Metamorphic Testing: Using the Properties of Sut

when testing a program, correctly executed test cases are seldom explored further, even though they may carry useful information. Metamorphic testing proposes to generate follow-up test cases to check important properties of the target function. It does not need a human oracle for output prediction and comparison. An “oracle” in software testing is a procedure by which testers can decide whether the output of the program under testing is correct. In some situations, however, the oracle is not available or too difficult to apply. This is known as the “oracle problem”. The manual prediction and verification of program output greatly decreases the efficiency and increases the cost of testing. A metamorphic testing method has been proposed to test programs without the involvement of an oracle. It employs properties of the target function, known as metamorphic relations, to generate follow-up test cases and verify the outputs automatically.