1 files changed, 64 insertions, 0 deletions
diff --git a/test/lisp/erc/erc-tests.el b/test/lisp/erc/erc-tests.el
index 26e14b98e91..d13397274aa 100644
--- a/test/lisp/erc/erc-tests.el
+++ b/test/lisp/erc/erc-tests.el
@@ -23,6 +23,7 @@
 
 (require 'ert)
 (require 'erc)
+(require 'erc-ring)
 
 (ert-deftest erc--read-time-period ()
   (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "")))
@@ -45,3 +46,66 @@
 
   (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "1d")))
     (should (equal (erc--read-time-period "foo: ") 86400))))
+
+(ert-deftest erc-ring-previous-command-base-case ()
+  (ert-info ("Create ring when nonexistent and do nothing")
+    (let (erc-input-ring
+          erc-input-ring-index)
+      (erc-previous-command)
+      (should (ring-p erc-input-ring))
+      (should (zerop (ring-length erc-input-ring)))
+      (should-not erc-input-ring-index)))
+  (should-not erc-input-ring))
+
+(ert-deftest erc-ring-previous-command ()
+  (with-current-buffer (get-buffer-create "*#fake*")
+    (erc-mode)
+    (insert "\n\n")
+    (setq erc-input-marker (make-marker) ; these are all local
+          erc-insert-marker (make-marker)
+          erc-send-completed-hook nil)
+    (set-marker erc-insert-marker (point-max))
+    (erc-display-prompt)
+    (should (= (point) erc-input-marker))
+    (add-hook 'erc-pre-send-functions #'erc-add-to-input-ring nil t)
+    ;;
+    (cl-letf (((symbol-function 'erc-process-input-line)
+               (lambda (&rest _)
+                 (insert-before-markers
+                  (erc-display-message-highlight 'notice "echo: one\n"))))
+              ((symbol-function 'erc-command-no-process-p)
+               (lambda (&rest _) t)))
+      (ert-info ("Create ring, populate, recall")
+        (insert "/one")
+        (erc-send-current-line)
+        (should (ring-p erc-input-ring))
+        (should (zerop (ring-member erc-input-ring "/one"))) ; equal
+        (should (save-excursion (forward-line -1) (goto-char (point-at-bol))
+                                (looking-at-p "[*]+ echo: one")))
+        (should-not erc-input-ring-index)
+        (erc-bol)
+        (should (looking-at "$"))
+        (erc-previous-command)
+        (erc-bol)
+        (should (looking-at "/one"))
+        (should (zerop erc-input-ring-index)))
+      (ert-info ("Back to one")
+        (should (= (ring-length erc-input-ring) (1+ erc-input-ring-index)))
+        (erc-previous-command)
+        (should-not erc-input-ring-index)
+        (erc-bol)
+        (should (looking-at "$"))
+        (should (equal (ring-ref erc-input-ring 0) "/one")))
+      (ert-info ("Swap input after prompt with previous (#bug46339)")
+        (insert "abc")
+        (erc-previous-command)
+        (should (= 1 erc-input-ring-index))
+        (erc-bol)
+        (should (looking-at "/one"))
+        (should (equal (ring-ref erc-input-ring 0) "abc"))
+        (should (equal (ring-ref erc-input-ring 1) "/one"))
+        (erc-next-command)
+        (erc-bol)
+        (should (looking-at "abc")))))
+  (when noninteractive
+    (kill-buffer "*#fake*")))