\Drupal\rest\Plugin\rest\resource\EntityResourceValidationTrait::validate() loops over any validation violations adding them to textual error message:
foreach ($violations as $violation) {
// We strip every HTML from the error message to have a nicer to read
// message on REST responses.
$message .= $violation->getPropertyPath() . ': ' . PlainTextOutput::renderFromHtml($violation->getMessage()) . "\n";
}
throw new UnprocessableEntityHttpException($message);
However, this leaves a trailing newline character at the end of the message.
Trim $message before throwing the exception.
* Write simple patch
* Fix several tests that the patch breaks
* Review patch
* Commit patch
A trailing newline will be removed from some error messages (this may break some tests?)
None.
None.
None.
Needs work
10.1 ✨
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It's likely this issue predates Contrib.social: some issue and comment data are missing.
I did some digging to see the history of this code and if there was any discussion around the new line character. It seems it was first introduced in #1910658: Implement entity validation API for REST entity resources → but there was no discussion about the line break. I think the question is, is this a bug? Does it break anything?