RFR: 8373661: Add edge case tests for Objects.requireNonNull methods [v4]

[Roger Riggs]

On Wed, 17 Dec 2025 11:50:53 GMT, eunbin son <duke at openjdk.org> wrote:

>> ## Summary
>> Adds comprehensive edge case tests for `Objects.requireNonNull`, 
>> `requireNonNullElse`, and `requireNonNullElseGet` methods to improve 
>> test coverage.
>> 
>> ## Problem
>> The current test suite for `Objects.requireNonNull` methods covers 
>> basic cases but lacks edge case coverage.
>> 
>> ## Solution
>> This PR adds tests for the following edge cases:
>> - requireNonNull with null Supplier parameter
>> - requireNonNull with Supplier that throws exception
>> - requireNonNullElse with both arguments null
>> - requireNonNullElseGet with null supplier
>> - requireNonNullElseGet with supplier returning null
>> 
>> ## Issue
>> Fixes JDK-8373661
>> 
>> **JBS Issue Link**: https://bugs.java.com/bugdatabase/view_bug?bug_id=JDK-8373661
>> 
>> ## Type of Change
>> - [x] Test addition/modification
>> - [ ] Bug fix
>> - [ ] New feature
>> - [ ] Documentation improvement
>> - [ ] Refactoring
>> 
>> ## Testing
>> 
>> make test TEST="jtreg:test/jdk/java/util/Objects"
>
> eunbin son has updated the pull request incrementally with one additional commit since the last revision:
> 
>   8373661: Use assertSame for exception instance verification
>   
>   Updated testRequireNonNullWithSupplierThrowingException to allocate
>   the exception outside of the lambda and use assertSame to verify
>   the same exception instance is thrown, as suggested by @liach.
>   
>   This provides a more precise verification that the exception from
>   the supplier is thrown directly, not wrapped.
>   
>   Thanks to @liach for the feedback.

Thanks for the conversion.
It may be useful to force some of the asserts to fail and check that the error messages are readable.

test/jdk/java/util/Objects/BasicObjectsTest.java line 31:

> 29:  */
> 30: 
> 31: import static org.junit.jupiter.api.Assertions.*;

OpenJdk style is to avoid wildcard imports, especially for small numbers.

test/jdk/java/util/Objects/BasicObjectsTest.java line 34:

> 32: import org.junit.jupiter.api.Test;
> 33: import java.util.*;
> 34: import java.util.function.*;

Please expand these too, though they are pre-existing.

test/jdk/java/util/Objects/BasicObjectsTest.java line 49:

> 47:                 assertEquals(expected, result,
> 48:                     String.format("When equating %s to %s, got %b instead of %b",
> 49:                                   a, b, result, expected));

Since the JUnit assertEquals already prints the expected and actual, please simplify, retaining a message that identifies the test.

test/jdk/java/util/Objects/BasicObjectsTest.java line 134:

> 132:                 @Override
> 133:                 public String toString() {
> 134:                     throw new RuntimeException();

In Junit, this should probably call Assertions.fail(...)

test/jdk/java/util/Objects/BasicObjectsTest.java line 208:

> 206:             NullPointerException.class,
> 207:             () -> testFunc.apply(null),
> 208:             testFuncName + " should throw NPE");

AssertThrows will already include the message that it should throw; the message argument can be simplified to just the testFuncName.

test/jdk/java/util/Objects/BasicObjectsTest.java line 218:

> 216:             "isNull(null) should return true");
> 217:         assertFalse(Objects.isNull(Objects.class),
> 218:             "isNull(Objects.class) should return false");

Could be simplifed with Assertions.assertNull or assertNonNull.  Here and elsewhere in this test.

-------------

PR Review: https://git.openjdk.org/jdk/pull/28845#pullrequestreview-3589611390
PR Review Comment: https://git.openjdk.org/jdk/pull/28845#discussion_r2628605220
PR Review Comment: https://git.openjdk.org/jdk/pull/28845#discussion_r2628606965
PR Review Comment: https://git.openjdk.org/jdk/pull/28845#discussion_r2628616800
PR Review Comment: https://git.openjdk.org/jdk/pull/28845#discussion_r2628625305
PR Review Comment: https://git.openjdk.org/jdk/pull/28845#discussion_r2628633438
PR Review Comment: https://git.openjdk.org/jdk/pull/28845#discussion_r2628642090