How to test that no exception is thrown?

To test that no exception is thrown in a Java method, you can use the assertDoesNotThrow method from the org.junit.jupiter.api.Assertions class (part of the JUnit 5 library).

Here is an example of how to use assertDoesNotThrow to test that a method does not throw an exception:

import org.junit.jupiter.api.Assertions;

public class NoExceptionTest {

    @Test
    public void testNoException() {
        assertDoesNotThrow(() -> {
            // code that is expected to not throw an exception
        });
    }

}

The assertDoesNotThrow method takes a Executable lambda as an argument, which is a block of code that is expected to not throw any exceptions. If the code block does throw an exception, assertDoesNotThrow will fail the test.

You can also use the try-catch statement to test that a method does not throw an exception:

try {
    // code that is expected to not throw an exception
} catch (Exception e) {
    fail("Exception was thrown");
}

In this case, the test will fail if an exception is thrown in the try block.

I hope this helps. Let me know if you have any questions.