Incorrect use of UnprocessableHttpEntityException in EntityResource::deserialize()

Thanks @garphy!

+++ b/core/modules/jsonapi/src/Controller/EntityResource.php
@@ -822,10 +822,10 @@ protected function deserialize(ResourceType $resource_type, Request $request, $c
     catch (UnexpectedValueException $e) {
...
+      throw new UnprocessableHttpEntityException($e);
     }
     catch (InvalidArgumentException $e) {
-      throw new UnprocessableHttpEntityException($e->getMessage());
+      throw new UnprocessableHttpEntityException($e);
     }

I'd swear I have a patch for this already…

Yep, found it, over at #3042124-23: [regression] Empty response body when user is an administrator and an exception is thrown; some traces cannot be encoded because of recursion detection.. I think that's the correct solution.

If we want to go with this solution, then we'll need to update the @throws entry on the \Drupal\jsonapi\Controller\EntityResource::deserialize() docs.

Per #7.

Thanks @Wim Leers! LGTM. Nope, see below.

I lied, we need to reroll the tests in #2. They should probably be moved to JsonapiRegressionTest too.

The actual fix in #8 looks good to me; back to @Wim Leers to review the reroll of @garphy's tests.

The test only patch is the interdiff.

1. +++ b/core/modules/jsonapi/tests/src/Functional/JsonApiRegressionTest.php
   @@ -989,4 +989,43 @@ public function testLeakedCacheMetadataViaRdfFromIssue3053827() {
   +   * Ensure that a 422 Unprocessable Entity for invalid POST data.
   

   🤓 Missing a verb. Fixed. ✅

2. +++ b/core/modules/jsonapi/tests/src/Functional/JsonApiRegressionTest.php
   @@ -989,4 +989,43 @@ public function testLeakedCacheMetadataViaRdfFromIssue3053827() {
   +    // Set up some invalid data.
   ...
   +    // Set up a test user.
   ...
   +    // Send the invalid request.
   

   🤔This is quite different compared to the other test methods in this class. Let's follow the same pattern. Done. ✅

All of that is just adding docs and reordering logic that @garphy wrote, so that doesn't preclude me from RTBC'ing :)

Needs a re-roll. Not sure what happened to DrupalCI marking issues CNW.

Rebased.

Committed e0a8d33 and pushed to 8.8.x. Thanks!