Answer:
The role of test oracle is to determine if a test has passed or failed. Oracle compares the outputs of the system under a test, for a given test-case input, and the output(s) that should have. A test oracle works on specifying constraints on the output(s) for a set of inputs. An oracle could be:
- a program which tells if the output is correct.
- documentation that specifies the correct output for inputs.
- a human that can tell whether it is correct an output.