, will be from a variety of other states, which may be somewhat different from your own, and will not give you any definitive answers about your own individual situation, as we here cannot.
And you wouldn't have any use for them if you found them. You are not going to be going in and arguing for your approval for unemployment based on case law that you've found on the internet. Your approval decisions are going to be made by people within the state system who are already very familiar with the unemployment laws of your state and spend all their time working with it.
What you need to do, if you have already quit the job, is FILE A CLAIM in the state you are in, and let them work it out. It costs nothing, you have absolutely nothing to lose, and there is no down side to filing and having them give you a decision, two decisions actually if they deny the initial one.
However, I would strongly caution this OP. The answer is maybe, but not real likely, dependent on the individual circumstances. As everyone has pointed out, there must be a significant change in your job duties and pay rates, not just an adjustment. If you are already working in sales, and they have put you on commission rather than salary, but still selling the same product, this could very well be a common practice. (that deal where you sell vacuum cleaners comes to mind. After a few weeks or months on salary, when you have exhausted all your easy contacts and sold vacuum cleaners to all your friends and family who want to help you, they put you out on straight commission, and you are starved out, forced to quit. And no, as they know, you do not at this point get approved for unemployment insurance.)
And if you are still working there, and they have put you on commission, and you have continued to work, but are not making any money and are thinking about quitting, you need to know that quitting after having worked at the new job arrangement means that the job you are quitting is after you have already accepted the conditions of the new job and actually worked at it.
This means you knew it was going to be commission only, and did not quit before accepting it and trying it out. That lowers your chances of receiving approval for unemployment benefits significantly in any case.
If you are still working, try your best to keep the job till you find another one. You will be required to look for other work anyway, if you did happen to get approved for unemployment, and the chances are very slim that will happen.
If you've already quit, file a claim immediately. Even if they tell you no, you'll know for sure.