Add hook to skip asserting x-content equivalence

[jasontedor]

This commit adds a hook to AbstractSerializingTestCase to enable skipping asserting that the x-content of the test instance and an instance parsed from the x-content of the test instance are the same. While we usually expect these to be the same, they will not be the same when exceptions are involved because the x-content there is lossy.

[elasticmachine]

Pinging @elastic/es-core-infra

[jasontedor]

This is the key change, from true to use the assertToXContentEquivalence hook. This is why I like long parameter lists on a single line per parameter. 😇

Were this method already formatted on a single line per parameter, the diff would have made this change obvious:

diff --git a/test/framework/src/main/java/org/elasticsearch/test/AbstractSerializingTestCase.java b/test/framework/src/main/java/org/elasticsearch/test/AbstractSerializingTestCase.java
index 7e945a8414c..5aeb30bfdbd 100644
--- a/test/framework/src/main/java/org/elasticsearch/test/AbstractSerializingTestCase.java
+++ b/test/framework/src/main/java/org/elasticsearch/test/AbstractSerializingTestCase.java
@@ -44,7 +44,7 @@ public abstract class AbstractSerializingTestCase<T extends ToXContent & Writeab
                 this::createParser,
                 this::doParseInstance,
                 this::assertEqualInstances,
-                true,
+                assertToXContentEquivalence(),
                 getToXContentParams());
     }
 

[martijnvg]

Good point!

[martijnvg]

LGTM

[jasontedor]

Thanks for reviewing @javanna and @martijnvg.