Very often couples going through a divorce still file a joint tax return. That is because as long as you are still legally married, you have the option to file jointly (you should discuss all tax ramifications with an accountant).
If you do file a joint tax return and a refund is issued, that refund is subject to equitable distribution just like any other marital asset. One party is not automatically entitled to keep the entire tax refund, even if they were the one that worked and the other spouse did not, as long as the taxed income was earned during the marriage.
I have seen many cases where one spouse takes the entire tax refund just as divorce proceedings are getting started. When that happens, an application can be made for the tax refund to be turned over and held in trust until the case has been resolved. If the money is no longer available, the other spouse usually receives a credit for a portion of the refund toward equitable distribution when it is settled.
Besides discussing your taxes with an accountant, it is important to speak with an attorney if you are about to go through a divorce and believe that you are owed an income tax refund.