Add ability to use datasource in class with @Nested Tests

[kiryl-naurotski]

Overview

Right now tests located in a @Nested class run only after tests in enclosing classes have finished their execution. Such behavior doesn't allow one to run test classes with different values.

If we run the following test class:

public class StackTest {
    static int number;

    @ParameterizedTest
    @ValueSource(ints = {1, 2, 3, 4})
    @DisplayName("is instantiated with new Stack()")
    void isInstantiatedWithNew(int numbers) {
        number = numbers;
    }

    @Nested
    @DisplayName("when new")
    class WhenNew {

        @Test
        @DisplayName("is empty")
        void isEmpty() {
            System.out.println("Is empty: " + number);
            assertTrue(true);
        }

        @Nested
        @DisplayName("after pushing an element")
        class AfterPushing {

            @Test
            @DisplayName("it is no longer empty")
            void isNotEmpty() {
                System.out.println("is not empty: " + number);
                assertTrue(true);
            }
        }
    }
}

... we will see that all nested tests received only the last number (4).

Is there any way to send all provided numbers to nested tests?

Related Issues

• Introduce extension API for container templates #871
• Introduce support for parameterized containers (classes, records, etc) #878

[sbrannen]

Is there any way to send all provided numbers to nested tests?

There is no built-in mechanism for achieving that.

If you just want the list of numbers, you could of course store them in a field of type List<Integer> instead of only storing the last one in a field of type int.

[sbrannen]

The ability to run test classes with different values (i.e., to parameterize test classes) will be introduced in conjunction with #871/#878.

I am therefore closing this issue as a duplicate.

Feel free to provide further input in #871/#878.

Thanks!

[kiryl-naurotski]

Numbers was just an example.
On the project I use root test to trigger flow and check if it triggered successfully.
Nested tests I use to check output from each component in the flow.

[sbrannen]

Do the proposals in #871 and #878 address your needs?

[kiryl-naurotski]

Also for some reason class with nested tests runs faster, than class with single test with the same number of checks and actions

[sbrannen]

Also for some reason class with nested tests runs faster, than class with single test with the same number of checks and actions

I cannot imagine how that could be the case since the execution of a class along with its nested classes technically requires more work.

So, if you can provide a small project that proves that, we'd be interested in seeing that (in a separate GitHub issue).

Cheers

[kiryl-naurotski]

Do the proposals in #871 and #878 address your needs?

It seems that yes

[sbrannen]

It seems that yes

Great. Thanks for the feedback!