RFR: 8375712: Convert java/lang/runtime tests to use JUnit

[Chen Liang]

On Wed, 21 Jan 2026 16:32:06 GMT, Jan Lahoda <jlahoda at openjdk.org> wrote:

> This PR converts the tests under `test/jdk/java/lang/runtime/` to use JUnit. Mostly converted by the automatic conversion tool, but there's a manual tweak to use `assertThrows` instead of the current manual `try-catch`. Also one manual fix. The changes are in separate commits, which should help reviewing.
> 
> Thanks!

test/jdk/java/lang/runtime/ExactnessConversionsSupportTest.java line 52:

> 50: public class ExactnessConversionsSupportTest {
> 51: 
> 52:     public void main(String[] args) {

Let's remove this main method altogether.

test/jdk/java/lang/runtime/SwitchBootstrapsTest.java line 38:

> 36: import java.lang.classfile.ClassFile;
> 37: 
> 38: import org.junit.jupiter.api.Assertions;

Let's use static imports and remove this import.

test/jdk/java/lang/runtime/SwitchBootstrapsTest.java line 407:

> 405:     @Test
> 406:     public void testNullLookup() throws Throwable {
> 407:         Assertions.assertThrows(NullPointerException.class, () -> {

Can use the static import version instead of fully qualifying here

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PR Review Comment: https://git.openjdk.org/jdk/pull/29350#discussion_r2714076232
PR Review Comment: https://git.openjdk.org/jdk/pull/29350#discussion_r2714088718
PR Review Comment: https://git.openjdk.org/jdk/pull/29350#discussion_r2714087494