Apply colorization on actual/expected test output

For matchers like matcher-combinators that rely on that.

Author: plexus

Diff for: CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Changes
 
+* [#3177](https://github.com/clojure-emacs/cider/pull/3177) Apply ANSI colorization to test assertion output
 * Use clojure-mode [5.14.0](https://github.com/clojure-emacs/clojure-mode/blob/v5.14.0/CHANGELOG.md#5140-2022-03-07).
 * [#3170](https://github.com/clojure-emacs/cider/issues/3170) Skip ensure repl available on xref functions.
 * [#3173](https://github.com/clojure-emacs/cider/issues/3173) Locally remove `cider-complete-at-point` from `completion-at-point-functions` instead of killing it as a local variable.

Diff for: cider-test.el

@@ -28,6 +28,7 @@
 
 ;;; Code:
 
+(require 'ansi-color)
 (require 'button)
 (require 'cl-lib)
 (require 'easymenu)
@@ -395,9 +396,11 @@ With the actual value, the outermost '(not ...)' s-expression is removed."
                 (insert-align-label (s)
                   (insert (format "%12s" s)))
                 (insert-rect (s)
-                  (insert-rectangle (thread-first s
-                                      cider-font-lock-as-clojure
-                                      (split-string "\n")))
+                  (let ((start (point)))
+                    (insert-rectangle (thread-first s
+                                        cider-font-lock-as-clojure
+                                        (split-string "\n")))
+                    (ansi-color-apply-on-region start (point)))
                   (beginning-of-line)))
         (cider-propertize-region (cider-intern-keys (cdr test))
           (let ((beg (point))