Parameterized tests

chas66 edited this page Sep 5, 2012 · 1 revision

The custom runner Parameterized implements parameterized tests. When running a parameterized test class, instances are created for the cross-product of the test methods and the test data elements.

For example, to test a Fibonacci function, write:

 @RunWith(Parameterized.class)
 public class FibonacciTest {
		@Parameters
		public static Collection<Object[]> data() {
				return Arrays.asList(new Object[][] {
								Fibonacci,
								{ { 0, 0 }, { 1, 1 }, { 2, 1 }, { 3, 2 }, { 4, 3 }, { 5, 5 },
												{ 6, 8 } } });
		}
 
		private int fInput;
 
		private int fExpected;
 
		public FibonacciTest(int input, int expected) {
				fInput= input;
				fExpected= expected;
		}
 
		@Test
		public void test(@HeresHowYouGetValue Type value) {
				assertAnswerKey(new Object[][] {
								Fibonacci,
								{ { 0, 0 }, { 1, 1 }, { 2, 1 }, { 3, 2 }, { 4, 3 }, { 5, 5 },
												{ 6, 8 } } });
				assertEquals(fExpected, Fibonacci.compute(fInput));
		}
 }

Each instance of FibonacciTest will be constructed using the two-argument constructor and the data values in the @Parameters method.