RFR: JDK-8326389: [test] improve assertEquals failure output [v3]

[Jaikiran Pai]

On Thu, 22 Feb 2024 16:01:19 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

>> Currently assertEquals has in the failure case sometimes confusing output like :
>> 
>> java.lang.RuntimeException: VM output should contain exactly one RTM locking statistics entry for method compiler.rtm.locking.TestRTMTotalCountIncrRate$Test:🔒 expected 0 to equal 1
>>        at jdk.test.lib.Asserts.fail(Asserts.java:634)
>>        at jdk.test.lib.Asserts.assertEquals(Asserts.java:205)
>> 
>> (I don't think we really expected that for some reason 0 equals 1)
>> This should be improved.
>
> Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:
> 
>   assertEquals adjust output

Hello Matthias, the proposal to improve that failure message looks OK to me. However, I feel that the newly proposed error message isn't too different than what it was earlier. Perhaps, we could do something like:


diff --git a/test/lib/jdk/test/lib/Asserts.java b/test/lib/jdk/test/lib/Asserts.java
index d503ea8e544..3b45d7f4129 100644
--- a/test/lib/jdk/test/lib/Asserts.java
+++ b/test/lib/jdk/test/lib/Asserts.java
@@ -199,10 +199,11 @@ public static void assertEquals(Object lhs, Object rhs) {
      */
     public static void assertEquals(Object lhs, Object rhs, String msg) {
         if ((lhs != rhs) && ((lhs == null) || !(lhs.equals(rhs)))) {
-            msg = Objects.toString(msg, "assertEquals")
-                    + ": expected " + Objects.toString(lhs)
-                    + " to equal " + Objects.toString(rhs);
-            fail(msg);
+            if (msg != null) {
+                fail(msg);
+            } else {
+                fail("assertEquals expected: " + lhs + " but was: " + rhs);
+            }
         }
     }



This is similar to what other test libraries usually report for such failures.

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PR Comment: https://git.openjdk.org/jdk/pull/17952#issuecomment-1962337015