How about this?
The answer depends on what is 'testing'?
The minimum requirement for starting testing would be a Functional Requirement sSpecifications (FRS) aka Business Requirements Document. I would start testing by reviewing this document.
If testing means functional testing then I would need
1. BRD/FRS as mentioned earlier
2. All written test cases for the feature(s) decided to be tested
3. A build form development that
a. compiles installs and runs without major errors (in other words passes sanity/smoke testing)
b. contains the functionality being tested.