JUnit Test With More than One Accepted Answer

Question

Is it possible to have multiple accepted answers in a JUnit test? So for example:

   Main rock = new Main();
   Assert.assertEquals("y", boxes("23"));

So for this test I want to be able to accept the result string "y" or "n" as an acceptable answer, is that possible?

Answer 1

使用Hamcrest CoreMatcher（包含在JUnit 4.4和更高版本中）和assertThat（）：

Assert.assertThat(boxes("23"), anyOf(is("y"), is("n"));

Answer 2

You can do it, but not with assertEquals() . Try something like:

Assert.assertTrue(boxes("23").equals("y") || boxes("23").equals("n"));

If you have multiple possible answers, a Set might be easier.

Set<String> possibleAnswers = new HashSet<>();
possibleAnswers.add("y");
possibleAnswers.add("n");
...

Assert.assertTrue(possibleAnswers.contains(boxes("23")));

Answer 3

Assertj is good at this.

import static org.assertj.core.api.Assertions.assertThat;

    assertThat(boxes("23")).isIn("y", "n);

Big plus for assertj compared to hamcrest is easy use of code completion.

Answer 4

Apart from the fact that it is possible (eg see @dev) it is considered to be a bad practice.

Methods returning different results on the same input must (!) contain a source of non-determinism. To resolve this - mock it correctly and there will be only one result.

An explanation for accepting multiple answers could be that the assert method is called from multiple tests just asserting a generic property of the result. Generic properties could be tested more comfortable with Junit Theories .