;;; erc-tests.el --- Tests for erc.  -*- lexical-binding:t -*-

;; Copyright (C) 2020-2023 Free Software Foundation, Inc.

;; Author: Lars Ingebrigtsen <larsi@gnus.org>

;; This file is part of GNU Emacs.

;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.

;;; Code:

(require 'ert-x)
(require 'erc)
(require 'erc-ring)

(ert-deftest erc--read-time-period ()
  (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "")))
    (should (equal (erc--read-time-period "foo: ") nil)))

  (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "   ")))
    (should (equal (erc--read-time-period "foo: ") nil)))

  (cl-letf (((symbol-function 'read-string) (lambda (&rest _) " 432 ")))
    (should (equal (erc--read-time-period "foo: ") 432)))

  (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "432")))
    (should (equal (erc--read-time-period "foo: ") 432)))

  (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "1h")))
    (should (equal (erc--read-time-period "foo: ") 3600)))

  (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "1h10s")))
    (should (equal (erc--read-time-period "foo: ") 3610)))

  (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "1d")))
    (should (equal (erc--read-time-period "foo: ") 86400))))

(ert-deftest erc-with-all-buffers-of-server ()
  (let (proc-exnet
        proc-onet
        erc-kill-channel-hook erc-kill-server-hook erc-kill-buffer-hook)

    (with-current-buffer (get-buffer-create "OtherNet")
      (erc-mode)
      (setq proc-onet (start-process "sleep" (current-buffer) "sleep" "1")
            erc-server-process proc-onet
            erc-network 'OtherNet)
      (set-process-query-on-exit-flag erc-server-process nil))

    (with-current-buffer (get-buffer-create "ExampleNet")
      (erc-mode)
      (setq proc-exnet (start-process "sleep" (current-buffer) "sleep" "1")
            erc-server-process proc-exnet
            erc-network 'ExampleNet)
      (set-process-query-on-exit-flag erc-server-process nil))

    (with-current-buffer (get-buffer-create "#foo")
      (erc-mode)
      (setq erc-server-process proc-exnet)
      (setq erc--target (erc--target-from-string "#foo")))

    (with-current-buffer (get-buffer-create "#spam")
      (erc-mode)
      (setq erc-server-process proc-onet)
      (setq erc--target (erc--target-from-string "#spam")))

    (with-current-buffer (get-buffer-create "#bar")
      (erc-mode)
      (setq erc-server-process proc-onet)
      (setq erc--target (erc--target-from-string "#bar")))

    (with-current-buffer (get-buffer-create "#baz")
      (erc-mode)
      (setq erc-server-process proc-exnet)
      (setq erc--target (erc--target-from-string "#baz")))

    (should (eq (get-buffer-process "ExampleNet") proc-exnet))
    (erc-with-all-buffers-of-server (get-buffer-process "ExampleNet") nil
      (kill-buffer))

    (should-not (get-buffer "ExampleNet"))
    (should-not (get-buffer "#foo"))
    (should-not (get-buffer "#baz"))
    (should (get-buffer "OtherNet"))
    (should (get-buffer "#bar"))
    (should (get-buffer "#spam"))

    (let* ((test (lambda () (not (string= (buffer-name) "#spam"))))
           (calls 0)
           (get-test (lambda () (cl-incf calls) test)))

      (erc-with-all-buffers-of-server proc-onet (funcall get-test)
        (kill-buffer))

      (should (= calls 1)))

    (should-not (get-buffer "OtherNet"))
    (should-not (get-buffer "#bar"))
    (should (get-buffer "#spam"))
    (kill-buffer "#spam")))

(ert-deftest erc-with-server-buffer ()
  (setq erc-away 1)
  (erc-tests--set-fake-server-process "sleep" "1")

  (let (calls)
    (advice-add 'buffer-local-value :after (lambda (&rest r) (push r calls))
                '((name . erc-with-server-buffer)))

    (should (= 1 (erc-with-server-buffer erc-away)))
    (should (equal (pop calls) (list 'erc-away (current-buffer))))

    (should (= 1 (erc-with-server-buffer (ignore 'me) erc-away)))
    (should-not calls)

    (advice-remove 'buffer-local-value 'erc-with-server-buffer)))

(ert-deftest erc--with-dependent-type-match ()
  (should (equal (macroexpand-1
                  '(erc--with-dependent-type-match (repeat face) erc-match))
                 '(backquote-list*
                   'repeat :match (lambda (w v)
                                    (require 'erc-match)
                                    (widget-editable-list-match w v))
                   '(face)))))

(defun erc-tests--send-prep ()
  ;; Caller should probably shadow `erc-insert-modify-hook' or
  ;; populate user tables for erc-button.
  (erc-mode)
  (erc--initialize-markers (point) nil)
  (should (= (point) erc-input-marker)))

(defun erc-tests--set-fake-server-process (&rest args)
  (setq erc-server-process
        (apply #'start-process (car args) (current-buffer) args))
  (set-process-query-on-exit-flag erc-server-process nil))

(ert-deftest erc-hide-prompt ()
  (let (erc-kill-channel-hook erc-kill-server-hook erc-kill-buffer-hook)

    (with-current-buffer (get-buffer-create "ServNet")
      (erc-tests--send-prep)
      (goto-char erc-insert-marker)
      (should (looking-at-p (regexp-quote erc-prompt)))
      (erc-tests--set-fake-server-process "sleep" "1")
      (set-process-sentinel erc-server-process #'ignore)
      (setq erc-network 'ServNet)
      (set-process-query-on-exit-flag erc-server-process nil))

    (with-current-buffer (get-buffer-create "#chan")
      (erc-tests--send-prep)
      (goto-char erc-insert-marker)
      (should (looking-at-p (regexp-quote erc-prompt)))
      (setq erc-server-process (buffer-local-value 'erc-server-process
                                                   (get-buffer "ServNet"))
            erc--target (erc--target-from-string "#chan")))

    (with-current-buffer (get-buffer-create "bob")
      (erc-tests--send-prep)
      (goto-char erc-insert-marker)
      (should (looking-at-p (regexp-quote erc-prompt)))
      (setq erc-server-process (buffer-local-value 'erc-server-process
                                                   (get-buffer "ServNet"))
            erc--target (erc--target-from-string "bob")))

    (ert-info ("Value: t (default)")
      (should (eq erc-hide-prompt t))
      (with-current-buffer "ServNet"
        (should (= (point) erc-insert-marker))
        (erc--hide-prompt erc-server-process)
        (should (string= ">" (get-text-property (point) 'display))))

      (with-current-buffer "#chan"
        (goto-char erc-insert-marker)
        (should (string= ">" (get-text-property (point) 'display)))
        (should (memq #'erc--unhide-prompt-on-self-insert pre-command-hook))
        (goto-char erc-input-marker)
        (ert-simulate-command '(self-insert-command 1 ?/))
        (goto-char erc-insert-marker)
        (should-not (get-text-property (point) 'display))
        (should-not (memq #'erc--unhide-prompt-on-self-insert
                          pre-command-hook)))

      (with-current-buffer "bob"
        (goto-char erc-insert-marker)
        (should (string= ">" (get-text-property (point) 'display)))
        (should (memq #'erc--unhide-prompt-on-self-insert pre-command-hook))
        (goto-char erc-input-marker)
        (ert-simulate-command '(self-insert-command 1 ?/))
        (goto-char erc-insert-marker)
        (should-not (get-text-property (point) 'display))
        (should-not (memq #'erc--unhide-prompt-on-self-insert
                          pre-command-hook)))

      (with-current-buffer "ServNet"
        (should (get-text-property erc-insert-marker 'display))
        (should (memq #'erc--unhide-prompt-on-self-insert pre-command-hook))
        (erc--unhide-prompt)
        (should-not (memq #'erc--unhide-prompt-on-self-insert
                          pre-command-hook))
        (should-not (get-text-property erc-insert-marker 'display))))

    (ert-info ("Value: server")
      (setq erc-hide-prompt '(server))
      (with-current-buffer "ServNet"
        (erc--hide-prompt erc-server-process)
        (should (eq (get-text-property erc-insert-marker 'erc-prompt) 'hidden))
        (should (string= ">" (get-text-property erc-insert-marker 'display))))

      (with-current-buffer "#chan"
        (should-not (get-text-property erc-insert-marker 'display)))

      (with-current-buffer "bob"
        (should-not (get-text-property erc-insert-marker 'display)))

      (with-current-buffer "ServNet"
        (erc--unhide-prompt)
        (should (eq (get-text-property erc-insert-marker 'erc-prompt) t))
        (should-not (get-text-property erc-insert-marker 'display))))

    (ert-info ("Value: channel")
      (setq erc-hide-prompt '(channel))
      (with-current-buffer "ServNet"
        (erc--hide-prompt erc-server-process)
        (should-not (get-text-property erc-insert-marker 'display)))

      (with-current-buffer "bob"
        (should-not (get-text-property erc-insert-marker 'display)))

      (with-current-buffer "#chan"
        (should (string= ">" (get-text-property erc-insert-marker 'display)))
        (should (eq (get-text-property erc-insert-marker 'erc-prompt) 'hidden))
        (erc--unhide-prompt)
        (should (eq (get-text-property erc-insert-marker 'erc-prompt) t))
        (should-not (get-text-property erc-insert-marker 'display))))

    (ert-info ("Value: query")
      (setq erc-hide-prompt '(query))
      (with-current-buffer "ServNet"
        (erc--hide-prompt erc-server-process)
        (should-not (get-text-property erc-insert-marker 'display)))

      (with-current-buffer "bob"
        (should (string= ">" (get-text-property erc-insert-marker 'display)))
        (should (eq (get-text-property erc-insert-marker 'erc-prompt) 'hidden))
        (erc--unhide-prompt)
        (should (eq (get-text-property erc-insert-marker 'erc-prompt) t))
        (should-not (get-text-property erc-insert-marker 'display)))

      (with-current-buffer "#chan"
        (should-not (get-text-property erc-insert-marker 'display))))

    (ert-info ("Value: nil")
      (setq erc-hide-prompt nil)
      (with-current-buffer "ServNet"
        (erc--hide-prompt erc-server-process)
        (should-not (get-text-property erc-insert-marker 'display)))

      (with-current-buffer "bob"
        (should-not (get-text-property erc-insert-marker 'display)))

      (with-current-buffer "#chan"
        (should-not (get-text-property erc-insert-marker 'display))
        (erc--unhide-prompt) ; won't blow up when prompt already showing
        (should-not (get-text-property erc-insert-marker 'display))))

    (when noninteractive
      (kill-buffer "#chan")
      (kill-buffer "bob")
      (kill-buffer "ServNet"))))

(ert-deftest erc--refresh-prompt ()
  (let* ((counter 0)
         (erc-prompt (lambda ()
                       (format "%s %d>"
                               (erc-format-target-and/or-network)
                               (cl-incf counter))))
         erc-accidental-paste-threshold-seconds
         erc-insert-modify-hook
         (erc-modules (remq 'stamp erc-modules))
         (erc-send-input-line-function #'ignore)
         (erc--input-review-functions erc--input-review-functions)
         erc-send-completed-hook)

    (ert-info ("Server buffer")
      (with-current-buffer (get-buffer-create "ServNet")
        (erc-tests--send-prep)
        (goto-char erc-insert-marker)
        (should (looking-at-p "ServNet 3>"))
        (erc-tests--set-fake-server-process "sleep" "1")
        (set-process-sentinel erc-server-process #'ignore)
        (setq erc-network 'ServNet
              erc-server-current-nick "tester"
              erc-networks--id (erc-networks--id-create nil)
              erc-server-users (make-hash-table :test 'equal))
        (set-process-query-on-exit-flag erc-server-process nil)
        ;; Incoming message redraws prompt
        (erc-display-message nil 'notice nil "Welcome")
        (should (looking-at-p (rx "*** Welcome")))
        (forward-line)
        (should (looking-at-p "ServNet 4>"))
        ;; Say something
        (goto-char erc-input-marker)
        (insert "Howdy")
        (erc-send-current-line)
        (save-excursion (forward-line -1)
                        (should (looking-at "No target"))
                        (forward-line -1)
                        (should (looking-at "<tester> Howdy")))
        (should (looking-back "ServNet 6> "))
        (should (= erc-input-marker (point)))
        ;; Space after prompt is unpropertized
        (should (get-text-property (1- erc-input-marker) 'erc-prompt))
        (should-not (get-text-property erc-input-marker 'erc-prompt))
        ;; No sign of old prompts
        (save-excursion
          (goto-char (point-min))
          (should-not (search-forward (rx (any "3-5") ">") nil t)))))

    (ert-info ("Channel buffer")
      (with-current-buffer (get-buffer-create "#chan")
        (erc-tests--send-prep)
        (goto-char erc-insert-marker)
        (should (looking-at-p "#chan 9>"))
        (goto-char erc-input-marker)
        (setq erc-server-process (buffer-local-value 'erc-server-process
                                                     (get-buffer "ServNet"))
              erc-networks--id (erc-with-server-buffer erc-networks--id)
              erc--target (erc--target-from-string "#chan")
              erc-default-recipients (list "#chan")
              erc-channel-users (make-hash-table :test 'equal))
        (erc-update-current-channel-member "alice" "alice")
        (erc-update-current-channel-member "bob" "bob")
        (erc-update-current-channel-member "tester" "tester")
        (erc-display-message nil nil (current-buffer)
                             (erc-format-privmessage "alice" "Hi" nil t))
        (should (looking-back "#chan@ServNet 10> "))
        (goto-char erc-input-marker)
        (insert "Howdy")
        (erc-send-current-line)
        (save-excursion (forward-line -1)
                        (should (looking-at "<tester> Howdy")))
        (should (looking-back "#chan@ServNet 11> "))
        (should (= (point) erc-input-marker))
        (insert "/query bob")
        (let (erc-modules)
          (erc-send-current-line))
        ;; Last command not inserted
        (save-excursion (forward-line -1)
                        (should (looking-at "<tester> Howdy")))
        ;; Query does not redraw (nor /help, only message input)
        (should (looking-back "#chan@ServNet 11> "))
        ;; No sign of old prompts
        (save-excursion
          (goto-char (point-min))
          (should-not (search-forward (rx (or "9" "10") ">") nil t)))))

    (ert-info ("Query buffer")
      (with-current-buffer (get-buffer "bob")
        (goto-char erc-insert-marker)
        (should (looking-at-p "bob@ServNet 14>"))
        (goto-char erc-input-marker)
        (erc-display-message nil nil (current-buffer)
                             (erc-format-privmessage "bob" "Hi" nil t))
        (should (looking-back "bob@ServNet 15> "))
        (goto-char erc-input-marker)
        (insert "Howdy")
        (erc-send-current-line)
        (save-excursion (forward-line -1)
                        (should (looking-at "<tester> Howdy")))
        (should (looking-back "bob@ServNet 16> "))
        ;; No sign of old prompts
        (save-excursion
          (goto-char (point-min))
          (should-not (search-forward (rx (or "14" "15") ">") nil t)))))

    (when noninteractive
      (kill-buffer "#chan")
      (kill-buffer "bob")
      (kill-buffer "ServNet"))))

(ert-deftest erc--initialize-markers ()
  (let ((proc (start-process "true" (current-buffer) "true"))
        erc-modules
        erc-connect-pre-hook
        erc-insert-modify-hook
        erc-kill-channel-hook erc-kill-server-hook erc-kill-buffer-hook)
    (set-process-query-on-exit-flag proc nil)
    (erc-mode)
    (setq erc-server-process proc
          erc-networks--id (erc-networks--id-create 'foonet))
    (erc-open "localhost" 6667 "tester" "Tester" nil
              "fake" nil "#chan" proc nil "user" nil)
    (with-current-buffer (should (get-buffer "#chan"))
      (should (= ?\n (char-after 1)))
      (should (= ?E (char-after erc-insert-marker)))
      (should (= 3 (marker-position erc-insert-marker)))
      (should (= 8 (marker-position erc-input-marker)))
      (should (= 8 (point-max)))
      (should (= 8 (point)))
      ;; These prompt properties are a continual source of confusion.
      ;; Including the literal defaults here can hopefully serve as a
      ;; quick reference for anyone operating in that area.
      (should (equal (buffer-string)
                     #("\n\nERC> "
                       2 6 ( font-lock-face erc-prompt-face
                             rear-nonsticky t
                             erc-prompt t
                             field erc-prompt
                             front-sticky t
                             read-only t)
                       6 7 ( rear-nonsticky t
                             erc-prompt t
                             field erc-prompt
                             front-sticky t
                             read-only t))))

      ;; Simulate some activity by inserting some text before and
      ;; after the prompt (multiline).
      (erc-display-error-notice nil "Welcome")
      (goto-char (point-max))
      (insert "Hello\nWorld")
      (goto-char 3)
      (should (looking-at-p (regexp-quote "*** Welcome"))))

    (ert-info ("Reconnect")
      (with-current-buffer (erc-server-buffer)
        (erc-open "localhost" 6667 "tester" "Tester" nil
                  "fake" nil "#chan" proc nil "user" nil))
      (should-not (get-buffer "#chan<2>")))

    (ert-info ("Existing prompt respected")
      (with-current-buffer (should (get-buffer "#chan"))
        (should (= ?\n (char-after 1)))
        (should (= ?E (char-after erc-insert-marker)))
        (should (= 15 (marker-position erc-insert-marker)))
        (should (= 20 (marker-position erc-input-marker)))
        (should (= 3 (point))) ; point restored
        (should (equal (buffer-string)
                       #("\n\n*** Welcome\nERC> Hello\nWorld"
                         2 13 (font-lock-face erc-error-face)
                         14 18 ( font-lock-face erc-prompt-face
                                 rear-nonsticky t
                                 erc-prompt t
                                 field erc-prompt
                                 front-sticky t
                                 read-only t)
                         18 19 ( rear-nonsticky t
                                 erc-prompt t
                                 field erc-prompt
                                 front-sticky t
                                 read-only t))))
        (when noninteractive
          (kill-buffer))))))

(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))
      (set-process-query-on-exit-flag erc-server-process nil)
      (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"))
      (set-process-query-on-exit-flag erc-server-process nil))

    (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-setup-buffer--custom-action ()
  (erc-mode)
  (erc-tests--set-fake-server-process "sleep" "1")
  (setq erc--server-last-reconnect-count 0)
  (let ((owin (selected-window))
        (obuf (window-buffer))
        (mbuf (messages-buffer))
        calls)
    (cl-letf (((symbol-function 'switch-to-buffer) ; regression
               (lambda (&rest r) (push (cons 'switch-to-buffer r) calls)))
              ((symbol-function 'erc--test-fun)
               (lambda (&rest r) (push (cons 'erc--test-fun r) calls)))
              ((symbol-function 'display-buffer)
               (lambda (&rest r) (push (cons 'display-buffer r) calls))))

      ;; Baseline
      (let ((erc-join-buffer 'bury))
        (erc-setup-buffer mbuf)
        (should-not calls))

      (should-not erc--display-context)

      ;; `display-buffer'
      (let ((erc--display-context '((erc-buffer-display . 1)))
            (erc-join-buffer 'erc--test-fun))
        (erc-setup-buffer mbuf)
        (should (equal `(erc--test-fun ,mbuf (nil (erc-buffer-display . 1)))
                       (pop calls)))
        (should-not calls))

      ;; `pop-to-buffer' with `erc-auto-reconnect-display'
      (let* ((erc--server-last-reconnect-count 1)
             (erc--display-context '((erc-buffer-display . 1)))
             (erc-auto-reconnect-display 'erc--test-fun))
        (erc-setup-buffer mbuf)
        (should (equal `(erc--test-fun ,mbuf
                                       (nil (erc-auto-reconnect-display . t)
                                            (erc-buffer-display . 1)))
                       (pop calls)))
        (should-not calls)))

    ;; Mimic simplistic version of example in "(erc) display-buffer".
    (when (>= emacs-major-version 29)
      (let ((proc erc-server-process))
        (with-temp-buffer
          (should-not (eq (window-buffer) (current-buffer)))
          (erc-mode)
          (setq erc-server-process proc)

          (cl-letf (((symbol-function 'erc--test-fun-p)
                     (lambda (buf action)
                       (should (eql 1 (alist-get 'erc-buffer-display action)))
                       (push (cons 'erc--test-fun-p buf) calls)))
                    ((symbol-function 'action-fn)
                     (lambda (buf action)
                       (should (eql 1 (alist-get 'erc-buffer-display action)))
                       (should (eql 42 (alist-get 'foo action)))
                       (push (cons 'action-fn buf) calls)
                       (selected-window))))

            (let ((erc--display-context '((erc-buffer-display . 1)))
                  (display-buffer-alist
                   `(((and (major-mode . erc-mode) erc--test-fun-p)
                      action-fn (foo . 42))))
                  (erc-buffer-display 'display-buffer))

              (erc-setup-buffer (current-buffer))
              (should (equal 'action-fn (car (pop calls))))
              (should (equal 'erc--test-fun-p (car (pop calls))))
              (should-not calls))))))

    (should (eq owin (selected-window)))
    (should (eq obuf (window-buffer)))))

(ert-deftest erc-lurker-maybe-trim ()
  (let (erc-lurker-trim-nicks
        (erc-lurker-ignore-chars "_`"))

    (should (string= "nick`" (erc-lurker-maybe-trim "nick`")))

    (setq erc-lurker-trim-nicks t)
    (should (string= "nick" (erc-lurker-maybe-trim "nick`")))
    (should (string= "ni`_ck" (erc-lurker-maybe-trim "ni`_ck__``")))

    (setq erc-lurker-ignore-chars "_-`") ; set of chars, not character alts
    (should (string= "nick" (erc-lurker-maybe-trim "nick-_`")))))

(ert-deftest erc-parse-user ()
  (should (equal erc--parse-user-regexp erc--parse-user-regexp-legacy))

  (should (equal '("" "" "") (erc-parse-user "!@")))
  (should (equal '("" "!" "") (erc-parse-user "!!@")))
  (should (equal '("" "" "@") (erc-parse-user "!@@")))
  (should (equal '("" "!" "@") (erc-parse-user "!!@@")))

  (should (equal '("abc" "" "") (erc-parse-user "abc")))
  (should (equal '("" "123" "fake") (erc-parse-user "!123@fake")))
  (should (equal '("abc" "" "123") (erc-parse-user "abc!123")))

  (should (equal '("abc" "123" "fake") (erc-parse-user "abc!123@fake")))
  (should (equal '("abc" "!123" "@xy") (erc-parse-user "abc!!123@@xy")))

  (should (equal '("de" "fg" "xy") (erc-parse-user "abc\nde!fg@xy")))

  (ert-info ("`erc--parse-user-regexp-pedantic'")
    (let ((erc--parse-user-regexp erc--parse-user-regexp-pedantic))
      (should (equal '("" "" "") (erc-parse-user "!@")))
      (should (equal '("" "!" "") (erc-parse-user "!!@")))
      (should (equal '("" "@" "") (erc-parse-user "!@@")))
      (should (equal '("" "!@" "") (erc-parse-user "!!@@")))

      (should (equal '("abc" "" "") (erc-parse-user "abc")))
      (should (equal '("" "123" "fake") (erc-parse-user "!123@fake")))
      (should (equal '("abc" "" "123") (erc-parse-user "abc!123")))

      (should (equal '("abc" "123" "fake") (erc-parse-user "abc!123@fake")))
      (should (equal '("abc" "!123@" "xy") (erc-parse-user "abc!!123@@xy")))

      (should (equal '("de" "" "fg@xy") (erc-parse-user "abc\nde!fg@xy"))))))

(ert-deftest erc--parse-isupport-value ()
  (should (equal (erc--parse-isupport-value "a,b") '("a" "b")))
  (should (equal (erc--parse-isupport-value "a,b,c") '("a" "b" "c")))

  (should (equal (erc--parse-isupport-value "abc") '("abc")))
  (should (equal (erc--parse-isupport-value "\\x20foo") '(" foo")))
  (should (equal (erc--parse-isupport-value "foo\\x20") '("foo ")))
  (should (equal (erc--parse-isupport-value "a\\x20b\\x20c") '("a b c")))
  (should (equal (erc--parse-isupport-value "a\\x20b\\x20c\\x20") '("a b c ")))
  (should (equal (erc--parse-isupport-value "\\x20a\\x20b\\x20c") '(" a b c")))
  (should (equal (erc--parse-isupport-value "a\\x20\\x20c") '("a  c")))
  (should (equal (erc--parse-isupport-value "\\x20\\x20\\x20") '("   ")))
  (should (equal (erc--parse-isupport-value "\\x5Co/") '("\\o/")))
  (should (equal (erc--parse-isupport-value "\\x7F,\\x19") '("\\x7F" "\\x19")))
  (should (equal (erc--parse-isupport-value "a\\x2Cb,c") '("a,b" "c"))))

(ert-deftest erc--get-isupport-entry ()
  (let ((erc--isupport-params (make-hash-table))
        (erc-server-parameters '(("FOO" . "1") ("BAR") ("BAZ" . "A,B,C")))
        (items (lambda ()
                 (cl-loop for k being the hash-keys of erc--isupport-params
                          using (hash-values v) collect (cons k v)))))

    (should-not (erc--get-isupport-entry 'FAKE))
    (should-not (erc--get-isupport-entry 'FAKE 'single))
    (should (zerop (hash-table-count erc--isupport-params)))

    (should (equal (erc--get-isupport-entry 'BAR) '(BAR)))
    (should-not (erc--get-isupport-entry 'BAR 'single))
    (should (= 1 (hash-table-count erc--isupport-params)))

    (should (equal (erc--get-isupport-entry 'BAZ) '(BAZ "A" "B" "C")))
    (should (equal (erc--get-isupport-entry 'BAZ 'single) "A"))
    (should (= 2 (hash-table-count erc--isupport-params)))

    (should (equal (erc--get-isupport-entry 'FOO 'single) "1"))
    (should (equal (erc--get-isupport-entry 'FOO) '(FOO "1")))

    (should (equal (funcall items)
                   '((BAR . --empty--) (BAZ "A" "B" "C") (FOO "1"))))))

(ert-deftest erc-server-005 ()
  (let* ((hooked 0)
         (verify #'ignore)
         (hook (lambda (_ _) (funcall verify) (cl-incf hooked)))
         (erc-server-005-functions (list #'erc-server-005 hook #'ignore))
         erc-server-parameters
         erc--isupport-params
         erc-timer-hook
         calls
         args
         parsed)

    (cl-letf (((symbol-function 'erc-display-message)
               (lambda (_ _ _ line) (push line calls))))

      (ert-info ("Baseline")
        (setq args '("tester" "BOT=B" "EXCEPTS" "PREFIX=(ov)@+" "are supp...")
              parsed (make-erc-response :command-args args :command "005"))

        (setq verify
              (lambda ()
                (should (equal erc-server-parameters
                               '(("PREFIX" . "(ov)@+") ("EXCEPTS")
                                 ("BOT" . "B"))))
                (should (zerop (hash-table-count erc--isupport-params)))
                (should (equal "(ov)@+" (erc--get-isupport-entry 'PREFIX t)))
                (should (equal '(EXCEPTS) (erc--get-isupport-entry 'EXCEPTS)))
                (should (equal "B" (erc--get-isupport-entry 'BOT t)))
                (should (string= (pop calls)
                                 "BOT=B EXCEPTS PREFIX=(ov)@+ are supp..."))
                (should (equal args (erc-response.command-args parsed)))))

        (erc-call-hooks nil parsed))

      (ert-info ("Negated, updated")
        (setq args '("tester" "-EXCEPTS" "-FAKE" "PREFIX=(ohv)@%+" "are su...")
              parsed (make-erc-response :command-args args :command "005"))

        (setq verify
              (lambda ()
                (should (equal erc-server-parameters
                               '(("PREFIX" . "(ohv)@%+") ("BOT" . "B"))))
                (should (string= (pop calls)
                                 "-EXCEPTS -FAKE PREFIX=(ohv)@%+ are su..."))
                (should (equal "(ohv)@%+" (erc--get-isupport-entry 'PREFIX t)))
                (should (equal "B" (erc--get-isupport-entry 'BOT t)))
                (should-not (erc--get-isupport-entry 'EXCEPTS))
                (should (equal args (erc-response.command-args parsed)))))

        (erc-call-hooks nil parsed))
      (should (= hooked 2)))))

(ert-deftest erc-downcase ()
  (let ((erc--isupport-params (make-hash-table)))

    (puthash 'PREFIX '("(ov)@+") erc--isupport-params)
    (puthash 'BOT '("B") erc--isupport-params)

    (ert-info ("ascii")
      (puthash 'CASEMAPPING  '("ascii") erc--isupport-params)
      (should (equal (erc-downcase "ABC 123 ΔΞΩΣ") "abc 123 ΔΞΩΣ"))
      (should (equal (erc-downcase "Bob[m]`") "bob[m]`"))
      (should (equal (erc-downcase "Tilde~") "tilde~" ))
      (should (equal (erc-downcase "\\O/") "\\o/" )))

    (ert-info ("rfc1459")
      (puthash 'CASEMAPPING  '("rfc1459") erc--isupport-params)
      (should (equal (erc-downcase "ABC 123 ΔΞΩΣ") "abc 123 ΔΞΩΣ"))
      (should (equal (erc-downcase "Bob[m]`") "bob{m}`" ))
      (should (equal (erc-downcase "Tilde~") "tilde^" ))
      (should (equal (erc-downcase "\\O/") "|o/" )))

    (ert-info ("rfc1459-strict")
      (puthash 'CASEMAPPING  '("rfc1459-strict") erc--isupport-params)
      (should (equal (erc-downcase "ABC 123 ΔΞΩΣ") "abc 123 ΔΞΩΣ"))
      (should (equal (erc-downcase "Bob[m]`") "bob{m}`"))
      (should (equal (erc-downcase "Tilde~") "tilde~" ))
      (should (equal (erc-downcase "\\O/") "|o/" )))))

(ert-deftest erc-channel-p ()
  (let ((erc--isupport-params (make-hash-table))
        erc-server-parameters)

    (should (erc-channel-p "#chan"))
    (should (erc-channel-p "##chan"))
    (should (erc-channel-p "&chan"))
    (should (erc-channel-p "+chan"))
    (should (erc-channel-p "!chan"))
    (should-not (erc-channel-p "@chan"))

    (push '("CHANTYPES" . "#&@+!") erc-server-parameters)

    (should (erc-channel-p "!chan"))
    (should (erc-channel-p "#chan"))

    (with-current-buffer (get-buffer-create "#chan")
      (setq erc--target (erc--target-from-string "#chan")))
    (should (erc-channel-p (get-buffer "#chan"))))
  (kill-buffer "#chan"))

(ert-deftest erc--valid-local-channel-p ()
  (ert-info ("Local channels not supported")
    (let ((erc--isupport-params (make-hash-table)))
      (puthash 'CHANTYPES  '("#") erc--isupport-params)
      (should-not (erc--valid-local-channel-p "#chan"))
      (should-not (erc--valid-local-channel-p "&local"))))
  (ert-info ("Local channels supported")
    (let ((erc--isupport-params (make-hash-table)))
      (puthash 'CHANTYPES  '("&#") erc--isupport-params)
      (should-not (erc--valid-local-channel-p "#chan"))
      (should (erc--valid-local-channel-p "&local")))))

(ert-deftest erc--restore-initialize-priors ()
  (should (pcase (macroexpand-1 '(erc--restore-initialize-priors erc-my-mode
                                   foo (ignore 1 2 3)
                                   bar #'spam
                                   baz nil))
            (`(let* ((,p (or erc--server-reconnecting erc--target-priors))
                     (,q (and ,p (alist-get 'erc-my-mode ,p))))
                (setq foo (if ,q (alist-get 'foo ,p) (ignore 1 2 3))
                      bar (if ,q (alist-get 'bar ,p) #'spam)
                      baz (if ,q (alist-get 'baz ,p) nil)))
             t))))

(ert-deftest erc--target-from-string ()
  (should (equal (erc--target-from-string "#chan")
                 #s(erc--target-channel "#chan" \#chan nil)))

  (should (equal (erc--target-from-string "Bob")
                 #s(erc--target "Bob" bob)))

  (let ((erc--isupport-params (make-hash-table)))
    (puthash 'CHANTYPES  '("&#") erc--isupport-params)
    (should (equal (erc--target-from-string "&Bitlbee")
                   #s(erc--target-channel-local "&Bitlbee" &bitlbee nil)))))

(ert-deftest erc--modify-local-map ()
  (when (and (bound-and-true-p erc-irccontrols-mode)
             (fboundp 'erc-irccontrols-mode))
    (erc-irccontrols-mode -1))
  (when (and (bound-and-true-p erc-match-mode)
             (fboundp 'erc-match-mode))
    (erc-match-mode -1))
  (let* (calls
         (inhibit-message noninteractive)
         (cmd-foo (lambda () (interactive) (push 'foo calls)))
         (cmd-bar (lambda () (interactive) (push 'bar calls))))

    (ert-info ("Add non-existing")
      (erc--modify-local-map t "C-c C-c" cmd-foo "C-c C-k" cmd-bar)
      (with-temp-buffer
        (set-window-buffer (selected-window) (current-buffer))
        (use-local-map erc-mode-map)
        (execute-kbd-macro "\C-c\C-c")
        (execute-kbd-macro "\C-c\C-k"))
      (should (equal calls '(bar foo))))
    (setq calls nil)

    (ert-info ("Add existing") ; Attempt to swap definitions fails
      (erc--modify-local-map t "C-c C-c" cmd-bar "C-c C-k" cmd-foo)
      (with-temp-buffer
        (set-window-buffer (selected-window) (current-buffer))
        (use-local-map erc-mode-map)
        (execute-kbd-macro "\C-c\C-c")
        (execute-kbd-macro "\C-c\C-k"))
      (should (equal calls '(bar foo))))
    (setq calls nil)

    (ert-info ("Remove existing")
      (ert-with-message-capture messages
        (erc--modify-local-map nil "C-c C-c" cmd-foo "C-c C-k" cmd-bar)
        (with-temp-buffer
          (set-window-buffer (selected-window) (current-buffer))
          (use-local-map erc-mode-map)
          (execute-kbd-macro "\C-c\C-c")
          (execute-kbd-macro "\C-c\C-k"))
        (should (string-search "C-c C-c is undefined" messages))
        (should (string-search "C-c C-k is undefined" messages))
        (should-not calls)))))

(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)
    (erc-tests--send-prep)
    (setq erc-server-current-nick "tester")
    (setq-local erc-last-input-time 0)
    (should-not (local-variable-if-set-p 'erc-send-completed-hook))
    (set (make-local-variable 'erc-send-completed-hook) nil) ; skip t (globals)
    ;; Just in case erc-ring-mode is already on
    (setq-local erc--input-review-functions erc--input-review-functions)
    (add-hook 'erc--input-review-functions #'erc-add-to-input-ring)
    ;;
    (cl-letf (((symbol-function 'erc-process-input-line)
               (lambda (&rest _)
                 (erc-display-message
                  nil 'notice (current-buffer) "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)
                                (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*")))

(ert-deftest erc--debug-irc-protocol-mask-secrets ()
  (should-not erc-debug-irc-protocol)
  (should erc--debug-irc-protocol-mask-secrets)
  (with-temp-buffer
    (setq erc-server-process (start-process "fake" (current-buffer) "true")
          erc-server-current-nick "tester"
          erc-session-server "myproxy.localhost"
          erc-session-port 6667)
    (let ((inhibit-message noninteractive))
      (erc-toggle-debug-irc-protocol)
      (erc-log-irc-protocol
       (concat "PASS :" (erc--unfun (lambda () "changeme")) "\r\n")
       'outgoing)
      (set-process-query-on-exit-flag erc-server-process nil))
    (with-current-buffer "*erc-protocol*"
      (goto-char (point-min))
      (search-forward "\r\n\r\n")
      (search-forward "myproxy.localhost:6667 >> PASS :????????" (pos-eol)))
    (when noninteractive
      (kill-buffer "*erc-protocol*")
      (should-not erc-debug-irc-protocol))))

(ert-deftest erc-log-irc-protocol ()
  (should-not erc-debug-irc-protocol)
  (with-temp-buffer
    (setq erc-server-process (start-process "fake" (current-buffer) "true")
          erc-server-current-nick "tester"
          erc-session-server "myproxy.localhost"
          erc-session-port 6667)
    (let ((inhibit-message noninteractive))
      (erc-toggle-debug-irc-protocol)
      (erc-log-irc-protocol "PASS changeme\r\n" 'outgoing)
      (setq erc-server-announced-name "irc.gnu.org")
      (erc-log-irc-protocol ":irc.gnu.org 001 tester :Welcome")
      (erc-log-irc-protocol ":irc.gnu.org 002 tester :Your host is irc.gnu.org")
      (setq erc-network 'FooNet)
      (setq erc-networks--id (erc-networks--id-create nil))
      (erc-log-irc-protocol ":irc.gnu.org 422 tester :MOTD missing")
      (setq erc-networks--id (erc-networks--id-create 'BarNet))
      (erc-log-irc-protocol ":irc.gnu.org 221 tester +i")
      (set-process-query-on-exit-flag erc-server-process nil)))
  (with-current-buffer "*erc-protocol*"
    (goto-char (point-min))
    (search-forward "Version")
    (search-forward "\r\n\r\n")
    (search-forward "myproxy.localhost:6667 >> PASS" (pos-eol))
    (forward-line)
    (search-forward "irc.gnu.org << :irc.gnu.org 001" (pos-eol))
    (forward-line)
    (search-forward "irc.gnu.org << :irc.gnu.org 002" (pos-eol))
    (forward-line)
    (search-forward "FooNet << :irc.gnu.org 422" (pos-eol))
    (forward-line)
    (search-forward "BarNet << :irc.gnu.org 221" (pos-eol)))
  (when noninteractive
    (kill-buffer "*erc-protocol*")
    (should-not erc-debug-irc-protocol)))

(ert-deftest erc--split-line ()
  (let ((erc-default-recipients '("#chan"))
        (erc-split-line-length 10))
    (should (equal (erc--split-line "") '("")))
    (should (equal (erc--split-line "0123456789") '("0123456789")))
    (should (equal (erc--split-line "0123456789a") '("0123456789" "a")))

    (should (equal (erc--split-line "0123456789 ") '("0123456789" " ")))
    (should (equal (erc--split-line "01234567 89") '("01234567 " "89")))
    (should (equal (erc--split-line "0123456 789") '("0123456 " "789")))
    (should (equal (erc--split-line "0 123456789") '("0 " "123456789")))
    (should (equal (erc--split-line " 0123456789") '(" " "0123456789")))
    (should (equal (erc--split-line "012345678 9a") '("012345678 " "9a")))
    (should (equal (erc--split-line "0123456789 a") '("0123456789" " a")))

    ;; UTF-8 vs. KOI-8
    (should (= 10 (string-bytes "Русск"))) ; utf-8
    (should (equal (erc--split-line "Русск") '("Русск")))
    (should (equal (erc--split-line "РусскийТекст") '("Русск" "ийТек" "ст")))
    (should (equal (erc--split-line "Русский Текст") '("Русск" "ий " "Текст")))
    (let ((erc-encoding-coding-alist '(("#chan" . cyrillic-koi8))))
      (should (equal (erc--split-line "Русск") '("Русск")))
      (should (equal (erc--split-line "РусскийТекст") '("РусскийТек" "ст")))
      (should (equal (erc--split-line "Русский Текст") '("Русский " "Текст"))))

    ;; UTF-8 vs. Latin 1
    (should (= 17 (string-bytes "Hyvää päivää")))
    (should (equal (erc--split-line "Hyvää päivää") '("Hyvää " "päivää")))
    (should (equal (erc--split-line "HyvääPäivää") '("HyvääPä" "ivää")))
    (let ((erc-encoding-coding-alist '(("#chan" . latin-1))))
      (should (equal (erc--split-line "Hyvää päivää") '("Hyvää " "päivää")))
      (should (equal (erc--split-line "HyvääPäivää") '("HyvääPäivä" "ä"))))

    ;; Combining characters
    (should (= 10 (string-bytes "Åström")))
    (should (equal (erc--split-line "_Åström") '("_Åströ" "m")))
    (should (equal (erc--split-line "__Åström") '("__Åstr" "öm")))
    (should (equal (erc--split-line "___Åström") '("___Åstr" "öm")))
    (when (> emacs-major-version 27)
      (should (equal (erc--split-line "🏁🚩🎌🏴🏳️🏳️‍🌈🏳️‍⚧️🏴‍☠️")
                     '("🏁🚩" "🎌🏴" "🏳️" "🏳️‍🌈" "🏳️‍⚧️" "🏴‍☠️"))))))

(ert-deftest erc--input-line-delim-regexp ()
  (let ((p erc--input-line-delim-regexp))
    ;; none
    (should (equal '("a" "b") (split-string "a\r\nb" p)))
    (should (equal '("a" "b") (split-string "a\nb" p)))
    (should (equal '("a" "b") (split-string "a\rb" p)))

    ;; one
    (should (equal '("") (split-string "" p)))
    (should (equal '("a" "" "b") (split-string "a\r\rb" p)))
    (should (equal '("a" "" "b") (split-string "a\n\rb" p)))
    (should (equal '("a" "" "b") (split-string "a\n\nb" p)))
    (should (equal '("a" "" "b") (split-string "a\r\r\nb" p)))
    (should (equal '("a" "" "b") (split-string "a\n\r\nb" p)))
    (should (equal '("a" "") (split-string "a\n" p)))
    (should (equal '("a" "") (split-string "a\r" p)))
    (should (equal '("a" "") (split-string "a\r\n" p)))
    (should (equal '("" "b") (split-string "\nb" p)))
    (should (equal '("" "b") (split-string "\rb" p)))
    (should (equal '("" "b") (split-string "\r\nb" p)))

    ;; two
    (should (equal '("" "") (split-string "\r" p)))
    (should (equal '("" "") (split-string "\n" p)))
    (should (equal '("" "") (split-string "\r\n" p)))

    ;; three
    (should (equal '("" "" "") (split-string "\r\r" p)))
    (should (equal '("" "" "") (split-string "\n\n" p)))
    (should (equal '("" "" "") (split-string "\n\r" p)))))

(defun erc-tests--with-process-input-spy (test)
  (with-current-buffer (get-buffer-create "FakeNet")
    (let* ((erc--input-review-functions
            (remove #'erc-add-to-input-ring erc--input-review-functions))
           (erc-pre-send-functions
            (remove #'erc-add-to-input-ring erc-pre-send-functions)) ; for now
           (inhibit-message noninteractive)
           (erc-server-current-nick "tester")
           (erc-last-input-time 0)
           erc-accidental-paste-threshold-seconds
           erc-send-modify-hook
           ;;
           calls)
      (cl-letf (((symbol-function 'erc-process-input-line)
                 (lambda (&rest r) (push r calls)))
                ((symbol-function 'erc-server-buffer)
                 (lambda () (current-buffer))))
        (erc-tests--send-prep)
        (funcall test (lambda () (pop calls)))))
    (when noninteractive (kill-buffer))))

(ert-deftest erc--check-prompt-input-functions ()
  (erc-tests--with-process-input-spy
   (lambda (next)

     (ert-info ("Errors when point not in prompt area") ; actually just dings
       (insert "/msg #chan hi")
       (forward-line -1)
       (let ((e (should-error (erc-send-current-line))))
         (should (equal "Point is not in the input area" (cadr e))))
       (goto-char (point-max))
       (ert-info ("Input remains untouched")
         (should (save-excursion (erc-bol) (looking-at "/msg #chan hi")))))

     (ert-info ("Errors when no process running")
       (let ((e (should-error (erc-send-current-line))))
         (should (equal "ERC: No process running" (cadr e))))
       (ert-info ("Input remains untouched")
         (should (save-excursion (erc-bol) (looking-at "/msg #chan hi")))))

     (ert-info ("Errors when line contains empty newline")
       (erc-bol)
       (delete-region (point) (point-max))
       (insert "one\n")
       (let ((e (should-error (erc-send-current-line))))
         (should (string-prefix-p "Trailing line detected" (cadr e))))
       (goto-char (point-max))
       (ert-info ("Input remains untouched")
         (should (save-excursion (goto-char erc-input-marker)
                                 (looking-at "one\n")))))

     (should (= 0 erc-last-input-time))
     (should-not (funcall next)))))

;; These also indirectly tests `erc-send-input'

(ert-deftest erc-send-current-line ()
  (erc-tests--with-process-input-spy
   (lambda (next)
     (erc-tests--set-fake-server-process "sleep" "1")
     (should (= 0 erc-last-input-time))

     (ert-info ("Simple command")
       (insert "/msg #chan hi")
       (erc-send-current-line)
       (ert-info ("Prompt restored")
         (forward-line 0)
         (should (looking-at-p erc-prompt)))
       (ert-info ("Input cleared")
         (erc-bol)
         (should (eq (point) (point-max))))
       ;; The `force' argument is irrelevant here because it can't
       ;; influence dispatched handlers, such as `erc-cmd-MSG'.
       (should (pcase (funcall next) (`("/msg #chan hi\n" ,_ nil) t))))

     (ert-info ("Simple non-command")
       (insert "hi")
       (erc-send-current-line)
       (should (eq (point) (point-max)))
       (should (save-excursion (forward-line -1)
                               (search-forward "<tester> hi")))
       ;; Non-commands are forced only when `erc-flood-protect' is
       ;; nil, which conflates two orthogonal concerns.
       (should (equal (funcall next) '("hi\n" nil t))))

     (should (consp erc-last-input-time)))))

(ert-deftest erc--discard-trailing-multiline-nulls ()
  (pcase-dolist (`(,input ,want) '((("") (""))
                                   (("" "") (""))
                                   (("a") ("a"))
                                   (("a" "") ("a"))
                                   (("" "a") ("" "a"))
                                   (("" "a" "") ("" "a"))))
    (ert-info ((format "Input: %S, want: %S" input want))
      (let ((s (make-erc--input-split :lines input)))
        (erc--discard-trailing-multiline-nulls s)
        (should (equal (erc--input-split-lines s) want))))))

(ert-deftest erc--count-blank-lines ()
  (pcase-dolist (`(,input ,want) '((() (0 0 0))
                                   (("") (1 1 0))
                                   (("" "") (2 1 1))
                                   (("" "" "") (3 1 2))
                                   ((" " "") (2 0 1))
                                   ((" " "" "") (3 0 2))
                                   (("" " " "") (3 1 1))
                                   (("" "" " ") (3 2 0))
                                   (("a") (0 0 0))
                                   (("a" "") (1 0 1))
                                   (("a" " " "") (2 0 1))
                                   (("a" "" "") (2 0 2))
                                   (("a" "b") (0 0 0))
                                   (("a" "" "b") (1 1 0))
                                   (("a" " " "b") (1 0 0))
                                   (("" "a") (1 1 0))
                                   ((" " "a") (1 0 0))
                                   (("" "a" "") (2 1 1))
                                   (("" " " "a" "" " ") (4 2 0))
                                   (("" " " "a" "" " " "") (5 2 1))))
    (ert-info ((format "Input: %S, want: %S" input want))
      (should (equal (erc--count-blank-lines input) want)))))

;; Opt `wb': `erc-warn-about-blank-lines'
;; Opt `sw': `erc-send-whitespace-lines'
;; `s': " \n",`a': "a\n",`b': "b\n"
(defvar erc-tests--check-prompt-input--expect
  ;;  opts     ""  " "   "\n"  "\n "   " \n" "\n\n" "a\n" "a\n " "a\n \nb"
  '(((+wb -sw) err err   err   err     err   err    err   err    err)
    ((-wb -sw) nop nop   nop   nop     nop   nop    nop   nop    nop)
    ((+wb +sw) err (s)   (0 s) (1 s s) (s)   (0 s)  (0 a) (a s)  (a s b))
    ((-wb +sw) nop (s)   (s)   (s s)   (s)   (s)    (a)   (a s)  (a s b))))

;; Help messages echoed (not IRC message) was emitted
(defvar erc-tests--check-prompt-input-messages
  '("Stripping" "Padding"))

(ert-deftest erc--check-prompt-input-for-multiline-blanks ()
  (erc-tests--with-process-input-spy
   (lambda (next)
     (erc-tests--set-fake-server-process "sleep" "1")
     (should-not erc-send-whitespace-lines)
     (should erc-warn-about-blank-lines)

     (pcase-dolist (`((,wb ,sw) . ,ex) erc-tests--check-prompt-input--expect)
       (let ((print-escape-newlines t)
             (erc-warn-about-blank-lines (eq wb '+wb))
             (erc-send-whitespace-lines (eq sw '+sw))
             (samples '("" " " "\n" "\n " " \n" "\n\n"
                        "a\n" "a\n " "a\n \nb")))
         (setq ex `(,@ex (a) (a b)) ; baseline, same for all combos
               samples `(,@samples "a" "a\nb"))
         (dolist (input samples)
           (insert input)
           (ert-info ((format "Opts: %S, Input: %S, want: %S"
                              (list wb sw) input (car ex)))
             (ert-with-message-capture messages
               (pcase-exhaustive (pop ex)
                 ('err (let ((e (should-error (erc-send-current-line))))
                         (should (string-match (rx (| "trailing" "blank"))
                                               (cadr e))))
                       (should (equal (erc-user-input) input))
                       (should-not (funcall next)))
                 ('nop (erc-send-current-line)
                       (should (equal (erc-user-input) input))
                       (should-not (funcall next)))
                 ('clr (erc-send-current-line)
                       (should (string-empty-p (erc-user-input)))
                       (should-not (funcall next)))
                 ((and (pred consp) v)
                  (erc-send-current-line)
                  (should (string-empty-p (erc-user-input)))
                  (setq v (reverse v)) ; don't use `nreverse' here
                  (while v
                    (pcase (pop v)
                      ((and (pred integerp) n)
                       (should (string-search
                                (nth n erc-tests--check-prompt-input-messages)
                                messages)))
                      ('s (should (equal " \n" (car (funcall next)))))
                      ('a (should (equal "a\n" (car (funcall next)))))
                      ('b (should (equal "b\n" (car (funcall next)))))))
                  (should-not (funcall next))))))
           (delete-region erc-input-marker (point-max))))))))

(ert-deftest erc--check-prompt-input-for-multiline-blanks/explanations ()
  (should erc-warn-about-blank-lines)
  (should-not erc-send-whitespace-lines)

  (let ((erc-send-whitespace-lines t))
    (pcase-dolist (`(,input ,msg)
                   '((("") "Padding (1) blank line")
                     (("" " ") "Padding (1) blank line")
                     ((" " "") "Stripping (1) blank line")
                     (("a" "") "Stripping (1) blank line")
                     (("" "") "Stripping (1) and padding (1) blank lines")
                     (("" "" "") "Stripping (2) and padding (1) blank lines")
                     (("" "a" "" "b" "" "c" "" "")
                      "Stripping (2) and padding (3) blank lines")))
      (ert-info ((format "Input: %S, Msg: %S" input msg))
        (let (erc--check-prompt-explanation)
          (should-not (erc--check-prompt-input-for-multiline-blanks nil input))
          (should (equal (list msg) erc--check-prompt-explanation))))))

  (pcase-dolist (`(,input ,msg)
                 '((("") "Blank line detected")
                   (("" " ") "2 blank lines detected")
                   ((" " "") "2 blank (1 trailing) lines detected")
                   (("a" "") "Trailing line detected")
                   (("" "") "2 blank (1 trailing) lines detected")
                   (("a" "" "") "2 trailing lines detected")
                   (("" "a" "" "b" "" "c" "" "")
                    "5 blank (2 trailing) lines detected")))
    (ert-info ((format "Input: %S, Msg: %S" input msg))
      (let ((rv (erc--check-prompt-input-for-multiline-blanks nil input)))
        (should (equal (concat msg " (see `erc-send-whitespace-lines')")
                       rv ))))))

(ert-deftest erc-send-whitespace-lines ()
  (erc-tests--with-process-input-spy
   (lambda (next)
     (erc-tests--set-fake-server-process "sleep" "1")
     (setq-local erc-send-whitespace-lines t)

     (ert-info ("Multiline hunk with blank line correctly split")
       (insert "one\n\ntwo")
       (erc-send-current-line)
       (ert-info ("Prompt restored")
         (forward-line 0)
         (should (looking-at-p erc-prompt)))
       (ert-info ("Input cleared")
         (erc-bol)
         (should (eq (point) (point-max))))
       (should (equal (funcall next) '("two\n" nil t)))
       (should (equal (funcall next) '(" \n" nil t)))
       (should (equal (funcall next) '("one\n" nil t))))

     (ert-info ("Multiline hunk with trailing newline filtered")
       (insert "hi\n")
       (erc-send-current-line)
       (ert-info ("Input cleared")
         (erc-bol)
         (should (eq (point) (point-max))))
       (should (equal (funcall next) '("hi\n" nil t)))
       (should-not (funcall next)))

     (ert-info ("Multiline hunk with trailing carriage filtered")
       (insert "hi\r")
       (erc-send-current-line)
       (ert-info ("Input cleared")
         (erc-bol)
         (should (eq (point) (point-max))))
       (should (equal (funcall next) '("hi\n" nil t)))
       (should-not (funcall next)))

     (ert-info ("Multiline command with trailing blank filtered")
       (dolist (p '("/a b" "/a b\n" "/a b\n\n" "/a b\n\n\n"))
         (insert p)
         (erc-send-current-line)
         (erc-bol)
         (should (eq (point) (point-max)))
         (should (pcase (funcall next) (`(,cmd ,_ nil) (equal cmd "/a b\n"))))
         (should-not (funcall next))))

     (ert-info ("Multiline command with non-blanks errors")
       (dolist (p '("/a b\nc\n\n" "/a b\n/c\n\n" "/a b\n\nc\n\n"
                    "/a\n c\n" "/a\nb\n" "/a\n/b\n" "/a \n \n"))
         (insert p)
         (should-error (erc-send-current-line))
         (goto-char erc-input-marker)
         (delete-region (point) (point-max))
         (should-not (funcall next))))

     (ert-info ("Multiline hunk with trailing whitespace not filtered")
       (insert "there\n ")
       (erc-send-current-line)
       (should (equal (funcall next) '(" \n" nil t)))
       (should (equal (funcall next) '("there\n" nil t)))
       (should-not (funcall next))))))

(ert-deftest erc--check-prompt-input-for-excess-lines ()
  (ert-info ("Without `erc-inhibit-multiline-input'")
    (should-not erc-inhibit-multiline-input)
    (should-not (erc--check-prompt-input-for-excess-lines "" '("a" "b"))))

  (ert-info ("With `erc-inhibit-multiline-input' as t (2)")
    (let ((erc-inhibit-multiline-input t))
      (should-not (erc--check-prompt-input-for-excess-lines "" '("a")))
      ;; Does not trim trailing blanks.
      (should (erc--check-prompt-input-for-excess-lines "" '("a" "")))
      (should (erc--check-prompt-input-for-excess-lines "" '("a" "b")))))

  (ert-info ("With `erc-inhibit-multiline-input' as 3")
    (let ((erc-inhibit-multiline-input 3))
      (should-not (erc--check-prompt-input-for-excess-lines "" '("a" "b")))
      (should (erc--check-prompt-input-for-excess-lines "" '("a" "b" "")))
      (should (erc--check-prompt-input-for-excess-lines "" '("a" "b" "c")))))

  (ert-info ("With `erc-ask-about-multiline-input'")
    (let ((erc-inhibit-multiline-input t)
          (erc-ask-about-multiline-input t))
      (ert-simulate-keys '(?n ?\r ?y ?\r)
        (should (erc--check-prompt-input-for-excess-lines "" '("a" "b")))
        (should-not (erc--check-prompt-input-for-excess-lines "" '("a" "b")))))
    (should-not erc-ask-about-multiline-input)))

;; The point of this test is to ensure output is handled identically
;; regardless of whether a command handler is summoned.

(ert-deftest erc-process-input-line ()
  (let (erc-server-last-sent-time
        erc-server-flood-queue
        (orig-erc-cmd-MSG (symbol-function 'erc-cmd-MSG))
        (erc-default-recipients '("#chan"))
        calls)
    (with-temp-buffer
      (erc-tests--set-fake-server-process "sleep" "1")
      (cl-letf (((symbol-function 'erc-cmd-MSG)
                 (lambda (line)
                   (push line calls)
                   (should erc--called-as-input-p)
                   (funcall orig-erc-cmd-MSG line)))
                ((symbol-function 'erc-server-send-queue)
                 #'ignore))

        (ert-info ("Dispatch to user command handler")

          (ert-info ("Baseline")
            (erc-process-input-line "/msg #chan hi\n")
            (should (equal (pop calls) " #chan hi"))
            (should (equal (pop erc-server-flood-queue)
                           '("PRIVMSG #chan :hi\r\n" . utf-8))))

          (ert-info ("Quote preserves line intact")
            (erc-process-input-line "/QUOTE FAKE foo bar\n")
            (should (equal (pop erc-server-flood-queue)
                           '("FAKE foo bar\r\n" . utf-8))))

          (ert-info ("Unknown command respected")
            (erc-process-input-line "/FAKE foo bar\n")
            (should (equal (pop erc-server-flood-queue)
                           '("FAKE foo bar\r\n" . utf-8))))

          (ert-info ("Spaces preserved")
            (erc-process-input-line "/msg #chan hi you\n")
            (should (equal (pop calls) " #chan hi you"))
            (should (equal (pop erc-server-flood-queue)
                           '("PRIVMSG #chan :hi you\r\n" . utf-8))))

          (ert-info ("Empty line honored")
            (erc-process-input-line "/msg #chan\n")
            (should (equal (pop calls) " #chan"))
            (should (equal (pop erc-server-flood-queue)
                           '("PRIVMSG #chan :\r\n" . utf-8)))))

        (ert-info ("Implicit cmd via `erc-send-input-line-function'")

          (ert-info ("Baseline")
            (erc-process-input-line "hi\n")
            (should (equal (pop erc-server-flood-queue)
                           '("PRIVMSG #chan :hi\r\n" . utf-8))))

          (ert-info ("Spaces preserved")
            (erc-process-input-line "hi you\n")
            (should (equal (pop erc-server-flood-queue)
                           '("PRIVMSG #chan :hi you\r\n" . utf-8))))

          (ert-info ("Empty line transmitted with injected-space kludge")
            (erc-process-input-line "\n")
            (should (equal (pop erc-server-flood-queue)
                           '("PRIVMSG #chan : \r\n" . utf-8))))

          (should-not calls))))))

(ert-deftest erc--get-inserted-msg-bounds ()
  (erc-mode)
  (erc--initialize-markers (point) nil)
  (let ((parsed (make-erc-response :unparsed ":bob PRIVMSG #chan :hi"
                                   :sender "bob"
                                   :command "PRIVMSG"
                                   :command-args (list "#chan" "hi")
                                   :contents "hi"))
        (erc--msg-prop-overrides '((erc-ts . 0))))
    (erc-display-message parsed nil (current-buffer)
                         (erc-format-privmessage "bob" "hi" nil t)))
  (goto-char 3)
  (should (looking-at "<bob> hi"))
  (goto-char 11)
  (should (looking-back "<bob> hi"))

  (ert-info ("Parameter `only' being `beg'")
    (dolist (i (number-sequence 3 11))
      (goto-char i)
      (ert-info ((format "At %d (%c)" i (char-after i)))
        (should (= 3 (erc--get-inserted-msg-bounds 'beg)))))

    (ert-info ("Parameter `point'")
      (dolist (i (number-sequence 3 11))
        (ert-info ((format "At %d (%c)" i (char-after i)))
          (should (= 3 (erc--get-inserted-msg-bounds 'beg i)))))))

  (ert-info ("Parameter `only' being `end'")
    (dolist (i (number-sequence 3 11))
      (goto-char i)
      (ert-info ((format "At %d (%c)" i (char-after i)))
        (should (= 11 (erc--get-inserted-msg-bounds 'end)))))

    (ert-info ("Parameter `point'")
      (dolist (i (number-sequence 3 11))
        (ert-info ((format "At %d (%c)" i (char-after i)))
          (should (= 11 (erc--get-inserted-msg-bounds 'end i)))))))

  (ert-info ("Parameter `only' being nil")
    (dolist (i (number-sequence 3 11))
      (goto-char i)
      (ert-info ((format "At %d (%c)" i (char-after i)))
        (should (equal '(3 . 11) (erc--get-inserted-msg-bounds nil)))))

    (ert-info ("Parameter `point'")
      (dolist (i (number-sequence 3 11))
        (ert-info ((format "At %d (%c)" i (char-after i)))
          (should (equal '(3 . 11) (erc--get-inserted-msg-bounds nil i))))))))

(ert-deftest erc--delete-inserted-message ()
  (erc-mode)
  (erc--initialize-markers (point) nil)
  ;; Put unique invisible properties on the line endings.
  (erc-display-message nil 'notice nil "one")
  (put-text-property (1- erc-insert-marker) erc-insert-marker 'invisible 'a)
  (let ((erc--msg-prop-overrides '((erc-msg . datestamp) (erc-ts . 0))))
    (erc-display-message nil nil nil
                         (propertize "\n[date]" 'field 'erc-timestamp)))
  (put-text-property (1- erc-insert-marker) erc-insert-marker 'invisible 'b)
  (erc-display-message nil 'notice nil "two")

  (ert-info ("Date stamp deleted cleanly")
    (goto-char 11)
    (should (looking-at (rx "\n[date]")))
    (should (eq 'datestamp (get-text-property (point) 'erc-msg)))
    (should (eq (point) (field-beginning (1+ (point)))))

    (erc--delete-inserted-message (point))

    ;; Preceding line ending clobbered, replaced by trailing.
    (should (looking-back (rx "*** one\n")))
    (should (looking-at (rx "*** two")))
    (should (eq 'b (get-text-property (1- (point)) 'invisible))))

  (ert-info ("Markers at pos-bol preserved")
    (erc-display-message nil 'notice nil "three")
    (should (looking-at (rx "*** two")))

    (let ((m (point-marker))
          (n (point-marker))
          (p (point)))
      (set-marker-insertion-type m t)
      (goto-char (point-max))
      (erc--delete-inserted-message p)
      (should (= (marker-position n) p))
      (should (= (marker-position m) p))
      (goto-char p)
      (set-marker m nil)
      (set-marker n nil)
      (should (looking-back (rx "*** one\n")))
      (should (looking-at (rx "*** three")))))

  (ert-info ("Compat")
    (erc-display-message nil 'notice nil "four")
    (should (looking-at (rx "*** three\n")))
    (with-suppressed-warnings ((obsolete erc-legacy-invisible-bounds-p))
      (let ((erc-legacy-invisible-bounds-p t))
        (erc--delete-inserted-message (point))))
    (should (looking-at (rx "*** four\n"))))

  (ert-info ("Deleting most recent message preserves markers")
    (let ((m (point-marker))
          (n (point-marker))
          (p (point)))
      (should (equal "*** four\n" (buffer-substring p erc-insert-marker)))
      (set-marker-insertion-type m t)
      (goto-char (point-max))
      (erc--delete-inserted-message p)
      (should (= (marker-position m) p))
      (should (= (marker-position n) p))
      (goto-char p)
      (should (looking-back (rx "*** one\n")))
      (should (looking-at erc-prompt))
      (erc--assert-input-bounds)

      ;; However, `m' is now forever "trapped" at `erc-insert-marker'.
      (erc-display-message nil 'notice nil "two")
      (should (= m erc-insert-marker))
      (goto-char n)
      (should (looking-at (rx "*** two\n")))
      (set-marker m nil)
      (set-marker n nil))))

(ert-deftest erc--order-text-properties-from-hash ()
  (let ((table (map-into '((a . 1)
                           (erc-ts . 0)
                           (erc-msg . s005)
                           (b . 2)
                           (erc-cmd . 5)
                           (c . 3))
                         'hash-table)))
    (with-temp-buffer
      (erc-mode)
      (insert "abc\n")
      (add-text-properties 1 2 (erc--order-text-properties-from-hash table))
      (should (equal '( erc-msg s005
                        erc-ts 0
                        erc-cmd 5
                        a 1
                        b 2
                        c 3)
                     (text-properties-at (point-min)))))))

(ert-deftest erc--check-msg-prop ()
  (let ((erc--msg-props (map-into '((a . 1) (b . x)) 'hash-table)))
    (should (eq 1 (erc--check-msg-prop 'a)))
    (should (erc--check-msg-prop 'a 1))
    (should-not (erc--check-msg-prop 'a 2))

    (should (eq 'x (erc--check-msg-prop 'b)))
    (should (erc--check-msg-prop 'b 'x))
    (should-not (erc--check-msg-prop 'b 1))

    (should (erc--check-msg-prop 'a '(1 42)))
    (should-not (erc--check-msg-prop 'a '(2 42)))

    (let ((props '(42 x)))
      (should (erc--check-msg-prop 'b props)))
    (let ((v '(42 y)))
      (should-not (erc--check-msg-prop 'b v)))))

(defmacro erc-tests--equal-including-properties (a b)
  (list (if (< emacs-major-version 29)
            'ert-equal-including-properties
          'equal-including-properties)
        a b))

(ert-deftest erc--merge-prop ()
  (with-current-buffer (get-buffer-create "*erc-test*")
    ;; Baseline.
    (insert "abc\n")
    (erc--merge-prop 1 3 'erc-test 'x)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("abc" 0 2 (erc-test x))))
    (erc--merge-prop 1 3 'erc-test 'y)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("abc" 0 2 (erc-test (y x)))))

    ;; Multiple intervals.
    (goto-char (point-min))
    (insert "def\n")
    (erc--merge-prop 1 2 'erc-test 'x)
    (erc--merge-prop 2 3 'erc-test 'y)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4)
             #("def" 0 1 (erc-test x) 1 2 (erc-test y))))
    (erc--merge-prop 1 3 'erc-test 'z)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4)
             #("def" 0 1 (erc-test (z x)) 1 2 (erc-test (z y)))))

    ;; New val as list.
    (goto-char (point-min))
    (insert "ghi\n")
    (erc--merge-prop 2 3 'erc-test '(y z))
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("ghi" 1 2 (erc-test (y z)))))
    (erc--merge-prop 1 3 'erc-test '(w x))
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4)
             #("ghi" 0 1 (erc-test (w x)) 1 2 (erc-test (w x y z)))))

    (when noninteractive
      (kill-buffer))))

(ert-deftest erc--remove-from-prop-value-list ()
  (with-current-buffer (get-buffer-create "*erc-test*")
    ;; Non-list match.
    (insert "abc\n")
    (put-text-property 1 2 'erc-test 'a)
    (put-text-property 2 3 'erc-test 'b)
    (put-text-property 3 4 'erc-test 'c)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("abc"
                                      0 1 (erc-test a)
                                      1 2 (erc-test b)
                                      2 3 (erc-test c))))

    (erc--remove-from-prop-value-list 1 4 'erc-test 'b)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("abc"
                                      0 1 (erc-test a)
                                      2 3 (erc-test c))))
    (erc--remove-from-prop-value-list 1 4 'erc-test 'a)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("abc" 2 3 (erc-test c))))
    (erc--remove-from-prop-value-list 1 4 'erc-test 'c)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) "abc"))

    ;; List match.
    (goto-char (point-min))
    (insert "def\n")
    (put-text-property 1 2 'erc-test '(d x))
    (put-text-property 2 3 'erc-test '(e y))
    (put-text-property 3 4 'erc-test '(f z))
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("def"
                                      0 1 (erc-test (d x))
                                      1 2 (erc-test (e y))
                                      2 3 (erc-test (f z)))))
    (erc--remove-from-prop-value-list 1 4 'erc-test 'y)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("def"
                                      0 1 (erc-test (d x))
                                      1 2 (erc-test e)
                                      2 3 (erc-test (f z)))))
    (erc--remove-from-prop-value-list 1 4 'erc-test 'd)
    (erc--remove-from-prop-value-list 1 4 'erc-test 'f)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("def"
                                      0 1 (erc-test x)
                                      1 2 (erc-test e)
                                      2 3 (erc-test z))))
    (erc--remove-from-prop-value-list 1 4 'erc-test 'e)
    (erc--remove-from-prop-value-list 1 4 'erc-test 'z)
    (erc--remove-from-prop-value-list 1 4 'erc-test 'x)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) "def"))

    ;; List match.
    (goto-char (point-min))
    (insert "ghi\n")
    (put-text-property 1 2 'erc-test '(g x))
    (put-text-property 2 3 'erc-test '(h x))
    (put-text-property 3 4 'erc-test '(i y))
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("ghi"
                                      0 1 (erc-test (g x))
                                      1 2 (erc-test (h x))
                                      2 3 (erc-test (i y)))))
    (erc--remove-from-prop-value-list 1 4 'erc-test 'x)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("ghi"
                                      0 1 (erc-test g)
                                      1 2 (erc-test h)
                                      2 3 (erc-test (i y)))))
    (erc--remove-from-prop-value-list 1 2 'erc-test 'g) ; narrowed
    (erc--remove-from-prop-value-list 3 4 'erc-test 'i) ; narrowed
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("ghi"
                                      1 2 (erc-test h)
                                      2 3 (erc-test y))))

    ;; Pathological (,c) case (hopefully not created by ERC)
    (goto-char (point-min))
    (insert "jkl\n")
    (put-text-property 1 2 'erc-test '(j x))
    (put-text-property 2 3 'erc-test '(k))
    (put-text-property 3 4 'erc-test '(k))
    (erc--remove-from-prop-value-list 1 4 'erc-test 'k)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("jkl" 0 1 (erc-test (j x)))))

    (when noninteractive
      (kill-buffer))))

(ert-deftest erc--remove-from-prop-value-list/many ()
  (with-current-buffer (get-buffer-create "*erc-test*")
    ;; Non-list match.
    (insert "abc\n")
    (put-text-property 1 2 'erc-test 'a)
    (put-text-property 2 3 'erc-test 'b)
    (put-text-property 3 4 'erc-test 'c)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("abc"
                                      0 1 (erc-test a)
                                      1 2 (erc-test b)
                                      2 3 (erc-test c))))

    (erc--remove-from-prop-value-list 1 4 'erc-test '(a b))
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("abc" 2 3 (erc-test c))))
    (erc--remove-from-prop-value-list 1 4 'erc-test 'a)
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("abc" 2 3 (erc-test c))))
    (erc--remove-from-prop-value-list 1 4 'erc-test '(c))
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) "abc"))

    ;; List match.
    (goto-char (point-min))
    (insert "def\n")
    (put-text-property 1 2 'erc-test '(d x y))
    (put-text-property 2 3 'erc-test '(e y))
    (put-text-property 3 4 'erc-test '(f z))
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("def"
                                      0 1 (erc-test (d x y))
                                      1 2 (erc-test (e y))
                                      2 3 (erc-test (f z)))))
    (erc--remove-from-prop-value-list 1 4 'erc-test '(d y f))
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("def"
                                      0 1 (erc-test x)
                                      1 2 (erc-test e)
                                      2 3 (erc-test z))))
    (erc--remove-from-prop-value-list 1 4 'erc-test '(e z x))
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) "def"))

    ;; Narrowed beg.
    (goto-char (point-min))
    (insert "ghi\n")
    (put-text-property 1 2 'erc-test '(g x))
    (put-text-property 2 3 'erc-test '(h x))
    (put-text-property 3 4 'erc-test '(i x))
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("ghi"
                                      0 1 (erc-test (g x))
                                      1 2 (erc-test (h x))
                                      2 3 (erc-test (i x)))))
    (erc--remove-from-prop-value-list 1 3 'erc-test '(x g i))
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("ghi"
                                      1 2 (erc-test h)
                                      2 3 (erc-test (i x)))))

    ;; Narrowed middle.
    (goto-char (point-min))
    (insert "jkl\n")
    (put-text-property 1 2 'erc-test '(j x))
    (put-text-property 2 3 'erc-test '(k))
    (put-text-property 3 4 'erc-test '(l y z))
    (erc--remove-from-prop-value-list 3 4 'erc-test '(k x y z))
    (should (erc-tests--equal-including-properties
             (buffer-substring 1 4) #("jkl"
                                      0 1 (erc-test (j x))
                                      1 2 (erc-test (k))
                                      2 3 (erc-test l))))

    (when noninteractive
      (kill-buffer))))

(ert-deftest erc--split-string-shell-cmd ()

  ;; Leading and trailing space
  (should (equal (erc--split-string-shell-cmd "1 2 3") '("1" "2" "3")))
  (should (equal (erc--split-string-shell-cmd " 1  2 3 ") '("1" "2" "3")))

  ;; Empty string
  (should (equal (erc--split-string-shell-cmd "\"\"") '("")))
  (should (equal (erc--split-string-shell-cmd " \"\" ") '("")))
  (should (equal (erc--split-string-shell-cmd "1 \"\"") '("1" "")))
  (should (equal (erc--split-string-shell-cmd "1 \"\" ") '("1" "")))
  (should (equal (erc--split-string-shell-cmd "\"\" 1") '("" "1")))
  (should (equal (erc--split-string-shell-cmd " \"\" 1") '("" "1")))

  (should (equal (erc--split-string-shell-cmd "''") '("")))
  (should (equal (erc--split-string-shell-cmd " '' ") '("")))
  (should (equal (erc--split-string-shell-cmd "1 ''") '("1" "")))
  (should (equal (erc--split-string-shell-cmd "1 '' ") '("1" "")))
  (should (equal (erc--split-string-shell-cmd "'' 1") '("" "1")))
  (should (equal (erc--split-string-shell-cmd " '' 1") '("" "1")))

  ;; Backslash
  (should (equal (erc--split-string-shell-cmd "\\ ") '(" ")))
  (should (equal (erc--split-string-shell-cmd " \\  ") '(" ")))
  (should (equal (erc--split-string-shell-cmd "1\\  ") '("1 ")))
  (should (equal (erc--split-string-shell-cmd "1\\ 2") '("1 2")))

  ;; Embedded
  (should (equal (erc--split-string-shell-cmd "\"\\\"\"") '("\"")))
  (should (equal (erc--split-string-shell-cmd "1 \"2 \\\" \\\" 3\"")
                 '("1" "2 \" \" 3")))
  (should (equal (erc--split-string-shell-cmd "1 \"2 ' ' 3\"")
                 '("1" "2 ' ' 3")))
  (should (equal (erc--split-string-shell-cmd "1 '2 \" \" 3'")
                 '("1" "2 \" \" 3")))
  (should (equal (erc--split-string-shell-cmd "1 '2 \\  3'")
                 '("1" "2 \\  3")))
  (should (equal (erc--split-string-shell-cmd "1 \"2 \\\\  3\"")
                 '("1" "2 \\  3"))) ; see comment re ^

  ;; Realistic
  (should (equal (erc--split-string-shell-cmd "GET bob \"my file.txt\"")
                 '("GET" "bob" "my file.txt")))
  (should (equal (erc--split-string-shell-cmd "GET EXAMPLE|bob \"my file.txt\"")
                 '("GET" "EXAMPLE|bob" "my file.txt")))) ; regression


;; The behavior of `erc-pre-send-functions' differs between versions
;; in how hook members see and influence a trailing newline that's
;; part of the original prompt submission:
;;
;;  5.4: both seen and sent
;;  5.5: seen but not sent*
;;  5.6: neither seen nor sent*
;;
;;  * requires `erc-send-whitespace-lines' for hook to run
;;
;; Two aspects that have remained consistent are
;;
;;   - a final nonempty line in any submission is always sent
;;   - a trailing newline appended by a hook member is always sent
;;
;; The last bullet would seem to contradict the "not sent" behavior of
;; 5.5 and 5.6, but what's actually happening is that exactly one
;; trailing newline is culled, so anything added always goes through.
;; Also, in ERC 5.6, all empty lines are actually padded, but this is
;; merely incidental WRT the above.
;;
;; Note that this test doesn't run any input-prep hooks and thus can't
;; account for the "seen" dimension noted above.

(ert-deftest erc--run-send-hooks ()
  (with-suppressed-warnings ((obsolete erc-send-this)
                             (obsolete erc-send-pre-hook))
    (should erc-insert-this)
    (should erc-send-this) ; populates `erc--input-split-sendp'

    (let (erc-pre-send-functions erc-send-pre-hook)

      (ert-info ("String preserved, lines rewritten, empties padded")
        (setq erc-pre-send-functions
              (lambda (o) (setf (erc-input-string o) "bar\n\nbaz\n")))
        (should (pcase (erc--run-send-hooks (make-erc--input-split
                                             :string "foo" :lines '("foo")))
                  ((cl-struct erc--input-split
                              (string "foo") (sendp 't) (insertp 't)
                              (lines '("bar" " " "baz" " ")) (cmdp 'nil))
                   t))))

      (ert-info ("Multiline commands rejected")
        (should-error (erc--run-send-hooks (make-erc--input-split
                                            :string "/mycmd foo"
                                            :lines '("/mycmd foo")
                                            :cmdp t))))

      (ert-info ("Single-line commands pass")
        (setq erc-pre-send-functions
              (lambda (o) (setf (erc-input-sendp o) nil
                                (erc-input-string o) "/mycmd bar")))
        (should (pcase (erc--run-send-hooks (make-erc--input-split
                                             :string "/mycmd foo"
                                             :lines '("/mycmd foo")
                                             :cmdp t))
                  ((cl-struct erc--input-split
                              (string "/mycmd foo") (sendp 'nil) (insertp 't)
                              (lines '("/mycmd bar")) (cmdp 't))
                   t))))

      (ert-info ("Legacy hook respected, special vars confined")
        (setq erc-send-pre-hook (lambda (_) (setq erc-send-this nil))
              erc-pre-send-functions (lambda (o) ; propagates
                                       (should-not (erc-input-sendp o))))
        (should (pcase (erc--run-send-hooks (make-erc--input-split
                                             :string "foo" :lines '("foo")))
                  ((cl-struct erc--input-split
                              (string "foo") (sendp 'nil) (insertp 't)
                              (lines '("foo")) (cmdp 'nil))
                   t)))
        (should erc-send-this))

      (ert-info ("Request to resplit honored")
        (setq erc-send-pre-hook nil
              erc-pre-send-functions
              (lambda (o) (setf (erc-input-string o) "foo bar baz"
                                (erc-input-refoldp o) t)))
        (let ((erc-split-line-length 8))
          (should
           (pcase (erc--run-send-hooks (make-erc--input-split
                                        :string "foo" :lines '("foo")))
             ((cl-struct erc--input-split
                         (string "foo") (sendp 't) (insertp 't)
                         (lines '("foo bar " "baz")) (cmdp 'nil))
              t))))))))

;; Note: if adding an erc-backend-tests.el, please relocate this there.

(ert-deftest erc-message ()
  (should-not erc-server-last-peers)
  (let (server-proc
        calls
        erc-kill-channel-hook erc-kill-server-hook erc-kill-buffer-hook)
    (cl-letf (((symbol-function 'erc-display-message)
               (lambda (_ _ _ line) (push line calls)))
              ((symbol-function 'erc-server-send)
               (lambda (line _) (push line calls)))
              ((symbol-function 'erc-server-buffer)
               (lambda () (process-buffer server-proc))))
      (with-current-buffer (get-buffer-create "ExampleNet")
        (erc-mode)
        (setq erc-server-current-nick "tester"
              server-proc (start-process "sleep" (current-buffer) "sleep" "1")
              erc-server-process server-proc
              erc-server-last-peers (cons nil nil)
              erc-server-users (make-hash-table :test 'equal)
              erc-network 'ExampleNet)
        (set-process-query-on-exit-flag erc-server-process nil))

      (with-current-buffer (get-buffer-create "#chan")
        (erc-mode)
        (setq erc-server-process (buffer-local-value 'erc-server-process
                                                     (get-buffer "ExampleNet"))
              erc--target (erc--target-from-string "#chan")
              erc-default-recipients '("#chan")
              erc-channel-users (make-hash-table :test 'equal)
              erc-network 'ExampleNet)
        (erc-update-current-channel-member "alice" "alice")
        (erc-update-current-channel-member "tester" "tester"))

      (with-current-buffer "ExampleNet"
        (erc-server-PRIVMSG erc-server-process
                            (make-erc-response
                             :sender "alice!~u@fsf.org"
                             :command "PRIVMSG"
                             :command-args '("#chan" "hi")
                             :unparsed ":alice!~u@fsf.org PRIVMSG #chan :hi"))
        (should (equal erc-server-last-peers '("alice")))
        (should (string-match "<alice>" (pop calls))))

      (with-current-buffer "#chan"
        (ert-info ("Shortcuts usable in target buffers")
          (should-not (local-variable-p 'erc-server-last-peers))
          (should-not erc-server-last-peers)
          (erc-message "PRIVMSG" ". hi")
          (should-not erc-server-last-peers)
          (should (eq 'no-target (pop calls)))
          (erc-message "PRIVMSG" ", hi")
          (should-not erc-server-last-peers)
          (should (string-match "alice :hi" (pop calls)))))

      (with-current-buffer "ExampleNet"
        (ert-info ("Shortcuts local in server bufs")
          (should (equal erc-server-last-peers '("alice" . "alice")))
          (erc-message "PRIVMSG" ", hi")
          (should (equal erc-server-last-peers '("alice" . "alice")))
          (should (string-match "PRIVMSG alice :hi" (pop calls)))
          (setcdr erc-server-last-peers "bob")
          (erc-message "PRIVMSG" ". hi")
          (should (equal erc-server-last-peers '("alice" . "bob")))
          (should (string-match "PRIVMSG bob :hi" (pop calls)))))

      (with-current-buffer "#chan"
        (ert-info ("Non-shortcuts are local to server buffer")
          (should-not (local-variable-p 'erc-server-last-peers))
          (should-not erc-server-last-peers)
          (erc-message "PRIVMSG" "#chan hola")
          (should-not erc-server-last-peers)
          (should-not (default-value 'erc-server-last-peers))
          (should (equal (buffer-local-value 'erc-server-last-peers
                                             (get-buffer "ExampleNet"))
                         '("alice" . "#chan")))
          (should (string-match "hola" (pop calls))))))

    (should-not erc-server-last-peers)
    (should-not calls)
    (kill-buffer "ExampleNet")
    (kill-buffer "#chan")))

(ert-deftest erc-format-privmessage ()
  ;; Basic PRIVMSG
  (should (erc-tests--equal-including-properties
           (erc-format-privmessage (copy-sequence "bob")
                                   (copy-sequence "oh my")
                                   nil 'msgp)
           #("<bob> oh my"
             0 1 (font-lock-face erc-default-face)
             1 4 (erc-speaker "bob" font-lock-face erc-nick-default-face)
             4 11 (font-lock-face erc-default-face))))

  ;; Basic NOTICE
  (should (erc-tests--equal-including-properties
           (erc-format-privmessage (copy-sequence "bob")
                                   (copy-sequence "oh my")
                                   nil nil)
           #("-bob- oh my"
             0 1 (font-lock-face erc-default-face)
             1 4 (erc-speaker "bob" font-lock-face erc-nick-default-face)
             4 11 (font-lock-face erc-default-face))))

  ;; Prefixed PRIVMSG
  (let* ((user (make-erc-server-user :nickname (copy-sequence "Bob")))
         (cuser (make-erc-channel-user :op t))
         (erc-channel-users (make-hash-table :test #'equal)))
    (puthash "bob" (cons user cuser) erc-channel-users)

    (should (erc-tests--equal-including-properties
             (erc-format-privmessage (erc-format-@nick user cuser)
                                     (copy-sequence "oh my")
                                     nil 'msgp)
             #("<@Bob> oh my"
               0 1 (font-lock-face erc-default-face)
               1 2 (font-lock-face erc-nick-prefix-face help-echo "operator")
               2 5 (erc-speaker "Bob" font-lock-face erc-nick-default-face)
               5 12 (font-lock-face erc-default-face))))))

(ert-deftest erc--route-insertion ()
  (erc-tests--send-prep)
  (erc-tests--set-fake-server-process "sleep" "1")
  (setq erc-networks--id (erc-networks--id-create 'foonet))

  (let* ((erc-modules) ; for `erc--open-target'
         (server-buffer (current-buffer))
         (spam-buffer (save-excursion (erc--open-target "#spam")))
         (chan-buffer (save-excursion (erc--open-target "#chan")))
         calls)
    (cl-letf (((symbol-function 'erc-insert-line)
               (lambda (&rest r) (push (cons 'line-1 r) calls))))

      (with-current-buffer chan-buffer

        (ert-info ("Null `buffer' routes to live server-buffer")
          (erc--route-insertion "null" nil)
          (should (equal (pop calls) `(line-1 "null" ,server-buffer)))
          (should-not calls))

        (ert-info ("Cons `buffer' routes to live members")
          ;; Copies a let-bound `erc--msg-props' before mutating.
          (let* ((table (map-into '(erc-msg msg) 'hash-table))
                 (erc--msg-props table))
            (erc--route-insertion "cons" (list server-buffer spam-buffer))
            (should-not (eq table erc--msg-props)))
          (should (equal (pop calls) `(line-1 "cons" ,spam-buffer)))
          (should (equal (pop calls) `(line-1 "cons" ,server-buffer)))
          (should-not calls))

        (ert-info ("Variant `all' inserts in all session buffers")
          (erc--route-insertion "all" 'all)
          (should (equal (pop calls) `(line-1 "all" ,chan-buffer)))
          (should (equal (pop calls) `(line-1 "all" ,spam-buffer)))
          (should (equal (pop calls) `(line-1 "all" ,server-buffer)))
          (should-not calls))

        (ert-info ("Variant `active' routes to active buffer if alive")
          (should (eq chan-buffer (erc-with-server-buffer erc-active-buffer)))
          (erc-set-active-buffer spam-buffer)
          (erc--route-insertion "act" 'active)
          (should (equal (pop calls) `(line-1 "act" ,spam-buffer)))
          (should (eq (erc-active-buffer) spam-buffer))
          (should-not calls))

        (ert-info ("Variant `active' falls back to current buffer")
          (should (eq spam-buffer (erc-active-buffer)))
          (kill-buffer "#spam")
          (erc--route-insertion "nact" 'active)
          (should (equal (pop calls) `(line-1 "nact" ,server-buffer)))
          (should (eq (erc-with-server-buffer erc-active-buffer)
                      server-buffer))
          (should-not calls))

        (ert-info ("Dead single buffer defaults to live server-buffer")
          (should-not (get-buffer "#spam"))
          (erc--route-insertion "dead" 'spam-buffer)
          (should (equal (pop calls) `(line-1 "dead" ,server-buffer)))
          (should-not calls))))

    (should-not (buffer-live-p spam-buffer))
    (kill-buffer chan-buffer)))

(defvar erc-tests--ipv6-examples
  '("1:2:3:4:5:6:7:8"
    "::ffff:10.0.0.1" "::ffff:1.2.3.4" "::ffff:0.0.0.0"
    "1:2:3:4:5:6:77:88" "::ffff:255.255.255.255"
    "fe08::7:8" "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff"
    "1:2:3:4:5:6:7:8" "1::" "1:2:3:4:5:6:7::" "1::8"
    "1:2:3:4:5:6::8" "1:2:3:4:5:6::8" "1::7:8" "1:2:3:4:5::7:8"
    "1:2:3:4:5::8" "1::6:7:8" "1:2:3:4::6:7:8" "1:2:3:4::8"
    "1::5:6:7:8" "1:2:3::5:6:7:8" "1:2:3::8" "1::4:5:6:7:8"
    "1:2::4:5:6:7:8" "1:2::8" "1::3:4:5:6:7:8" "1::3:4:5:6:7:8"
    "1::8" "::2:3:4:5:6:7:8" "::2:3:4:5:6:7:8" "::8"
    "::" "fe08::7:8%eth0" "fe08::7:8%1" "::255.255.255.255"
    "::ffff:255.255.255.255" "::ffff:0:255.255.255.255"
    "2001:db8:3:4::192.0.2.33" "64:ff9b::192.0.2.33"))

(ert-deftest erc--server-connect-dumb-ipv6-regexp ()
  (dolist (a erc-tests--ipv6-examples)
    (should-not (string-match erc--server-connect-dumb-ipv6-regexp a))
    (should (string-match erc--server-connect-dumb-ipv6-regexp
                          (concat "[" a "]")))))

(ert-deftest erc--with-entrypoint-environment ()
  (let ((env '((erc-join-buffer . foo)
               (erc-server-connect-function . bar))))
    (erc--with-entrypoint-environment env
      (should (eq erc-join-buffer 'foo))
      (should (eq erc-server-connect-function 'bar)))))

(ert-deftest erc-select-read-args ()

  (ert-info ("Prompts for switch to TLS by default")
    (should (equal (ert-simulate-keys "\r\r\r\ry\r"
                     (erc-select-read-args))
                   (list :server "irc.libera.chat"
                         :port 6697
                         :nick (user-login-name)
                         '&interactive-env
                         '((erc-server-connect-function . erc-open-tls-stream)
                           (erc-join-buffer . window))))))

  (ert-info ("Switches to TLS when port matches default TLS port")
    (should (equal (ert-simulate-keys "irc.gnu.org\r6697\r\r\r"
                     (erc-select-read-args))
                   (list :server "irc.gnu.org"
                         :port 6697
                         :nick (user-login-name)
                         '&interactive-env
                         '((erc-server-connect-function . erc-open-tls-stream)
                           (erc-join-buffer . window))))))

  (ert-info ("Switches to TLS when URL is ircs://")
    (let ((erc--display-context '((erc-interactive-display . erc))))
      (should (equal (ert-simulate-keys "ircs://irc.gnu.org\r\r\r\r"
                       (erc-select-read-args))
                     (list :server "irc.gnu.org"
                           :port 6697
                           :nick (user-login-name)
                           '&interactive-env
                           '((erc-server-connect-function
                              . erc-open-tls-stream)
                             (erc--display-context
                              . ((erc-interactive-display . erc)))
                             (erc-join-buffer . window)))))))

  (setq-local erc-interactive-display nil) ; cheat to save space

  (ert-info ("Opt out of non-TLS warning manually")
    (should (equal (ert-simulate-keys "\r\r\r\rn\r"
                     (erc-select-read-args))
                   (list :server "irc.libera.chat"
                         :port 6667
                         :nick (user-login-name)))))

  (ert-info ("Override default TLS")
    (should (equal (ert-simulate-keys "irc://irc.libera.chat\r\r\r\r"
                     (erc-select-read-args))
                   (list :server "irc.libera.chat"
                         :port 6667
                         :nick (user-login-name)))))

  (ert-info ("Address includes port")
    (should (equal (ert-simulate-keys "localhost:6667\rnick\r\r"
                     (erc-select-read-args))
                   (list :server "localhost"
                         :port 6667
                         :nick "nick"))))

  (ert-info ("Address includes nick, password skipped via option")
    (should (equal (ert-simulate-keys "nick@localhost:6667\r"
                     (let (erc-prompt-for-password)
                       (erc-select-read-args)))
                   (list :server "localhost"
                         :port 6667
                         :nick "nick"))))

  (ert-info ("Address includes nick and password")
    (should (equal (ert-simulate-keys "nick:sesame@localhost:6667\r\r"
                     (erc-select-read-args))
                   (list :server "localhost"
                         :port 6667
                         :nick "nick"
                         :password "sesame"))))

  (ert-info ("IPv6 address plain")
    (should (equal (ert-simulate-keys "::1\r\r\r\r"
                     (erc-select-read-args))
                   (list :server "[::1]"
                         :port 6667
                         :nick (user-login-name)))))

  (ert-info ("IPv6 address with port")
    (should (equal (ert-simulate-keys "[::1]:6667\r\r\r"
                     (erc-select-read-args))
                   (list :server "[::1]"
                         :port 6667
                         :nick (user-login-name)))))

  (ert-info ("IPv6 address includes nick")
    (should (equal (ert-simulate-keys "nick@[::1]:6667\r\r"
                     (erc-select-read-args))
                   (list :server "[::1]"
                         :port 6667
                         :nick "nick"))))

  (ert-info ("Extra args use URL nick by default")
    (should (equal (ert-simulate-keys "nick:sesame@localhost:6667\r\r\r\r"
                     (let ((current-prefix-arg '(4)))
                       (erc-select-read-args)))
                   (list :server "localhost"
                         :port 6667
                         :nick "nick"
                         :user "nick"
                         :password "sesame"
                         :full-name "nick")))))

(ert-deftest erc-tls ()
  (let (calls env)
    (cl-letf (((symbol-function 'user-login-name)
               (lambda (&optional _) "tester"))
              ((symbol-function 'erc-open)
               (lambda (&rest r)
                 (push `((erc-join-buffer ,erc-join-buffer)
                         (erc--display-context ,@erc--display-context)
                         (erc-server-connect-function
                          ,erc-server-connect-function))
                       env)
                 (push r calls))))

      (ert-info ("Defaults")
        (erc-tls)
        (should (equal (pop calls)
                       '("irc.libera.chat" 6697 "tester" "unknown" t
                         nil nil nil nil nil "user" nil)))
        (should (equal (pop env)
                       '((erc-join-buffer bury)
                         (erc--display-context (erc-buffer-display . erc-tls))
                         (erc-server-connect-function erc-open-tls-stream)))))

      (ert-info ("Full")
        (erc-tls :server "irc.gnu.org"
                 :port 7000
                 :user "bobo"
                 :nick "bob"
                 :full-name "Bob's Name"
                 :password "bob:changeme"
                 :client-certificate t
                 :id 'GNU.org)
        (should (equal (pop calls)
                       '("irc.gnu.org" 7000 "bob" "Bob's Name" t
                         "bob:changeme" nil nil nil t "bobo" GNU.org)))
        (should (equal (pop env)
                       '((erc-join-buffer bury)
                         (erc--display-context (erc-buffer-display . erc-tls))
                         (erc-server-connect-function erc-open-tls-stream)))))

      ;; Values are often nil when called by lisp code, which leads to
      ;; null params.  This is why `erc-open' recomputes almost
      ;; everything.
      (ert-info ("Fallback")
        (let ((erc-nick "bob")
              (erc-server "irc.gnu.org")
              (erc-email-userid "bobo")
              (erc-user-full-name "Bob's Name"))
          (erc-tls :server nil
                   :port 7000
                   :nick nil
                   :password "bob:changeme"))
        (should (equal (pop calls)
                       '(nil 7000 nil "Bob's Name" t
                             "bob:changeme" nil nil nil nil "bobo" nil)))
        (should (equal (pop env)
                       '((erc-join-buffer bury)
                         (erc--display-context (erc-buffer-display . erc-tls))
                         (erc-server-connect-function erc-open-tls-stream)))))

      (ert-info ("Interactive")
        (ert-simulate-keys "nick:sesame@localhost:6667\r\r"
          (call-interactively #'erc-tls))
        (should (equal (pop calls)
                       '("localhost" 6667 "nick" "unknown" t "sesame"
                         nil nil nil nil "user" nil)))
        (should (equal (pop env)
                       '((erc-join-buffer window)
                         (erc--display-context
                          (erc-interactive-display . erc-tls))
                         (erc-server-connect-function erc-open-tls-stream)))))

      (ert-info ("Custom connect function")
        (let ((erc-server-connect-function 'my-connect-func))
          (erc-tls)
          (should (equal (pop calls)
                         '("irc.libera.chat" 6697 "tester" "unknown" t
                           nil nil nil nil nil "user" nil)))
          (should (equal (pop env)
                         '((erc-join-buffer bury)
                           (erc--display-context
                            (erc-buffer-display . erc-tls))
                           (erc-server-connect-function my-connect-func))))))

      (ert-info ("Advised default function overlooked") ; intentional
        (advice-add 'erc-server-connect-function :around #'ignore
                    '((name . erc-tests--erc-tls)))
        (erc-tls)
        (should (equal (pop calls)
                       '("irc.libera.chat" 6697 "tester" "unknown" t
                         nil nil nil nil nil "user" nil)))
        (should (equal (pop env)
                       '((erc-join-buffer bury)
                         (erc--display-context (erc-buffer-display . erc-tls))
                         (erc-server-connect-function erc-open-tls-stream))))
        (advice-remove 'erc-server-connect-function 'erc-tests--erc-tls))

      (ert-info ("Advised non-default function honored")
        (let ((f (lambda (&rest r) (ignore r))))
          (cl-letf (((symbol-value 'erc-server-connect-function) f))
            (advice-add 'erc-server-connect-function :around #'ignore
                        '((name . erc-tests--erc-tls)))
            (erc-tls)
            (should (equal (pop calls)
                           '("irc.libera.chat" 6697 "tester" "unknown" t
                             nil nil nil nil nil "user" nil)))
            (should (equal (pop env) `((erc-join-buffer bury)
                                       (erc--display-context
                                        (erc-buffer-display . erc-tls))
                                       (erc-server-connect-function ,f))))
            (advice-remove 'erc-server-connect-function
                           'erc-tests--erc-tls)))))))

;; See `erc-select-read-args' above for argument parsing.
;; This only tests the "hidden" arguments.

(ert-deftest erc--interactive ()
  (let (calls env)
    (cl-letf (((symbol-function 'user-login-name)
               (lambda (&optional _) "tester"))
              ((symbol-function 'erc-open)
               (lambda (&rest r)
                 (push `((erc-join-buffer ,erc-join-buffer)
                         (erc--display-context ,@erc--display-context)
                         (erc-server-connect-function
                          ,erc-server-connect-function))
                       env)
                 (push r calls))))

      (ert-info ("Default click-through accept TLS upgrade")
        (ert-simulate-keys "\r\r\r\ry\r"
          (call-interactively #'erc))
        (should (equal (pop calls)
                       '("irc.libera.chat" 6697 "tester" "unknown" t nil
                         nil nil nil nil "user" nil)))
        (should (equal (pop env)
                       '((erc-join-buffer window)
                         (erc--display-context (erc-interactive-display . erc))
                         (erc-server-connect-function erc-open-tls-stream)))))

      (ert-info ("Nick supplied, decline TLS upgrade")
        (ert-simulate-keys "\r\rdummy\r\rn\r"
          (call-interactively #'erc))
        (should (equal (pop calls)
                       '("irc.libera.chat" 6667 "dummy" "unknown" t nil
                         nil nil nil nil "user" nil)))
        (should (equal (pop env)
                       '((erc-join-buffer window)
                         (erc--display-context (erc-interactive-display . erc))
                         (erc-server-connect-function
                          erc-open-network-stream))))))))

(ert-deftest erc-server-select ()
  (let (calls env)
    (cl-letf (((symbol-function 'user-login-name)
               (lambda (&optional _) "tester"))
              ((symbol-function 'erc-open)
               (lambda (&rest r)
                 (push `((erc-join-buffer ,erc-join-buffer)
                         (erc--display-context ,@erc--display-context)
                         (erc-server-connect-function
                          ,erc-server-connect-function))
                       env)
                 (push r calls))))

      (ert-info ("Selects Libera.Chat Europe, automatic TSL")
        (ert-simulate-keys "Libera.Chat\rirc.eu.\t\r\r\r"
          (with-suppressed-warnings ((obsolete erc-server-select))
            (call-interactively #'erc-server-select)))
        (should (equal (pop calls)
                       '("irc.eu.libera.chat" 6697 "tester" "unknown" t nil
                         nil nil nil nil "user" nil)))
        (should (equal (pop env)
                       '((erc-join-buffer window)
                         (erc--display-context (erc-interactive-display . erc))
                         (erc-server-connect-function erc-open-tls-stream)))))

      (ert-info ("Selects entry that doesn't support TLS")
        (ert-simulate-keys "IRCnet\rirc.fr.\t\rdummy\r\r"
          (with-suppressed-warnings ((obsolete erc-server-select))
            (call-interactively #'erc-server-select)))
        (should (equal (pop calls)
                       '("irc.fr.ircnet.net" 6667 "dummy" "unknown" t nil
                         nil nil nil nil "user" nil)))
        (should (equal (pop env)
                       '((erc-join-buffer window)
                         (erc--display-context (erc-interactive-display . erc))
                         (erc-server-connect-function
                          erc-open-network-stream))))))))

(defun erc-tests--make-server-buf (name)
  (with-current-buffer (get-buffer-create name)
    (erc-mode)
    (setq erc-server-process (start-process "sleep" (current-buffer)
                                            "sleep" "1")
          erc-session-server (concat "irc." name ".org")
          erc-session-port 6667
          erc-network (intern name))
    (set-process-query-on-exit-flag erc-server-process nil)
    (current-buffer)))

(defun erc-tests--make-client-buf (server name)
  (unless (bufferp server)
    (setq server (get-buffer server)))
  (with-current-buffer (get-buffer-create name)
    (erc-mode)
    (setq erc--target (erc--target-from-string name))
    (dolist (v '(erc-server-process
                 erc-session-server
                 erc-session-port
                 erc-network))
      (set v (buffer-local-value v server)))
    (current-buffer)))

(ert-deftest erc-handle-irc-url ()
  (let* (calls
         rvbuf
         erc-networks-alist
         erc-kill-channel-hook erc-kill-server-hook erc-kill-buffer-hook
         (erc-url-connect-function
          (lambda (&rest r)
            (push r calls)
            (if (functionp rvbuf) (funcall rvbuf) rvbuf))))

    (cl-letf (((symbol-function 'erc-cmd-JOIN)
               (lambda (&rest r) (push r calls))))

      (with-current-buffer (erc-tests--make-server-buf "foonet")
        (setq rvbuf (current-buffer)))
      (erc-tests--make-server-buf "barnet")
      (erc-tests--make-server-buf "baznet")

      (ert-info ("Unknown network")
        (erc-handle-irc-url "irc.foonet.org" 6667 "#chan" nil nil "irc")
        (should (equal '("#chan" nil) (pop calls)))
        (should-not calls))

      (ert-info ("Unknown network, no port")
        (erc-handle-irc-url "irc.foonet.org" nil "#chan" nil nil "irc")
        (should (equal '("#chan" nil) (pop calls)))
        (should-not calls))

      (ert-info ("Known network, no port")
        (setq erc-networks-alist '((foonet "irc.foonet.org")))
        (erc-handle-irc-url "irc.foonet.org" nil "#chan" nil nil "irc")
        (should (equal '("#chan" nil) (pop calls)))
        (should-not calls))

      (ert-info ("Known network, different port")
        (erc-handle-irc-url "irc.foonet.org" 6697 "#chan" nil nil "irc")
        (should (equal '("#chan" nil) (pop calls)))
        (should-not calls))

      (ert-info ("Known network, existing chan with key")
        (erc-tests--make-client-buf "foonet" "#chan")
        (erc-handle-irc-url "irc.foonet.org" nil "#chan?sec" nil nil "irc")
        (should (equal '("#chan" "sec") (pop calls)))
        (should-not calls))

      (ert-info ("Unknown network, connect, no chan")
        (erc-handle-irc-url "irc.gnu.org" nil nil nil nil "irc")
        (should (equal '("irc" :server "irc.gnu.org") (pop calls)))
        (should-not calls))

      (ert-info ("Unknown network, connect, chan")
        (with-current-buffer "foonet"
          (should-not (local-variable-p 'erc-after-connect)))
        (setq rvbuf (lambda () (erc-tests--make-server-buf "gnu")))
        (erc-handle-irc-url "irc.gnu.org" nil "#spam" nil nil "irc")
        (should (equal '("irc" :server "irc.gnu.org") (pop calls)))
        (should-not calls)
        (with-current-buffer "gnu"
          (should (local-variable-p 'erc-after-connect))
          (funcall (car erc-after-connect))
          (should (equal '("#spam" nil) (pop calls)))
          (should-not (local-variable-p 'erc-after-connect)))
        (should-not calls))))

  (when noninteractive
    (kill-buffer "foonet")
    (kill-buffer "barnet")
    (kill-buffer "baznet")
    (kill-buffer "#chan")))

(defconst erc-tests--modules
  '( autoaway autojoin bufbar button capab-identify completion dcc fill identd
     imenu irccontrols keep-place list log match menu move-to-prompt netsplit
     networks nickbar nicks noncommands notifications notify page readonly
     replace ring sasl scrolltobottom services smiley sound
     spelling stamp track truncate unmorse xdcc))

;; Ensure that `:initialize' doesn't change the ordering of the
;; members because otherwise the widget's state is "edited".

(ert-deftest erc-modules--initialize ()
  ;; This is `custom--standard-value' from Emacs 28.
  (should (equal (eval (car (get 'erc-modules 'standard-value)) t)
                 erc-modules)))

;; Ensure the `:initialize' function for `erc-modules' successfully
;; tags all built-in modules with the internal property `erc--module'.

(ert-deftest erc-modules--internal-property ()
  (let (ours)
    (mapatoms (lambda (s)
                (when-let ((v (get s 'erc--module))
                           ((eq v s)))
                  (push s ours))))
    (should (equal (sort ours #'string-lessp) erc-tests--modules))))

(ert-deftest erc--normalize-module-symbol ()
  (dolist (mod erc-tests--modules)
    (should (eq (erc--normalize-module-symbol mod) mod)))
  (should (eq (erc--normalize-module-symbol 'pcomplete) 'completion))
  (should (eq (erc--normalize-module-symbol 'Completion) 'completion))
  (should (eq (erc--normalize-module-symbol 'ctcp-page) 'page))
  (should (eq (erc--normalize-module-symbol 'ctcp-sound) 'sound))
  (should (eq (erc--normalize-module-symbol 'timestamp) 'stamp))
  (should (eq (erc--normalize-module-symbol 'nickserv) 'services)))

(defun erc-tests--assert-printed-in-subprocess (code expected)
  (let* ((package (if-let* ((found (getenv "ERC_PACKAGE_NAME"))
                            ((string-prefix-p "erc-" found)))
                      (intern found)
                    'erc))
         ;; This is for integrations testing with managed configs
         ;; ("starter kits") that use a different package manager.
         (init (and-let* ((found (getenv "ERC_TESTS_INIT"))
                          (files (split-string found ",")))
                 (mapcan (lambda (f) (list "-l" f)) files)))
         (prog
          `(progn
             ,@(and (not init) (featurep 'compat)
                    `((require 'package)
                      (let ((package-load-list '((compat t) (,package t))))
                        (package-initialize))))
             (require 'erc)
             (cl-assert (equal erc-version ,erc-version) t)
             ,code))
         (proc (apply #'start-process
                      (symbol-name (ert-test-name (ert-running-test)))
                      (current-buffer)
                      (concat invocation-directory invocation-name)
                      `("-batch" ,@(or init '("-Q"))
                        "-eval" ,(format "%S" prog)))))
    (set-process-query-on-exit-flag proc t)
    (while (accept-process-output proc 10))
    (goto-char (point-min))
    (unless (equal (read (current-buffer)) expected)
      (message "Exepcted: %S\nGot: %s" expected (buffer-string))
      (ert-fail "Mismatch"))))

;; Worrying about which library a module comes from is mostly not
;; worth the hassle so long as ERC can find its minor mode.  However,
;; bugs involving multiple modules living in the same library may slip
;; by because a module's loading problems may remain hidden on account
;; of its place in the default ordering.

(ert-deftest erc--find-mode ()
  (erc-tests--assert-printed-in-subprocess
   `(let ((mods (mapcar #'cadddr (cdddr (get 'erc-modules 'custom-type))))
          moded)
      (setq mods (sort mods (lambda (a b) (if (zerop (random 2)) a b))))
      (dolist (mod mods)
        (unless (keywordp mod)
          (push (if-let ((mode (erc--find-mode mod))) mod (list :missing mod))
                moded)))
      (message "%S"
               (sort moded (lambda (a b)
                             (string< (symbol-name a) (symbol-name b))))))
   erc-tests--modules))

(ert-deftest erc--essential-hook-ordering ()
  (erc-tests--assert-printed-in-subprocess
   '(progn
      (erc-update-modules)
      (message "%S"
               (list :erc-insert-modify-hook erc-insert-modify-hook
                     :erc-send-modify-hook erc-send-modify-hook)))

   '( :erc-insert-modify-hook (erc-controls-highlight ; 0
                               erc-button-add-buttons ; 30
                               erc-match-message ; 50
                               erc-fill ; 60
                               erc-add-timestamp) ; 70

      :erc-send-modify-hook ( erc-controls-highlight ; 0
                              erc-button-add-buttons ; 30
                              erc-fill ; 40
                              erc-add-timestamp)))) ; 70

(ert-deftest erc-migrate-modules ()
  (should (equal (erc-migrate-modules '(autojoin timestamp button))
                 '(autojoin stamp button)))
  ;; Default unchanged
  (should (equal (erc-migrate-modules erc-modules) erc-modules)))

(ert-deftest erc--find-group ()
  ;; These two are loaded by default
  (should (eq (erc--find-group 'keep-place nil) 'erc))
  (should (eq (erc--find-group 'networks nil) 'erc-networks))
  ;; These are fake
  (cl-letf (((get 'erc-bar 'group-documentation) "")
            ((get 'baz 'erc-group) 'erc-foo))
    (should (eq (erc--find-group 'foo 'bar) 'erc-bar))
    (should (eq (erc--find-group 'bar 'foo) 'erc-bar))
    (should (eq (erc--find-group 'bar nil) 'erc-bar))
    (should (eq (erc--find-group 'foo nil) 'erc))
    (should (eq (erc--find-group 'fake 'baz) 'erc-foo))))

(ert-deftest erc--find-group--real ()
  :tags '(:unstable)
  (require 'erc-services)
  (require 'erc-stamp)
  (require 'erc-sound)
  (require 'erc-page)
  (require 'erc-join)
  (require 'erc-capab)
  (require 'erc-pcomplete)
  (should (eq (erc--find-group 'services 'nickserv) 'erc-services))
  (should (eq (erc--find-group 'stamp 'timestamp) 'erc-stamp))
  (should (eq (erc--find-group 'sound 'ctcp-sound) 'erc-sound))
  (should (eq (erc--find-group 'page 'ctcp-page) 'erc-page))
  (should (eq (erc--find-group 'autojoin) 'erc-autojoin))
  (should (eq (erc--find-group 'pcomplete 'Completion) 'erc-pcomplete))
  (should (eq (erc--find-group 'capab-identify) 'erc-capab))
  ;; No group specified.
  (should (eq (erc--find-group 'smiley nil) 'erc))
  (should (eq (erc--find-group 'unmorse nil) 'erc)))

(ert-deftest erc--sort-modules ()
  (should (equal (erc--sort-modules '(networks foo fill bar fill stamp bar))
                 ;; Third-party mods appear in original order.
                 '(fill networks stamp foo bar))))

(defun erc-tests--update-modules (fn)
  (let* ((calls nil)
         (custom-modes nil)
         (on-load nil)
         (text-quoting-style 'grave)

         (get-calls (lambda () (prog1 (nreverse calls) (setq calls nil))))

         (add-onload (lambda (m k v)
                       (put (intern m) 'erc--feature k)
                       (push (cons k (lambda () (funcall v m))) on-load)))

         (mk-cmd (lambda (module)
                   (let ((mode (intern (format "erc-%s-mode" module))))
                     (fset mode (lambda (n) (push (cons mode n) calls))))))

         (mk-builtin (lambda (module-string)
                       (let ((s (intern module-string)))
                         (put s 'erc--module s))))

         (mk-global (lambda (module)
                      (push (intern (format "erc-%s-mode" module))
                            custom-modes))))

    (cl-letf (((symbol-function 'require)
               (lambda (s &rest _)
                 ;; Simulate library being loaded, things defined.
                 (when-let ((h (alist-get s on-load))) (funcall h))
                 (push (cons 'req s) calls)))

              ;; Spoof global module detection.
              ((symbol-function 'custom-variable-p)
               (lambda (v) (memq v custom-modes))))

      (funcall fn get-calls add-onload mk-cmd mk-builtin mk-global))
    (should-not erc--aberrant-modules)))

(ert-deftest erc--update-modules/unknown ()
  (erc-tests--update-modules

   (lambda (get-calls _ mk-cmd _ mk-global)

     (ert-info ("Baseline")
       (let* ((erc-modules '(foo))
              (obarray (obarray-make))
              (err (should-error (erc--update-modules erc-modules))))
         (should (equal (cadr err) "`foo' is not a known ERC module"))
         (should (equal (mapcar #'prin1-to-string (funcall get-calls))
                        '("(req . erc-foo)")))))

     ;; Module's mode command exists but lacks an associated file.
     (ert-info ("Bad autoload flagged as suspect")
       (should-not erc--aberrant-modules)
       (let* ((erc--aberrant-modules nil)
              (obarray (obarray-make))
              (erc-modules (list (intern "foo"))))

         ;; Create a mode-activation command and make mode-var global.
         (funcall mk-cmd "foo")
         (funcall mk-global "foo")

         ;; No local modules to return.
         (should-not (erc--update-modules erc-modules))
         (should (equal (mapcar #'prin1-to-string erc--aberrant-modules)
                        '("foo")))
         ;; ERC requires the library via prefixed module name.
         (should (equal (mapcar #'prin1-to-string (funcall get-calls))
                        '("(req . erc-foo)" "(erc-foo-mode . 1)"))))))))

;; A local module (here, `lo2') lacks a mode toggle, so ERC tries to
;; load its defining library, first via the symbol property
;; `erc--feature', and then via an "erc-" prefixed symbol.
(ert-deftest erc--update-modules/local ()
  (erc-tests--update-modules

   (lambda (get-calls add-onload mk-cmd mk-builtin mk-global)

     (let* ((obarray (obarray-make 20))
            (erc-modules (mapcar #'intern '("glo" "lo1" "lo2"))))

       ;; Create a global and a local module.
       (mapc mk-cmd '("glo" "lo1"))
       (mapc mk-builtin '("glo" "lo1"))
       (funcall mk-global "glo")
       (funcall add-onload "lo2" 'explicit-feature-lib mk-cmd)

       ;; Returns local modules.
       (should (equal (mapcar #'symbol-name (erc--update-modules erc-modules))
                      '("erc-lo2-mode" "erc-lo1-mode")))

       ;; Requiring `erc-lo2' defines `erc-lo2-mode'.
       (should (equal (mapcar #'prin1-to-string (funcall get-calls))
                      `("(erc-glo-mode . 1)"
                        "(req . explicit-feature-lib)")))))))

(ert-deftest erc--update-modules/realistic ()
  (let ((calls nil)
        ;; Module `pcomplete' "resolves" to `completion'.
        (erc-modules '(pcomplete autojoin networks)))
    (cl-letf (((symbol-function 'require)
               (lambda (s &rest _) (push (cons 'req s) calls)))

              ;; Spoof global module detection.
              ((symbol-function 'custom-variable-p)
               (lambda (v)
                 (memq v '(erc-autojoin-mode erc-networks-mode
                                             erc-completion-mode))))
              ;; Mock and spy real builtins.
              ((symbol-function 'erc-autojoin-mode)
               (lambda (n) (push (cons 'autojoin n) calls)))
              ((symbol-function 'erc-networks-mode)
               (lambda (n) (push (cons 'networks n) calls)))
              ((symbol-function 'erc-completion-mode)
               (lambda (n) (push (cons 'completion n) calls))))

      (should-not (erc--update-modules erc-modules)) ; no locals
      (should (equal (nreverse calls)
                     '((completion . 1) (autojoin . 1) (networks . 1)))))))

(ert-deftest erc--merge-local-modes ()
  (cl-letf (((get 'erc-b-mode 'erc-module) 'b)
            ((get 'erc-c-mode 'erc-module) 'c)
            ((get 'erc-d-mode 'erc-module) 'd)
            ((get 'erc-e-mode 'erc-module) 'e))

    (ert-info ("No existing modes")
      (let ((old '((a) (b . t)))
            (new '(erc-c-mode erc-d-mode)))
        (should (equal (erc--merge-local-modes new old)
                       '((erc-c-mode erc-d-mode))))))

    (ert-info ("Active existing added, inactive existing removed, deduped")
      (let ((old '((a) (erc-b-mode) (c . t) (erc-d-mode . t) (erc-e-mode . t)))
            (new '(erc-b-mode erc-d-mode)))
        (should (equal (erc--merge-local-modes new old)
                       '((erc-d-mode erc-e-mode) . (erc-b-mode))))))

    (ert-info ("Non-module erc-prefixed mode ignored")
      (let ((old '((erc-b-mode) (erc-f-mode . t) (erc-d-mode . t)))
            (new '(erc-b-mode)))
        (should (equal (erc--merge-local-modes new old)
                       '((erc-d-mode) . (erc-b-mode))))))))

(ert-deftest define-erc-module--global ()
  (let ((global-module '(define-erc-module mname malias
                          "Some docstring."
                          ((ignore a) (ignore b))
                          ((ignore c) (ignore d)))))

    (should (equal (cl-letf (((symbol-function
                               'erc--prepare-custom-module-type)
                              #'symbol-name))
                     (macroexpand global-module))
                   `(progn

                      (define-minor-mode erc-mname-mode
                        "Toggle ERC mname mode.
With a prefix argument ARG, enable mname if ARG is positive, and
disable it otherwise.  If called from Lisp, enable the mode if
ARG is omitted or nil.

Some docstring."
                        :global t
                        :group (erc--find-group 'mname 'malias)
                        :require 'nil
                        :type "mname"
                        (let ((erc--module-toggle-prefix-arg arg))
                          (if erc-mname-mode
                              (erc-mname-enable)
                            (erc-mname-disable))))

                      (defun erc-mname-enable ()
                        "Enable ERC mname mode."
                        (interactive)
                        (unless (or erc--inside-mode-toggle-p
                                    (memq 'mname erc-modules))
                          (let ((erc--inside-mode-toggle-p t))
                            (erc--favor-changed-reverted-modules-state
                             'mname #'cons)))
                        (setq erc-mname-mode t)
                        (ignore a) (ignore b))

                      (defun erc-mname-disable ()
                        "Disable ERC mname mode."
                        (interactive)
                        (unless (or erc--inside-mode-toggle-p
                                    (not (memq 'mname erc-modules)))
                          (let ((erc--inside-mode-toggle-p t))
                            (erc--favor-changed-reverted-modules-state
                             'mname #'delq)))
                        (setq erc-mname-mode nil)
                        (ignore c) (ignore d))

                      (defalias 'erc-malias-mode #'erc-mname-mode)
                      (put 'erc-malias-mode 'erc-module 'mname)

                      (put 'erc-mname-mode 'erc-module 'mname)
                      (put 'erc-mname-mode 'definition-name 'mname)
                      (put 'erc-mname-enable 'definition-name 'mname)
                      (put 'erc-mname-disable 'definition-name 'mname))))))

(ert-deftest define-erc-module--local ()
  (let* ((global-module '(define-erc-module mname nil ; no alias
                           "Some docstring."
                           ((ignore a) (ignore b))
                           ((ignore c) (ignore d))
                           'local))
         (got (macroexpand global-module))
         (arg-en (cadr (nth 2 (nth 2 got))))
         (arg-dis (cadr (nth 2 (nth 3 got)))))

    (should (equal got
                   `(progn
                      (define-minor-mode erc-mname-mode
                        "Toggle ERC mname mode.
With a prefix argument ARG, enable mname if ARG is positive, and
disable it otherwise.  If called from Lisp, enable the mode if
ARG is omitted or nil.

Some docstring."
                        :global nil
                        :group (erc--find-group 'mname nil)
                        (let ((erc--module-toggle-prefix-arg arg))
                          (if erc-mname-mode
                              (erc-mname-enable)
                            (erc-mname-disable))))

                      (defun erc-mname-enable (&optional ,arg-en)
                        "Enable ERC mname mode.
When called interactively, do so in all buffers for the current
connection."
                        (interactive "p")
                        (when (derived-mode-p 'erc-mode)
                          (if ,arg-en
                              (erc-with-all-buffers-of-server
                                  erc-server-process nil
                                (erc-mname-enable))
                            (setq erc-mname-mode t)
                            (ignore a) (ignore b))))

                      (defun erc-mname-disable (&optional ,arg-dis)
                        "Disable ERC mname mode.
When called interactively, do so in all buffers for the current
connection."
                        (interactive "p")
                        (when (derived-mode-p 'erc-mode)
                          (if ,arg-dis
                              (erc-with-all-buffers-of-server
                                  erc-server-process nil
                                (erc-mname-disable))
                            (setq erc-mname-mode nil)
                            (ignore c) (ignore d))))

                      (put 'erc-mname-mode 'erc-module 'mname)
                      (put 'erc-mname-mode 'definition-name 'mname)
                      (put 'erc-mname-enable 'definition-name 'mname)
                      (put 'erc-mname-disable 'definition-name 'mname))))))

;;; erc-tests.el ends here