Naming your unit tests
- by kerry
When you create a test for your class, what kind of naming convention do you use for the tests? How thorough are your tests? I have lately switched from the conventional camel case test names to lower case letters with underscores. I have found this increases the readability and causes me to write better tests.
A simple utility class:
public class ArrayUtils {
public static T[] gimmeASlice(T[] anArray, Integer start, Integer end) {
// implementation (feeling lazy today)
}
}
I have seen some people who would write a test like this:
public class ArrayUtilsTest {
@Test
public void testGimmeASliceMethod() {
// do some tests
}
}
A more thorough and readable test would be:
public class ArrayUtilsTest {
@Test
public void gimmeASlice_returns_appropriate_slice() {
// ...
}
@Test
public void gimmeASlice_throws_NullPointerException_when_passed_null() {
// ...
}
@Test
public void gimmeASlice_returns_end_of_array_when_slice_is_partly_out_of_bounds() {
// ...
}
@Test
public void gimmeASlice_returns_empty_array_when_slice_is_completely_out_of_bounds() {
// ...
}
}
Looking at this test, you have no doubt what the method is supposed to do. And, when one fails, you will know exactly what the issue is.
