From 17bd063a67404a13ff719830336693d7cd7f6d79 Mon Sep 17 00:00:00 2001
From: "F. Jason Park" <jp@neverwas.me>
Date: Sun, 13 Mar 2022 22:39:36 -0700
Subject: [PATCH] Add unit test for erc--switch-to-buffer

* test/lisp/erc/erc-tests.el (erc--switch-to-buffer): Add new test.
(Bug#53617)
---
 test/lisp/erc/erc-tests.el | 57 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 56 insertions(+), 1 deletion(-)

diff --git a/test/lisp/erc/erc-tests.el b/test/lisp/erc/erc-tests.el
index 5603e764547..5a2b90a9402 100644
--- a/test/lisp/erc/erc-tests.el
+++ b/test/lisp/erc/erc-tests.el
@@ -21,7 +21,7 @@
 
 ;;; Code:
 
-(require 'ert)
+(require 'ert-x)
 (require 'erc)
 (require 'erc-ring)
 (require 'erc-networks)
@@ -114,6 +114,61 @@
     (should (get-buffer "#spam"))
     (kill-buffer "#spam")))
 
+(ert-deftest erc--switch-to-buffer ()
+  (defvar erc-modified-channels-alist) ; lisp/erc/erc-track.el
+
+  (let ((proc (start-process "aNet" (current-buffer) "true"))
+        (erc-modified-channels-alist `(("fake") (,(messages-buffer))))
+        (inhibit-message noninteractive)
+        (completion-fail-discreetly t) ; otherwise ^G^G printed to .log file
+        ;;
+        erc-kill-channel-hook erc-kill-server-hook erc-kill-buffer-hook)
+
+    (with-current-buffer (get-buffer-create "server")
+      (erc-mode)
+      (set-process-buffer (setq erc-server-process proc) (current-buffer))
+      (with-current-buffer (get-buffer-create "#chan")
+        (erc-mode)
+        (setq erc-server-process proc))
+      (with-current-buffer (get-buffer-create "#foo")
+        (erc-mode)
+        (setq erc-server-process proc))
+
+      (ert-info ("Channel #chan selectable from server buffer")
+        (ert-simulate-keys (list ?# ?c ?h ?a ?n ?\C-m)
+          (should (string= "#chan" (erc--switch-to-buffer))))))
+
+    (ert-info ("Channel #foo selectable from non-ERC buffer")
+      (ert-simulate-keys (list ?# ?f ?o ?o ?\C-m)
+        (should (string= "#foo" (erc--switch-to-buffer)))))
+
+    (ert-info ("Default selectable")
+      (ert-simulate-keys (list ?\C-m)
+        (should (string= "*Messages*" (erc--switch-to-buffer)))))
+
+    (ert-info ("Extant but non-ERC buffer not selectable")
+      (get-buffer-create "#fake") ; not ours
+      (ert-simulate-keys (kbd "#fake C-m C-a C-k C-m")
+        ;; Initial query fails ~~~~~~^; clearing input accepts default
+        (should (string= "*Messages*" (erc--switch-to-buffer)))))
+
+    (with-current-buffer (get-buffer-create "other")
+      (erc-mode)
+      (setq erc-server-process (start-process "bNet" (current-buffer) "true")))
+
+    (ert-info ("Foreign ERC buffer not selectable")
+      (ert-simulate-keys (kbd "other C-m C-a C-k C-m")
+        (with-current-buffer "server"
+          (should (string= "*Messages*" (erc--switch-to-buffer))))))
+
+    (ert-info ("Any ERC-buffer selectable from non-ERC buffer")
+      (should-not (eq major-mode 'erc-mode))
+      (ert-simulate-keys (list ?o ?t ?h ?e ?r ?\C-m)
+        (should (string= "other" (erc--switch-to-buffer)))))
+
+    (dolist (b '("server" "other" "#chan" "#foo" "#fake"))
+      (kill-buffer b))))
+
 (ert-deftest erc-lurker-maybe-trim ()
   (let (erc-lurker-trim-nicks
         (erc-lurker-ignore-chars "_`"))
-- 
2.39.2