RFR: 8346106: Verify.checkEQ: testing utility for recursive value verification

[theoweidmannoracle]

On Thu, 12 Dec 2024 15:43:53 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> In testing, we often generate "golden" values, and then compare the results with it. This requires comparison loops etc in every test. I would like to create a dedicated facility for this, to simplify testing in the future. This is also preparation for [JDK-8344942](https://bugs.openjdk.org/browse/JDK-8344942), the Template framework.
>> 
>> I have written code like this in various tests before, see:
>> `test/hotspot/jtreg/compiler/loopopts/superword/TestAlignVectorFuzzer.java`
>> `./test/hotspot/jtreg/compiler/loopopts/superword/TestMemorySegment.java`
>> `test/hotspot/jtreg/compiler/loopopts/superword/TestIndependentPacksWithCyclicDependency.java`.
>> 
>> It is now time to make a proper facility, so I can save time when writing tests in the future.
>> 
>> A related PR, for value generation: https://github.com/openjdk/jdk/pull/22716
>
> test/hotspot/jtreg/compiler/lib/verify/Verify.java line 42:
> 
>> 40:     public static void checkEQ(Object a, Object b) {
>> 41:         checkEQ(a, b, "");
>> 42:     }
> 
> Note: this is the only entry point to the Utility.

Maybe this note could be added to the documentation comment?

> test/hotspot/jtreg/testlibrary_tests/verify/examples/TestVerifyInCheckMethod.java line 75:
> 
>> 73:     public static void check(Object result) {
>> 74:         Verify.checkEQ(result, GOLD);
>> 75:     }
> 
> Note: this is how we might generate Templates in the future: Using the `@Check` method with `Verify.checkEQ`. It allows the template to basically return whatever it wants, and it will be verified with the interpreter run.

Could we go even further and annotate this directly at the test method? For example:


     @Test
     @Arguments(setup = "setup")
     @VerifyResult(expected = GOLD)
     public static Object test(int[] a, float b) {
         for (int i = 0; i < a.length; i++) {
             a[i] = (int)(a[i] * b);
         }
         // Since we have more than one value, we wrap them in an Object[].
         return new Object[] {a, b};
     }

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

PR Review Comment: https://git.openjdk.org/jdk/pull/22715#discussion_r1889745144
PR Review Comment: https://git.openjdk.org/jdk/pull/22715#discussion_r1889765010