Add test for align-regexp

* test/lisp/align-tests.el (align-regexp): New test.
* test/lisp/align-resources/align-regexp.erts: New file.

* test/lisp/align-resources/c-mode.erts: Add new test case.

test/lisp/align-resources/align-regexp.erts

@@ -0,0 +1,13 @@
+Name: align function declaration
+
+=-=
+Fred (123) 456-7890
+Alice (123) 456-7890
+Mary-Anne (123) 456-7890
+Joe (123) 456-7890
+=-=
+Fred      (123) 456-7890
+Alice     (123) 456-7890
+Mary-Anne (123) 456-7890
+Joe       (123) 456-7890
+=-=-=

test/lisp/align-resources/c-mode.erts

@@ -9,3 +9,15 @@ int
 main (int	 argc,
       char	*argv[]);
 =-=-=
+
+Name: example from Commentary
+
+=-=
+    int a = 1;
+    short foo = 2;
+    double blah = 4;
+=-=
+    int		a	=	1;
+    short	foo	=	2;
+    double	blah	=	4;
+=-=-=

test/lisp/align-tests.el

@@ -25,6 +25,8 @@
 (require 'ert-x)
 (require 'align)
 
+;;;; align
+
 (defun test-align-transform-fun (function)
   (lambda ()
     (funcall function)
@@ -56,6 +58,15 @@
     (ert-test-erts-file (ert-resource-file "conf-toml-mode.erts")
                         (test-align-transform-fun #'conf-toml-mode))))
 
+;;;; align-regexp
+
+(ert-deftest align-regexp ()
+  (let ((indent-tabs-mode nil))
+    (ert-test-erts-file (ert-resource-file "align-regexp.erts")
+                        (lambda ()
+                          (align-regexp (point-min) (point-max)
+                                        "\\(\\s-*\\)(")))))
+
 (provide 'align-tests)
 
 ;;; align-tests.el ends here