See https://lists.gnu.org/archive/html/emacs-devel/2018-06/msg00535.html
* test/lisp/electric-tests.el
(electric-pair-whitespace-chomping-2-at-point-4-in-c++-mode-in-strings):
Mark as failing.
:bindings '((electric-pair-skip-whitespace . chomp))
:test-in-comments nil)
+
+;; A test failure introduced by some changes in CC mode. Hopefully CC
+;; mode will sort this out eventually, using some new e-p-m machinery.
+;; See
+;; https://lists.gnu.org/archive/html/emacs-devel/2018-06/msg00535.html
+(setf
+ (ert-test-expected-result-type
+ (ert-get-test 'electric-pair-whitespace-chomping-2-at-point-4-in-c++-mode-in-strings))
+ :failed)
+
(define-electric-pair-test whitespace-chomping-dont-cross-comments
" ( \n\t\t\n ) " "--)------" :expected-string " () \n\t\t\n ) "
:expected-point 4