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

;; Copyright (C) 2015-2025 Free Software Foundation, Inc.

;; Author: Nicolas Richard <youngfrog@members.fsf.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)
(require 'cl-lib)

(ert-deftest cl-union-test-00 ()
  "Test for bug#22729."
  (let ((str1 "foo")
        (str2 (make-string 3 ?o)))
    ;; Emacs may make two string literals eql when reading.
    (aset str2 0 ?f)
    (should (not (eql str1 str2)))
    (should (equal str1 str2))
    (should (equal (cl-union (list str1) (list str2))
                   (list str2)))
    (should (equal (cl-union (list str1) (list str2) :test #'eql)
                   (list str1 str2)))))

(defmacro cl-seq-tests--relet* (binders &rest body)
  "Like `let*', but reevaluate BINDERS before each form in BODY.
Additionally register an `ert-info' to help identify test failures."
  (declare (debug let) (indent 1))
  (let ((syms (mapcar (lambda (binder)
                        (if (consp binder) (car binder) binder))
                      binders)))
    (macroexp-progn
     (mapcar (lambda (form)
               `(ert-info (,(lambda () (pp-to-string form)) :prefix "form: ")
                  (let* ,binders
                    ,@(and syms `((ignore ,@syms)))
                    ,form)))
             body))))

(ert-deftest cl-seq-endp-test ()
  (should (cl-endp '()))
  (should-not (cl-endp '(1)))
  (should-not (cl-endp '(1 2 3)))
  (should-error (cl-endp 1) :type 'wrong-type-argument)
  (should-error (cl-endp [1]) :type 'wrong-type-argument))

(ert-deftest cl-seq-reduce-test ()
  (should (equal 6 (cl-reduce #'+ '(1 2 3))))
  (should (equal 5 (cl-reduce #'+ '(1 2 3 4) :start 1 :end 3)))
  (should (equal 10 (cl-reduce #'+ '(1 2 3 4) :from-end t)))
  (should (equal 10 (cl-reduce #'+ '(1 2 3 4) :initial-value 0)))
  (should (equal 24 (cl-reduce #'* '(1 2 3 4) :initial-value 1)))
  (should (equal 0 (cl-reduce #'+ '())))
  (should (equal 0 (cl-reduce #'+ '() :initial-value 0)))
  (should (equal 1 (cl-reduce #'+ '(1))))
  (should (equal 0 (cl-reduce #'+ '() :initial-value 0))))

;; keywords supported:  :start :end
(ert-deftest cl-seq-fill-test ()
  (cl-seq-tests--relet* ((l (list 1 2 3 4 5 2 6))
                         (orig (copy-sequence l)))
    (should (equal '(b b b b b b b) (cl-fill l 'b)))
    (should (equal '(1 2 3 4 b b b) (cl-fill l 'b :start 4)))
    (should (equal '(b b b b 5 2 6) (cl-fill l 'b :end 4)))
    (should (equal '(1 2 b b 5 2 6) (cl-fill l 'b :start 2 :end 4)))
    (should (equal orig (cl-fill l 'b :end 0)))))

;; keywords supported:  :start1 :end1 :start2 :end2
(ert-deftest cl-seq-replace-test ()
  (cl-seq-tests--relet* ((l1 (list 1 2 3 4 5 2 6))
                         (l2 (make-list 6 'a))
                         (orig1 (copy-sequence l1)))
    (should (equal '(a a a a a a 6) (cl-replace l1 l2)))
    (should (equal '(a a a a a a 6) (cl-replace l1 l2 :start1 0)))
    (should (equal '(a a a a a a 6) (cl-replace l1 l2 :start2 0)))
    (should (equal orig1 (cl-replace l1 l2 :start1 (length l1))))
    (should (equal orig1 (cl-replace l1 l2 :start2 (length l2))))
    (should (equal orig1 (cl-replace l1 l2 :end1 0)))
    (should (equal orig1 (cl-replace l1 l2 :end2 0)))
    (should (equal '(1 2 3 4 a a a) (cl-replace l1 l2 :start1 4)))
    (should (equal '(a a a a 5 2 6) (cl-replace l1 l2 :end1 4)))
    (should (equal '(a a 3 4 5 2 6) (cl-replace l1 l2 :start2 4)))
    (should (equal '(a a a a 5 2 6) (cl-replace l1 l2 :end2 4)))
    (should (equal '(1 2 a a 5 2 6) (cl-replace l1 l2 :start1 2 :end1 4)))
    (should (equal '(a a 3 4 5 2 6) (cl-replace l1 l2 :start2 2 :end2 4)))))

(ert-deftest cl-lib-test-remove ()
  (let ((list (list 'a 'b 'c 'd))
        (key-index 0)
        (test-index 0))
    (let ((result
           (cl-remove 'foo list
                      :key (lambda (x)
                             (should (eql x (nth key-index list)))
                             (prog1
                                 (list key-index x)
                               (incf key-index)))
                      :test
                      (lambda (a b)
                        (should (eql a 'foo))
                        (should (equal b (list test-index
                                               (nth test-index list))))
                        (incf test-index)
                        (member test-index '(2 3))))))
      (should (equal key-index 4))
      (should (equal test-index 4))
      (should (equal result '(a d)))
      (should (equal list '(a b c d)))))
  (let ((x (cons nil nil))
        (y (cons nil nil)))
    (should (equal (cl-remove x (list x y))
                   ;; or (list x), since we use `equal' -- the
                   ;; important thing is that only one element got
                   ;; removed, this proves that the default test is
                   ;; `eql', not `equal'
                   (list y)))))

;; keywords supported:  :test :test-not :key :count :start :end :from-end
(ert-deftest cl-seq-remove-test ()
  (let ((list '(1 2 3 4 5 2 6)))
    (should (equal list (cl-remove 'foo list)))
    (should (equal '(1 3 4 5 6)   (cl-remove 2 list)))
    (should (equal '(1 3 4 5 6)   (cl-remove 2 list :key #'identity :test #'eql)))
    (should (equal '(1 2 3 4 2)   (cl-remove 4 list :test (lambda (a b) (> b a)))))
    (should (equal '(5 6)         (cl-remove 4 list :test-not (lambda (a b) (> b a)))))
    (should (equal '(1 3 5)       (cl-remove 'foo list :if #'evenp)))
    (should (equal '(2 4 2 6)     (cl-remove 'foo list :if-not #'evenp)))
    (should (equal '(1 2 3 4 5)   (cl-remove 'foo list :if #'evenp :start 4)))
    (should (equal '(1 2 3 4 5 6) (cl-remove 2 list :start 5 :end 6)))
    (should (equal '(1 3 4 5 2 6) (cl-remove 2 list :count 1)))
    (should (equal '(1 3 4 5 2 6) (cl-remove 2 list :from-end nil :count 1)))
    (should (equal '(1 2 3 4 5 6) (cl-remove 2 list :from-end t :count 1)))))

(ert-deftest cl-remove-if-test ()
  (should (equal '(1 3) (cl-remove-if #'evenp '(1 2 3 4))))
  (should (equal '(1 3) (cl-remove-if #'evenp '(1 2 3 4) :count 2)))
  (should (equal '(1 3 4) (cl-remove-if #'evenp '(1 2 3 4) :start 1 :end 3)))
  (should (equal '(1 3) (cl-remove-if #'evenp '(1 2 3 4) :from-end t)))
  (should (equal '(2 4) (cl-remove-if #'oddp '(1 2 3 4))))
  (should (equal '() (cl-remove-if #'evenp '())))
  (should (equal '() (cl-remove-if #'evenp '(2)))))

(ert-deftest cl-lib-test-remove-if-not ()
  (let ((list (list 'a 'b 'c 'd))
        (i 0))
    (let ((result (cl-remove-if-not (lambda (x)
                                      (should (eql x (nth i list)))
                                      (incf i)
                                      (member i '(2 3)))
                                    list)))
      (should (equal i 4))
      (should (equal result '(b c)))
      (should (equal list '(a b c d)))))
  (should (equal '()
                 (cl-remove-if-not (lambda (_x) (should nil)) '()))))

(ert-deftest cl-remove-if-not-test ()
  (should (equal '(2 4) (cl-remove-if-not #'evenp '(1 2 3 4))))
  (should (equal '(2 4) (cl-remove-if-not #'evenp '(1 2 3 4) :count 2)))
  (should (equal '(1 2 4) (cl-remove-if-not #'evenp '(1 2 3 4) :start 1 :end 3)))
  (should (equal '(2 4) (cl-remove-if-not #'evenp '(1 2 3 4) :from-end t)))
  (should (equal '(1 3) (cl-remove-if-not #'oddp '(1 2 3 4))))
  (should (equal '() (cl-remove-if-not #'evenp '())))
  (should (equal '(2) (cl-remove-if-not #'evenp '(2))))
  (should (equal '(2) (cl-remove-if-not #'evenp '(2) :key #'-))))

;; keywords supported:  :test :test-not :key :count :start :end :from-end
(ert-deftest cl-seq-delete-test ()
  (cl-seq-tests--relet* ((l (list 1 2 3 4 5 2 6))
                         (orig (copy-sequence l)))
    (should (equal orig           (cl-delete 'foo l)))
    (should (equal '(1 3 4 5 6)   (cl-delete 2 l)))
    (should (equal '(1 3 4 5 6)   (cl-delete 2 l :key #'identity :test #'eql)))
    (should (equal '(1 2 3 4 2)   (cl-delete 4 l :test (lambda (a b) (> b a)))))
    (should (equal '(5 6)         (cl-delete 4 l :test-not (lambda (a b) (> b a)))))
    (should (equal '(1 3 5)       (cl-delete 'foo l :if #'evenp)))
    (should (equal '(2 4 2 6)     (cl-delete 'foo l :if-not #'evenp)))
    (should (equal '(1 2 3 4 5)   (cl-delete 'foo l :if #'evenp :start 4)))
    (should (equal '(1 2 3 4 5 6) (cl-delete 2 l :start 5 :end 6)))
    (should (equal '(1 3 4 5 2 6) (cl-delete 2 l :count 1)))
    (should (equal '(1 3 4 5 2 6) (cl-delete 2 l :from-end nil :count 1)))
    (should (equal '(1 2 3 4 5 6) (cl-delete 2 l :from-end t :count 1)))))

(ert-deftest cl-delete-if-test ()
  (cl-seq-tests--relet* ((l (list 1 2 3 4 5)))
    (should (equal '(1 3 5) (cl-delete-if #'evenp l)))
    (should (equal '(1 3 5) (cl-delete-if #'evenp l :start 0 :end 4)))
    (should (equal '(1 3 5) (cl-delete-if #'evenp l :from-end t)))
    (should (equal '(2 4) (cl-delete-if #'oddp l))))
  (should (equal '() (cl-delete-if #'evenp '())))
  (should (equal '() (cl-delete-if #'evenp (list 2)))))

(ert-deftest cl-delete-if-not-test ()
  (should (equal '(2 4) (cl-delete-if-not #'evenp (list 1 2 3 4 5))))
  (should (equal '() (cl-delete-if-not #'evenp '())))
  (should (equal '() (cl-delete-if-not #'evenp (list 1)))))

(ert-deftest cl-delete-duplicates-test ()
  (should (equal '(3 2 1) (cl-delete-duplicates (list 1 2 3 2 1))))
  (should (equal '() (cl-delete-duplicates '()))))

;; keywords supported:  :test :test-not :key :start :end :from-end
(ert-deftest cl-seq-remove-duplicates-test ()
  (let ((list '(1 2 3 4 5 2 6)))
    (should (equal '(1 3 4 5 2 6) (cl-remove-duplicates list)))
    (should (equal '(1 2 3 4 5 6) (cl-remove-duplicates list :from-end t)))
    (should (equal list           (cl-remove-duplicates list :start 2)))
    (should (equal list           (cl-remove-duplicates list :start 2 :from-end t)))
    (should (equal list           (cl-remove-duplicates list :end 4)))
    (should (equal '(6)           (cl-remove-duplicates list :test #'<)))
    (should (equal '(1 2 6)       (cl-remove-duplicates list :test #'>=)))
    (should (equal (cl-remove-duplicates list :test #'>=)
                   (cl-remove-duplicates list :test-not #'<)))
    (should (equal (cl-remove-duplicates list)
                   (cl-remove-duplicates list :key #'number-to-string :test #'string=)))
    (should (equal list
                   (cl-remove-duplicates list :key #'number-to-string :test #'eq)))))

;; keywords supported:  :test :test-not :key :count :start :end :from-end
(ert-deftest cl-seq-substitute-test ()
  (let ((list '(1 2 3 4 5 2 6)))
    (should (equal '(1 b 3 4 5 b 6) (cl-substitute 'b 2 list)))
    (should (equal list (cl-substitute 'b 2 list :start (length list))))
    (should (equal list (cl-substitute 'b 2 list :end 0)))
    (should (equal '(1 2 3 4 5 b 6) (cl-substitute 'b 2 list :start 2)))
    (should (equal '(1 b 3 4 5 2 6) (cl-substitute 'b 2 list :end 2)))
    (should (equal list (cl-substitute 'b 2 list :start 2 :end 4)))
    (should (equal '(1 b 3 4 5 2 6) (cl-substitute 'b 2 list :count 1)))
    (should (equal '(1 2 3 4 5 b 6) (cl-substitute 'b 2 list :count 1 :from-end t)))
    (should (equal list             (cl-substitute 'b 2 list :count -1)))
    (should (equal '(1 b 3 4 5 b 6) (cl-substitute 'b "2" list
                                                   :key #'number-to-string
                                                   :test #'string=)))
    (should (equal (cl-substitute 'b 2 list)
                   (cl-substitute 'b 2 list :test #'eq)))
    (should (equal '(1 2 b b b 2 b) (cl-substitute 'b 2 list :test #'<)))
    (should (equal '(b b 3 4 5 b 6) (cl-substitute 'b 2 list :test #'>=)))
    (should (equal list             (cl-substitute 'b 99 list :test #'<)))
    (should (equal (cl-substitute 'b 2 list :test #'>=)
                   (cl-substitute 'b 2 list :test-not #'<)))
    (let ((pred (lambda (x) (> (cl-position x list) 1))))
      (should (equal '(1 2 b b b 2 b) (cl-substitute 'b nil list :if pred))))
    (let ((pred (lambda (x) (> (cl-position x list :from-end t) 1))))
      (should (equal '(1 b b b b b b) (cl-substitute 'b nil list :if pred))))
    (let ((pred (lambda (x) (> (cl-position x list) 1))))
      (should (equal '(b b 3 4 5 b 6) (cl-substitute 'b nil list :if-not pred))))
    (let ((pred (lambda (x) (> (cl-position x list :from-end t) 1))))
      (should (equal '(b 2 3 4 5 2 6) (cl-substitute 'b nil list :if-not pred))))))

(ert-deftest cl-seq-substitute-if-test ()
  (let ((result (cl-substitute-if 'x #'evenp '(1 2 3 4 5))))
    (should (equal result '(1 x 3 x 5))))
  (let ((result (cl-substitute-if 'x #'evenp '(1 3 5))))
    (should (equal result '(1 3 5))))
  (let ((result (cl-substitute-if 'x #'always '(1 2 3 4 5))))
    (should (equal result '(x x x x x))))
  (let ((result (cl-substitute-if 'x #'evenp '(1 2 3 4 5) :start 1 :end 4)))
    (should (equal result '(1 x 3 x 5))))
  (let ((result (cl-substitute-if 'x #'oddp '(1 2 3 4 5) :from-end t)))
    (should (equal result '(x 2 x 4 x))))
  (let ((result (cl-substitute-if 'x (lambda (n) (= n 3)) '(1 2 3 4 5)
                                  :key #'identity)))
    (should (equal result '(1 2 x 4 5)))))

(ert-deftest cl-seq-substitute-if-not-test ()
  (let ((result (cl-substitute-if-not 'x #'evenp '(1 2 3 4 5))))
    (should (equal result '(x 2 x 4 x))))
  (let ((result (cl-substitute-if-not 'x #'evenp '(2 4 6))))
    (should (equal result '(2 4 6))))
  (let ((result (cl-substitute-if-not 'x (lambda (n) (> n 5)) '(1 2 3 4 5))))
    (should (equal result '(x x x x x))))
  (let ((result (cl-substitute-if-not 'x #'evenp '(1 2 3 4 5) :start 0 :end 4)))
    (should (equal result '(x 2 x 4 5))))
  (let ((result (cl-substitute-if-not 'x #'oddp '(1 2 3 4 5) :from-end t)))
    (should (equal result '(1 x 3 x 5))))
  (let ((result (cl-substitute-if-not 'x (lambda (n) (= n 3)) '(1 2 3 4 5)
                                      :key #'identity)))
    (should (equal result '(x x 3 x x)))))

(ert-deftest cl-find-if-test ()
  (let ((result (cl-find-if #'evenp '(1 2 3 4 5))))
    (should (equal result 2)))
  (let ((result (cl-find-if (lambda (n) (> n 5)) '(1 2 3 4 5))))
    (should (equal result nil)))
  (let ((result (cl-find-if (lambda (n) (> n 3)) '(1 2 3 4 5 6 7))))
    (should (equal result 4)))
  (let ((result (cl-find-if #'evenp '(1 2 3 4 5) :start 2)))
    (should (equal result 4)))
  (let ((result (cl-find-if #'evenp '(1 2 3 4 5) :end 1)))
    (should (equal result nil)))
  (let ((result (cl-find-if #'oddp '(2 4 5 6 7) :from-end t)))
    (should (equal result 7)))
  (let ((result (cl-find-if (lambda (n) (= n 4)) '(1 2 3 4 5) :key #'identity)))
    (should (equal result 4))))

(ert-deftest cl-find-if-not-test ()
  (let ((result (cl-find-if-not #'evenp '(1 2 3 4 5))))
    (should (equal result 1)))
  (let ((result (cl-find-if-not #'oddp '(1 3 5))))
    (should (equal result nil)))
  (let ((result (cl-find-if-not (lambda (n) (< n 4)) '(1 2 3 4 5 6 7))))
    (should (equal result 4)))
  (let ((result (cl-find-if-not #'evenp '(1 2 3 4 5) :start 2)))
    (should (equal result 3)))
  (let ((result (cl-find-if-not #'evenp '(1 2 3 4 5) :end 3)))
    (should (equal result 1)))
  (let ((result (cl-find-if-not #'oddp '(2 4 6 7 8) :from-end t)))
    (should (equal result 8)))
  (let ((result (cl-find-if-not (lambda (n) (= n 4)) '(1 2 3 4 5) :key #'identity)))
    (should (equal result 1))))

;; keywords supported:  :test :test-not :key :count :start :end :from-end
(ert-deftest cl-seq-nsubstitute-test ()
  (cl-seq-tests--relet* ((l (list 1 2 3 4 5 2 6))
                         (orig (copy-sequence l)))
    (should (equal '(1 b 3 4 5 b 6) (cl-nsubstitute 'b 2 l)))
    (should (equal orig (cl-nsubstitute 'b 2 l :start (length l))))
    (should (equal orig (cl-nsubstitute 'b 2 l :end 0)))
    (should (equal '(1 2 3 4 5 b 6) (cl-nsubstitute 'b 2 l :start 2)))
    (should (equal '(1 b 3 4 5 2 6) (cl-nsubstitute 'b 2 l :end 2)))
    (should (equal orig (cl-nsubstitute 'b 2 l :start 2 :end 4)))
    (should (equal '(1 b 3 4 5 2 6) (cl-nsubstitute 'b 2 l :count 1)))
    (should (equal '(1 2 3 4 5 b 6) (cl-nsubstitute 'b 2 l :count 1 :from-end t)))
    (should (equal orig (cl-nsubstitute 'b 2 l :count -1)))
    (should (equal '(1 b 3 4 5 b 6) (cl-nsubstitute 'b "2" l
                                                    :key #'number-to-string
                                                    :test #'string=)))
    (should (equal (cl-nsubstitute 'b 2 orig)
                   (cl-nsubstitute 'b 2 l :test #'eq)))
    (should (equal '(1 2 b b b 2 b) (cl-nsubstitute 'b 2 l :test #'<)))
    (should (equal '(b b 3 4 5 b 6) (cl-nsubstitute 'b 2 l :test #'>=)))
    (should (equal orig (cl-nsubstitute 'b 99 l :test #'<)))
    (should (equal (cl-nsubstitute 'b 2 orig :test #'>=)
                   (cl-nsubstitute 'b 2 l :test-not #'<)))
    (let ((pred (lambda (x) (> (cl-position x orig) 1))))
      (should (equal '(1 2 b b b 2 b) (cl-nsubstitute 'b nil l :if pred))))
    (let ((pred (lambda (x) (> (cl-position x orig :from-end t) 1))))
      (should (equal '(1 b b b b b b) (cl-nsubstitute 'b nil l :if pred))))
    (let ((pred (lambda (x) (> (cl-position x orig) 1))))
      (should (equal '(b b 3 4 5 b 6) (cl-nsubstitute 'b nil l :if-not pred))))
    (let ((pred (lambda (x) (> (cl-position x orig :from-end t) 1))))
      (should (equal '(b 2 3 4 5 2 6) (cl-nsubstitute 'b nil l :if-not pred))))))

(ert-deftest cl-lib-test-string-position ()
  (should (eql (cl-position ?x "") nil))
  (should (eql (cl-position ?a "abc") 0))
  (should (eql (cl-position ?b "abc") 1))
  (should (eql (cl-position ?c "abc") 2))
  (should (eql (cl-position ?d "abc") nil))
  (should (eql (cl-position ?A "abc") nil)))

;; keywords supported:  :test :test-not :key :start :end :from-end
(ert-deftest cl-seq-position-test ()
  (let ((list '(1 2 3 4 5 2 6)))
    (should-not (cl-position 'foo list))
    (should (= 1 (cl-position 2 list)))
    (should (= 5 (cl-position 2 list :start 5 :end 6)))
    (should (= 1 (cl-position 2 list :from-end nil)))
    (should (= 5 (cl-position 2 list :from-end t)))
    (should (cl-position 2 list :key #'identity :test #'eql))
    (should (= 1 (cl-position "2" list :key #'number-to-string :test #'string=)))
    (should (= 5 (cl-position "2" list :key #'number-to-string
                              :test #'string= :from-end t)))
    (should-not (cl-position "2" list :key #'number-to-string))
    (should (cl-position 5 list :key (lambda (x) (1+ (* 1.0 x x))) :test #'=))
    (should-not (cl-position 5 list :key (lambda (x) (1+ (* 1.0 x x)))))
    (should (= 1 (cl-position 5 list :key (lambda (x) (1+ (* x x))))))
    (should (= 5 (cl-position 5 list :key (lambda (x) (1+ (* x x))) :from-end t)))))

(ert-deftest cl-position-if-test ()
  (let ((result (cl-position-if #'evenp '(1 2 3 4 5))))
    (should (equal result 1)))
  (let ((result (cl-position-if (lambda (n) (> n 5)) '(1 2 3 4 5))))
    (should (equal result nil)))
  (let ((result (cl-position-if (lambda (n) (> n 3)) '(1 2 3 4 5 6 7))))
    (should (equal result 3)))
  (let ((result (cl-position-if #'evenp '(1 2 3 4 5) :start 2)))
    (should (equal result 3)))
  (let ((result (cl-position-if #'evenp '(1 2 3 4 5) :end 1)))
    (should (equal result nil)))
  (let ((result (cl-position-if #'oddp '(2 4 5 6 7) :from-end t)))
    (should (equal result 4)))
  (let ((result (cl-position-if (lambda (n) (= n 4)) '(1 2 3 4 5) :key #'identity)))
    (should (equal result 3))))

;; keywords supported:  :test :test-not :key :start :end
(ert-deftest cl-seq-count-test ()
  (let ((list '(1 2 3 4 5 2 6)))
    (should (= 2 (cl-count 2 list)))
    (should (= 1 (cl-count 2 list :start 2)))
    (should (= 1 (cl-count 2 list :end 4)))
    (should (= 0 (cl-count -5 list)))
    (should (= 0 (cl-count 2 list :start 2 :end 4)))
    (should (= 4 (cl-count 'foo list :key (lambda (x) (and (evenp x) 'foo)))))
    (should (= 4 (cl-count 'foo list :test (lambda (_a b) (evenp b)))))
    (should (equal (cl-count 'foo list :test (lambda (_a b) (oddp b)))
                   (cl-count 'foo list :test-not (lambda (_a b) (evenp b)))))))

(ert-deftest cl-count-if-test ()
  (let ((result (cl-count-if #'evenp '(1 2 3 4 5))))
    (should (equal result 2)))
  (let ((result (cl-count-if #'oddp '(2 4 6 8))))
    (should (equal result 0)))
  (let ((result (cl-count-if #'always '(1 2 3 4))))
    (should (equal result 4)))
  (let ((result (cl-count-if #'ignore '(1 2 3 4))))
    (should (equal result 0)))
  (let ((result (cl-count-if (lambda (x) (> x 2)) '(1 2 3 4 5) :key #'identity)))
    (should (equal result 3)))
  (let ((result (cl-count-if #'evenp '(1 2 3 4 5) :start 2)))
    (should (equal result 1)))
  (let ((result (cl-count-if #'evenp '(1 2 3 4 5) :end 3)))
    (should (equal result 1)))
  (let ((result (cl-count-if #'evenp '())))
    (should (equal result 0)))
  (let ((result (cl-count-if #'numberp '(1 "two" 3 4 "five" 6))))
    (should (equal result 4)))
  (let ((result (cl-count-if (lambda (x) (and (numberp x) (> x 2))) '(1 2 3 4 5 6))))
    (should (equal result 4))))

(ert-deftest cl-count-if-not-test ()
  (let ((result (cl-count-if-not #'evenp '(1 2 3 4 5))))
    (should (equal result 3)))
  (let ((result (cl-count-if-not #'oddp '(1 3 5))))
    (should (equal result 0)))
  (let ((result (cl-count-if-not #'always '(1 2 3 4))))
    (should (equal result 0)))
  (let ((result (cl-count-if-not #'ignore '(1 2 3 4))))
    (should (equal result 4)))
  (let ((result (cl-count-if-not (lambda (x) (> x 3)) '(1 2 3 4 5) :key #'identity)))
    (should (equal result 3)))
  (let ((result (cl-count-if-not #'evenp '(1 2 3 4 5) :start 2)))
    (should (equal result 2)))
  (let ((result (cl-count-if-not #'evenp '(1 2 3 4 5) :end 3)))
    (should (equal result 2)))
  (let ((result (cl-count-if-not #'evenp '())))
    (should (equal result 0)))
  (let ((result (cl-count-if-not #'numberp '(1 "two" 3 4 "five" 6))))
    (should (equal result 2)))
  (let ((result (cl-count-if-not (lambda (x) (and (numberp x) (> x 2)))
                                 '(1 2 3 4 5 6))))
    (should (equal result 2))))

(ert-deftest cl-lib-test-mismatch ()
  (should (eql (cl-mismatch "" "") nil))
  (should (eql (cl-mismatch "" "a") 0))
  (should (eql (cl-mismatch "a" "a") nil))
  (should (eql (cl-mismatch "ab" "a") 1))
  (should (eql (cl-mismatch "Aa" "aA") 0))
  (should (eql (cl-mismatch '(a b c) '(a b d)) 2)))

;; keywords supported:  :test :test-not :key :start1 :end1 :start2 :end2 :from-end
(ert-deftest cl-seq-mismatch-test ()
  (let ((list '(1 2 3 4 5 2 6))
        (list2 '(1 999 2 3 4 5 2 6)))
    (should-not (cl-mismatch list list))
    (should-not (cl-mismatch list (remove 999 list2)))
    (should (= 0 (cl-mismatch list list :key #'number-to-string)))
    (should-not (cl-mismatch list list :key #'number-to-string :test #'string=))
    (should (= 1 (cl-mismatch list list2)))
    (should (= 0 (cl-mismatch list list2 :from-end t)))
    (should (= 3 (cl-mismatch '(1 2 3) list)))
    (should-not (cl-mismatch list list2 :end1 1 :end2 1))
    (should-not (cl-mismatch list list2 :start1 1 :start2 2))
    (should (= 1 (cl-mismatch list list2 :start1 1 :end1 2 :start2 4 :end2 4)))
    (should (= -1 (cl-mismatch list list2 :from-end t :key #'number-to-string
                               :test (lambda (a b)
                                       (and (stringp a) (stringp b))))))
    (should (= 7 (cl-mismatch list list2 :key #'number-to-string
                              :test (lambda (a b)
                                      (and (stringp a) (stringp b))))))))

;; keywords supported:  :test :test-not :key :start1 :end1 :start2 :end2 :from-end
(ert-deftest cl-seq-search-test ()
  (let ((list '(1 2 3 4 5 2 6))
        (list2 '(1 999 2 3 4 5 2 6)))
    (should-not (cl-search list list2))
    (should (= 2 (cl-search list list2 :start1 1 :start2 2)))
    (should (= 4 (cl-search list list2 :start1 3)))
    (should (= 6 (cl-search list list2 :start1 5)))
    (should (= 0 (cl-search list list2 :end1 1)))
    (should (= 0 (cl-search nil list2)))
    (should (= 2 (cl-search list list2 :start1 1 :end1 2 :end2 3)))
    (should (= 0 (cl-search list list2 :test (lambda (a b)
                                               (and (numberp a) (numberp b))))))
    (should (= 0 (cl-search list list2 :key (lambda (x) (and (numberp x) 'foo))
                            :test (lambda (a b) (and (eq a 'foo) (eq b 'foo))))))
    (should (= 1 (cl-search (nthcdr 2 list) (nthcdr 2 list2))))
    (should (= 3 (cl-search (nthcdr 2 list) list2)))))

(ert-deftest cl-seq-test-bug24264 ()
  "Test for bug#24264."
  :tags '(:expensive-test)
  (let ((list  (nconc (make-list 8000005 1) '(8)))
        (list2 (make-list 8000005 2)))
    (should (cl-position 8 list))
    (should-not (equal '(8) (last (cl-remove 8 list))))
    (should (equal '(2 8) (last (cl-substitute 2 1 list) 2)))
    (should (equal '(2 8) (last (cl-replace list list2) 2)))
    (should (equal '(1 1) (last (cl-fill list 1) 2)))))

(ert-deftest cl-seq-bignum-eql ()
  (let ((x (+ most-positive-fixnum 1))
        (y (+ most-positive-fixnum 1)))
    (let ((l (list y)))
      (should (eq (cl-member x l) l)))
    (let ((a (list (cons y 1) (cons 2 y))))
      (should (eq (cl-assoc x a) (car a)))
      (should (eq (cl-rassoc x a) (cadr a))))))

(ert-deftest cl-sort-test ()
  (let ((result (cl-sort (list 3 1 4 1 5 9 2 6 5 3 5) #'<)))
    (should (equal result '(1 1 2 3 3 4 5 5 5 6 9))))
  (let ((result (cl-sort (list 5 3 2 8 1 4) #'>)))
    (should (equal result '(8 5 4 3 2 1))))
  (let ((result (cl-sort (list "banana" "apple" "cherry") #'string<)))
    (should (equal result '("apple" "banana" "cherry"))))
  (let ((result (cl-sort (list "banana" "fig" "apple" "kiwi")
                         (lambda (x y) (length< x (length y)))
                         :key #'identity)))
    (should (equal result '("fig" "kiwi" "apple" "banana"))))
  (let ((result (cl-sort (vector 3 1 4 1 5) #'<)))
    (should (equal result [1 1 3 4 5])))
  (let ((result (cl-sort (list 1 2 3 4 5) #'<)))
    (should (equal result '(1 2 3 4 5))))
  (let ((result (cl-sort (list -3 1 4 -1 -5 9) #'<)))
    (should (equal result '(-5 -3 -1 1 4 9))))
  (let ((result (cl-sort (list 1 2 3 4 5) #'>)))
    (should (equal result '(5 4 3 2 1))))
  (let ((result (cl-sort '() #'<)))
    (should (equal result '())))
  (let ((result (cl-sort (list "Banana" "apple" "cherry")
                         #'string< :key #'downcase)))
    (should (equal result '("apple" "Banana" "cherry")))) )

(ert-deftest cl-stable-sort-test ()
  (let ((result (cl-stable-sort (list 3 1 4 1 5 9 2 6 5 3 5) #'<)))
    (should (equal result '(1 1 2 3 3 4 5 5 5 6 9))))
  (let ((result (cl-stable-sort (list 5 3 2 8 1 4) #'>)))
    (should (equal result '(8 5 4 3 2 1))))
  (let ((result (cl-stable-sort (list "banana" "apple" "cherry") #'string<)))
    (should (equal result '("apple" "banana" "cherry"))))
  (let ((result (cl-stable-sort (list "banana" "fig" "apple" "kiwi")
                                (lambda (x y) (length< x (length y)))
                                :key #'identity)))
    (should (equal result '("fig" "kiwi" "apple" "banana"))))
  (let ((result (cl-stable-sort (vector 3 1 4 1 5) #'<)))
    (should (equal result [1 1 3 4 5])))
  (let ((result (cl-stable-sort (list 1 2 3 4 5) #'<)))
    (should (equal result '(1 2 3 4 5))))
  (let ((result (cl-stable-sort (list -3 1 4 -1 -5 9) #'<)))
    (should (equal result '(-5 -3 -1 1 4 9))))
  (let ((result (cl-stable-sort (list 1 2 3 4 5) #'>)))
    (should (equal result '(5 4 3 2 1))))
  (let ((result (cl-stable-sort '() #'<)))
    (should (equal result '())))
  (let ((result (cl-stable-sort (list "Banana" "apple" "cherry")
                                #'string< :key #'downcase)))
    (should (equal result '("apple" "Banana" "cherry")))) )

(ert-deftest cl-merge-test ()
  (let ((result (cl-merge 'list (list 1 3 5) (list 2 4 6) #'<)))
    (should (equal result '(1 2 3 4 5 6))))
  (let ((result (cl-merge 'list (list 1 3 3 5) (list 2 3 4 6) #'<)))
    (should (equal result '(1 2 3 3 3 4 5 6))))
  (let ((result (cl-merge 'list '() (list 2 4 6) #'<)))
    (should (equal result '(2 4 6))))
  (let ((result (cl-merge 'list (list 1 3 5) '() #'<)))
    (should (equal result '(1 3 5))))
  (let ((result (cl-merge 'list '() '() #'<)))
    (should (equal result '())))
  (let ((result (cl-merge 'list (list 1 4 6) (list 2 3 5) #'< :key #'identity)))
    (should (equal result '(1 2 3 4 5 6))))
  (let ((result (cl-merge 'vector (vector 1 3 5) (vector 2 4 6) #'<)))
    (should (equal result [1 2 3 4 5 6])))
  (let ((result (cl-merge 'list (list 5 3 1) (list 6 4 2) #'>)))
    (should (equal result '(6 5 4 3 2 1))))
  (let ((result (cl-merge 'list (list 1 2 3) (list 1 2 3) #'>)))
    (should (equal result '(1 2 3 1 2 3))))
  (let ((result (cl-merge 'list (list 1 2) (list 3 4 5) #'<)))
    (should (equal result '(1 2 3 4 5))))
  (let ((result (cl-merge 'list (list 4 5 6) (list 1 2 3) #'<)))
    (should (equal result '(1 2 3 4 5 6))))
  (let ((result (cl-merge 'list (list 1 2 3) (list 1.5 2.5 3.5) #'<)))
    (should (equal result '(1 1.5 2 2.5 3 3.5))))
  (let ((result (cl-merge 'list (list 1 2 3) (list 10 20 30)
                          #'< :key (lambda (x) (* x 10)))))
    (should (equal result '(1 2 3 10 20 30)))))

(ert-deftest cl-member-test ()
  (let ((result (cl-member 'b '(a b c d))))
    (should (equal result '(b c d))))
  (let ((result (cl-member 'x '(a b c d))))
    (should (equal result nil)))
  (let ((result (cl-member 'a '(a b a c d))))
    (should (equal result '(a b a c d))))
  (let ((result (cl-member "test" '("test" "not-test" "test2") :test #'string=)))
    (should (equal result '("test" "not-test" "test2"))))
  (let ((result (cl-member 'x '(a b c d) :test-not #'eq)))
    (should (equal result '(a b c d))))
  (let ((result (cl-member 3 '(1 2 3 4 5) :key #'identity)))
    (should (equal result '(3 4 5))))
  (let ((result (cl-member 2.5 '(1 2 2.5 3) :test #'equal)))
    (should (equal result '(2.5 3))))
  (let ((result (cl-member 'a '(a a a a) :test #'eq)))
    (should (equal result '(a a a a))))
  (let ((result (cl-member 'a '())))
    (should (equal result nil)))
  (let ((result (cl-member 'b '(a c d) :test-not #'eq)))
    (should (equal result '(a c d))))
  (let ((result (cl-member 3 '(1 2 3 4 5) :key #'1+)))
    (should (equal result '(2 3 4 5)))))

(ert-deftest cl-member-if-test ()
  (let ((result (cl-member-if #'evenp '(1 2 3 4 5))))
    (should (equal result '(2 3 4 5))))
  (let ((result (cl-member-if #'ignore '(1 2 3 4 5))))
    (should (equal result nil)))
  (let ((result (cl-member-if #'always '(1 2 3 4 5))))
    (should (equal result '(1 2 3 4 5))))
  (let ((result (cl-member-if (lambda (x) (= x 1)) '(1 2 3 4 5))))
    (should (equal result '(1 2 3 4 5))))
  (let ((result (cl-member-if (lambda (x) (and (numberp x) (evenp x)))
                              '(1 3 5 4 2))))
    (should (equal result '(4 2))))
  (let ((result (cl-member-if (lambda (x) (string= (number-to-string x) "3"))
                              '(1 2 3 4 5) :key #'identity)))
    (should (equal result '(3 4 5))))
  (let ((result (cl-member-if (lambda (x) (eq x 'a)) '(a a a a))))
    (should (equal result '(a a a a))))
  (let ((result (cl-member-if #'evenp '())))
    (should (equal result nil)))
  (let ((result (cl-member-if #'minusp '(1 2 3 4 5))))
    (should (equal result nil)))
  (let ((result (cl-member-if (lambda (x) (and (numberp x) (<= x 2)))
                              '(1 "two" 3 0))))
    (should (equal result '(1 "two" 3 0))))
  (let ((result (cl-member-if (lambda (x) (> x 5)) '(1 2 3 6 7 8)
                              :key #'identity)))
    (should (equal result '(6 7 8)))))

(ert-deftest cl-member-if-not-test ()
  (let ((result (cl-member-if-not #'evenp '(1 2 3 4 5))))
    (should (equal result '(1 2 3 4 5))))
  (let ((result (cl-member-if-not #'evenp '(2 4 6 8 10 11))))
    (should (equal result '(11))))
  (let ((result (cl-member-if-not (lambda (x) (> x 5)) '(1 2 3 4 5))))
    (should (equal result '(1 2 3 4 5))))
  (let ((result (cl-member-if-not #'always '(1 2 3 4 5))))
    (should (equal result nil)))
  (let ((result (cl-member-if-not (lambda (x) (= x 1)) '(1 2 3 4 5))))
    (should (equal result '(2 3 4 5))))
  (let ((result (cl-member-if-not (lambda (x) (string= (number-to-string x) "2"))
                                  '(1 2 3 4 5) :key #'identity)))
    (should (equal result '(1 2 3 4 5))))
  (let ((result (cl-member-if-not #'evenp '())))
    (should (equal result nil)))
  (let ((result (cl-member-if-not (lambda (x) (eq x 'a)) '(a a a a))))
    (should (equal result nil)))
  (let ((result (cl-member-if-not #'minusp '(1 2 3 4 5))))
    (should (equal result '(1 2 3 4 5))))
  (let ((result (cl-member-if-not
                 (lambda (x) (or (numberp x) (stringp x) (eq x 'b)))
                 '(a "b" 3 nil))))
    (should (equal result '(a "b" 3 nil))))
  (let ((result (cl-member-if-not #'numberp '(1 "two" 3 "four" 5)
                                  :key #'identity)))
    (should (equal result '("two" 3 "four" 5)))))

(ert-deftest cl-assoc-test ()
  (let ((result (cl-assoc 'b '((a . 1) (b . 2) (c . 3)))))
    (should (equal result '(b . 2))))
  (let ((result (cl-assoc 'x '((a . 1) (b . 2) (c . 3)))))
    (should (equal result nil)))
  (let ((result (cl-assoc "key" '(("key" . 1) ("not-key" . 2)) :test #'string=)))
    (should (equal result '("key" . 1))))
  (let ((result (cl-assoc 'a '((a . 1) (b . 2) (c . 3)) :test-not #'eq)))
    (should (equal result '(b . 2))))
  (let ((result (cl-assoc '2 '((1 . 'a) (2 . 'b) (3 . 'c)) :key #'identity)))
    (should (equal result '(2 . 'b))))
  (let ((result (cl-assoc 'a '((a . 1) (a . 2) (a . 3)) :test #'eq)))
    (should (equal result '(a . 1))))
  (let ((result (cl-assoc 'a '())))
    (should (equal result nil)))
  (let ((result (cl-assoc 'b '((a . 1) (b . 2) (b . 3) (c . 4)))))
    (should (equal result '(b . 2)))))

(ert-deftest cl-assoc-if-test ()
  (let ((result (cl-assoc-if #'evenp
                             '((1 . "odd") (2 . "even") (3 . "odd") (4 . "even")))))
    (should (equal result '(2 . "even"))))
  (let ((result (cl-assoc-if (lambda (x) (= x 5))
                             '((1 . "one") (2 . "two") (3 . "three")))))
    (should (equal result nil)))
  (let ((result (cl-assoc-if (lambda (x) (= x 1))
                             '((1 . "one") (2 . "two") (3 . "three")))))
    (should (equal result '(1 . "one"))))
  (let ((result (cl-assoc-if (lambda (x) (string= x "baz"))
                             '((foo . 1) (bar . 2) (baz . 3)))))
    (should (equal result '(baz . 3))))
  (let ((result (cl-assoc-if (lambda (x) (and (numberp x) (> x 2)))
                             '((1 . "one") (3 . "three") (4 . "four")))))
    (should (equal result '(3 . "three"))))
  (let ((result (cl-assoc-if (lambda (x) (> x 1))
                             '((0 . "zero") (1 . "one") (2 . "two")))))
    (should (equal result '(2 . "two"))))
  (let ((result (cl-assoc-if #'evenp '())))
    (should (equal result nil)))
  (let ((result (cl-assoc-if (lambda (x) (eq x 'a))
                             '((a . "first") (a . "second") (b . "third")))))
    (should (equal result '(a . "first"))))
  (let ((result (cl-assoc-if (lambda (x) (and (symbolp x) (not (eq x 'b))))
                             '((b . "b") (c . "c") (d . "d")))))
    (should (equal result '(c . "c"))))
  (let ((result (cl-assoc-if #'cdr '(((1 2) . "pair 1") ((1) . "pair 2")))))
    (should (equal result '((1 2) . "pair 1")))))

(ert-deftest cl-assoc-if-not-test ()
  (let* ((alist '((1 . "odd") (2 . "even") (3 . "odd") (4 . "even")))
         (result (cl-assoc-if-not #'evenp alist)))
    (should (equal result '(1 . "odd"))))
  (let ((result (cl-assoc-if-not #'plusp
                                 '((1 . "one") (2 . "two") (3 . "three")))))
    (should (equal result nil)))
  (let ((result (cl-assoc-if-not (lambda (x) (< x 5))
                                 '((1 . "one") (2 . "two") (3 . "three")))))
    (should (equal result nil)))
  (let ((result (cl-assoc-if-not (lambda (x) (= x 1))
                                 '((1 . "one") (2 . "two") (3 . "three")))))
    (should (equal result '(2 . "two"))))
  (let ((result (cl-assoc-if-not
                 (lambda (x) (string= x "baz"))
                 '((foo . "first") (bar . "second") (baz . "third")))))
    (should (equal result '(foo . "first"))))
  (let ((result (cl-assoc-if-not (lambda (x) (and (numberp x) (> x 2)))
                                 '((1 . "one") (3 . "three") (4 . "four")))))
    (should (equal result '(1 . "one"))))
  (let ((result (cl-assoc-if-not #'symbolp
                                 '((1 . "one") (b . "bee") (2 . "two")))))
    (should (equal result '(1 . "one"))))
  (let ((result (cl-assoc-if-not #'evenp '())))
    (should (equal result nil)))
  (let ((result (cl-assoc-if-not (lambda (x) (eq x 'a))
                                 '((a . "first") (a . "second") (b . "third")))))
    (should (equal result '(b . "third")))))

(ert-deftest cl-rassoc-test ()
  (let ((result (cl-rassoc 2 '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result '("two" . 2))))
  (let ((result (cl-rassoc 4 '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result nil)))
  (let ((result (cl-rassoc 2 '(("one" . 1) ("two" . 2) ("baz" . 2))
                           :test #'equal)))
    (should (equal result '("two" . 2))))
  (let ((result (cl-rassoc 2 '(("one" . 1) ("two" . 2) ("three" . 3))
                           :test-not #'equal)))
    (should (equal result '("one" . 1))))
  (let ((result (cl-rassoc 1 '())))
    (should (equal result nil)))
  (let ((result (cl-rassoc 1 '(("first" . 1) ("second" . 1) ("third" . 1)))))
    (should (equal result '("first" . 1))))
  (let ((result (cl-rassoc 3 '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result '("three" . 3))))
  (let ((result (cl-rassoc 'found
                           '((("pair 1") . 1) ("pair 2" . 2) ("pair 3" . 3)))))
    (should (equal result nil))))

(ert-deftest cl-rassoc-if-test ()
  (let ((result (cl-rassoc-if #'evenp
                              '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result '("two" . 2))))
  (let ((result (cl-rassoc-if #'evenp
                              '(("one" . 1) ("three" . 3) ("five" . 5)))))
    (should (equal result nil)))
  (let ((result (cl-rassoc-if (lambda (x) (= x 1))
                              '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result '("one" . 1))))
  (let ((result (cl-rassoc-if (lambda (x) (> x 1))
                              '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result '("two" . 2))))
  (let ((result (cl-rassoc-if (lambda (x) (and (numberp x) (< x 3)))
                              '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result '("one" . 1))))
  (let ((result (cl-rassoc-if #'evenp '())))
    (should (equal result nil)))
  (let ((result (cl-rassoc-if #'plusp
                              '(("first" . 1) ("second" . 2) ("third" . 3)))))
    (should (equal result '("first" . 1))))
  (let ((result (cl-rassoc-if (lambda (x) (string= (number-to-string x) "two"))
                              '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result nil)))
  (let ((result (cl-rassoc-if #'stringp
                              '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result nil))))

(ert-deftest cl-rassoc-if-not-test ()
  (let ((result (cl-rassoc-if-not #'evenp
                                  '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result '("one" . 1))))
  (let ((result (cl-rassoc-if-not #'plusp
                                  '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result nil)))
  (let ((result (cl-rassoc-if-not (lambda (x) (< x 5))
                                  '(("one" . 1) ("two" . 2) ("six" . 6)))))
    (should (equal result '("six" . 6))))
  (let ((result (cl-rassoc-if-not (lambda (x) (= x 1))
                                  '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result '("two" . 2))))
  (let ((result (cl-rassoc-if-not (lambda (x) (> x 2))
                                  '(("one" . 1) ("two" . 1) ("three" . 3)))))
    (should (equal result '("one" . 1))))
  (let ((result (cl-rassoc-if-not (lambda (x) (and (numberp x) (< x 3)))
                                  '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result '("three" . 3))))
  (let ((result (cl-rassoc-if-not (lambda (x) (equal x 2))
                                  '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result '("one" . 1))))
  (let ((result (cl-rassoc-if-not #'evenp '())))
    (should (equal result nil)))
  (let ((result (cl-rassoc-if-not #'numberp
                                  '(("one" . 1) ("two" . 2) ("three" . 3)))))
    (should (equal result nil)))
  (let ((result (cl-rassoc-if-not (lambda (x) (eql (proper-list-p x) 1))
                                  '(((1 2) . 1) ((3 4) . 2) ((5) . 2)))))
    (should (equal result '((1 2) . 1)))))

(ert-deftest cl-lib-test-set-functions ()
  (let ((c1 (cons nil nil))
        (c2 (cons nil nil))
        (sym (make-symbol "a")))
    (let ((e '())
          (a (list 'a 'b sym nil "" "x" c1 c2))
          (b (list c1 'y 'b sym 'x)))
      (should (equal (cl-set-difference e e) e))
      (should (equal (cl-set-difference a e) a))
      (should (equal (cl-set-difference e a) e))
      (should (equal (cl-set-difference a a) e))
      (should (equal (cl-set-difference b e) b))
      (should (equal (cl-set-difference e b) e))
      (should (equal (cl-set-difference b b) e))
      ;; Note: this test (and others) is sensitive to the order of the
      ;; result, which is not documented.
      (should (equal (cl-set-difference a b) (list 'a  nil "" "x" c2)))
      (should (equal (cl-set-difference b a) (list 'y 'x)))

      ;; We aren't testing whether this is really using `eq' rather than `eql'.
      (should (equal (cl-set-difference e e :test 'eq) e))
      (should (equal (cl-set-difference a e :test 'eq) a))
      (should (equal (cl-set-difference e a :test 'eq) e))
      (should (equal (cl-set-difference a a :test 'eq) e))
      (should (equal (cl-set-difference b e :test 'eq) b))
      (should (equal (cl-set-difference e b :test 'eq) e))
      (should (equal (cl-set-difference b b :test 'eq) e))
      (should (equal (cl-set-difference a b :test 'eq) (list 'a  nil "" "x" c2)))
      (should (equal (cl-set-difference b a :test 'eq) (list 'y 'x)))

      (should (equal (cl-union e e) e))
      (should (equal (cl-union a e) a))
      (should (equal (cl-union e a) a))
      (should (equal (cl-union a a) a))
      (should (equal (cl-union b e) b))
      (should (equal (cl-union e b) b))
      (should (equal (cl-union b b) b))
      (should (equal (cl-union a b) (list 'x 'y 'a 'b sym nil "" "x" c1 c2)))

      (should (equal (cl-union b a) (list 'x 'y 'a 'b sym nil "" "x" c1 c2)))

      (should (equal (cl-intersection e e) e))
      (should (equal (cl-intersection a e) e))
      (should (equal (cl-intersection e a) e))
      (should (equal (cl-intersection a a) a))
      (should (equal (cl-intersection b e) e))
      (should (equal (cl-intersection e b) e))
      (should (equal (cl-intersection b b) b))
      (should (equal (cl-intersection a b) (list sym 'b c1)))
      (should (equal (cl-intersection b a) (list sym 'b c1))))))

(ert-deftest cl-intersection-test ()
  (let ((result (cl-intersection '(1 2 3 4) '(3 4 5 6))))
    (should (equal result '(4 3))))
  (let ((result (cl-intersection '(1 2) '(3 4))))
    (should (equal result '())))
  (let ((result (cl-intersection '(1 2 3) '(1 2 3))))
    (should (equal result '(1 2 3))))
  (let ((result (cl-intersection '(1 1 2 3) '(1 2 2 3 4))))
    (should (equal result '(3 2 1 1))))
  (let ((result (cl-intersection `(1 ,(copy-sequence "two") 3) '(3 "two" 4))))
    (should (equal result '(3))))
  (let ((result (cl-intersection '(1 2 3) '(3 2 1) :test #'equal)))
    (should (equal result '(1 2 3))))
  (let ((result (cl-intersection '(1 2 3) '(3 4 5) :key #'identity)))
    (should (equal result '(3))))
  (let ((result (cl-intersection '() '(1 2 3))))
    (should (equal result '())))
  (let ((result (cl-intersection '() '())))
    (should (equal result '())))
  (let ((result (cl-intersection '(1 2 3 4 5) '(3 4 5 6 7 8))))
    (should (equal result '(5 4 3)))))

(ert-deftest cl-nintersection-test ()
  (should-not (cl-nintersection () ()))
  (should-not (cl-nintersection () '(1 2 3)))
  (should-not (cl-nintersection (list 1 2) '(3 4)))
  (should (equal (cl-nintersection (list 1 2 3 4) '(3 4 5 6))
                 '(4 3)))
  (should (equal (cl-nintersection (list 1 2 3) '(1 2 3))
                 '(1 2 3)))
  (should (equal (cl-nintersection (list 1 1 2 2 3) '(2 2 3 4))
                 '(3 2 2)))
  (should (equal (cl-nintersection (list 1 (copy-sequence "two") 3)
                                   '(3 "two" 4))
                 '(3)))
  (should (equal (cl-nintersection (list 1 2 3) '(3 2 1) :test #'equal)
                 '(1 2 3))))

(ert-deftest cl-set-difference-test ()
  ;; Our set-difference preserves order, though it is not required to
  ;; by CL standards.  Nevertheless better keep that invariant.
  (should (equal (cl-set-difference '(1 2 3 4) '(3 4 5 6))
                 '(1 2)))
  (let ((result (cl-set-difference '(1 2 3) '())))
    (should (equal result '(1 2 3))))
  (let ((result (cl-set-difference '(1 2 3) '(1 2 3))))
    (should (equal result '())))
  (let ((result (cl-set-difference '(1 1 2 3 4) '(3 4 5))))
    (should (equal result '(1 1 2))))
  (let ((result (cl-set-difference '(1 2 3) '(3 2 4))))
    (should (equal result '(1))))
  (let ((result (cl-set-difference '(1 2 3) '(3 2 1) :test #'equal)))
    (should (equal result '())))
  (let ((result (cl-set-difference '((1 . "one") (2 . "two") (3 . "three"))
                                   '((1 . "uno") (2 . "dos"))
                                   :key #'car)))
    (should (equal result '((3 . "three")))))
  (let ((result (cl-set-difference '() '(1 2 3))))
    (should (equal result '())))
  (let ((result (cl-set-difference '(1 2 3) '())))
    (should (equal result '(1 2 3))))
  (let ((result (cl-set-difference '(1 2 3 4 5) '(3 4 5 6 7))))
    (should (equal result '(1 2))))
  (let ((list1 (list 1 2 3))
        (list2 (list 2 3 4)))
    (should (equal (cl-set-difference list1 list2) '(1)))
    (should (equal list1 '(1 2 3)))
    (should (equal list2 '(2 3 4)))))

(ert-deftest cl-nset-difference ()
  ;; Our nset-difference doesn't preserve order.
  (let* ((l1 (list 1 2 3 4)) (l2 (list 3 4 5 6))
         (diff (cl-nset-difference l1 l2)))
    (should (memq 1 diff))
    (should (memq 2 diff))
    (should (length= diff 2))
    (should (equal l2 '(3 4 5 6))))
  (let* ((l1 (list "1" "2" "3" "4")) (l2 (list "3" "4" "5" "6"))
         (diff (cl-nset-difference l1 l2 :test #'equal)))
    (should (member "1" diff))
    (should (member "2" diff))
    (should (length= diff 2))
    (should (equal l2 '("3" "4" "5" "6"))))
  (let* ((l1 (list '(a . 1) '(b . 2) '(c . 3) '(d . 4)))
         (l2 (list '(c . 3) '(d . 4) '(e . 5) '(f . 6)))
         (diff (cl-nset-difference l1 l2 :key #'car)))
    (should (member '(a . 1) diff))
    (should (member '(b . 2) diff))
    (should (length= diff 2))
    (should (equal l2 '((c . 3) (d . 4) (e . 5) (f . 6)))))
  (let* ((l1 (list '("a" . 1) '("b" . 2) '("c" . 3) '("d" . 4)))
         (l2 (list '("c" . 3) '("d" . 4) '("e" . 5) '("f" . 6)))
         (diff (cl-nset-difference l1 l2 :key #'car :test #'string=)))
    (should (member '("a" . 1) diff))
    (should (member '("b" . 2) diff))
    (should (length= diff 2))
    (should (equal l2 '(("c" . 3) ("d" . 4) ("e" . 5) ("f" . 6))))))

(ert-deftest cl-nset-difference-test ()
  (should-not (cl-nset-difference () ()))
  (should-not (cl-nset-difference () (list 1 2 3)))
  (should-not (cl-nset-difference (list 1 2 3) '(1 2 3)))
  (should-not (cl-nset-difference (list 1 2 3) '(3 2 1) :test #'equal))
  (should (equal (cl-nset-difference (list 1 2 3) ())
                 '(1 2 3)))
  (should (equal (cl-nset-difference (list 1 2 3 4) '(3 4 5 6))
                 '(1 2)))
  (should (equal (cl-nset-difference (list 1 1 2 2 3) '(3 4 5))
                 '(1 1 2 2)))
  (should (equal (cl-nset-difference (list 1 2 3) '(3 2 4))
                 '(1)))
  (should (equal (cl-nset-difference (list 1 2 3 4 5) '(3 4 5 6 7))
                 '(1 2)))
  (should (equal (cl-nset-difference (list 1 (copy-sequence "a")) '(1 "a"))
                 '("a"))))

(ert-deftest cl-set-exclusive-or-test ()
  (let ((result (cl-set-exclusive-or '(1 2 3) '(3 4 5))))
    (should (equal result '(1 2 4 5))))
  (let ((result (cl-set-exclusive-or '(1 2 3) '())))
    (should (equal result '(1 2 3))))
  (let ((result (cl-set-exclusive-or '() '(3 4 5))))
    (should (equal result '(3 4 5))))
  (let ((result (cl-set-exclusive-or '(1 2 3) '(1 2 3))))
    (should (equal result nil)))
  (let ((result (cl-set-exclusive-or '(1 1 2 3) '(3 4 5))))
    (should (equal result '(1 1 2 4 5))))
  (let ((result (cl-set-exclusive-or '(1 2 3) '(3 3 4 5))))
    (should (equal result '(1 2 4 5))))
  (let ((result (cl-set-exclusive-or '(1 2 3) '(3 2 4))))
    (should (equal result '(1 4))))
  (let ((result (cl-set-exclusive-or '(1 2 3) '(3 2 1) :test #'equal)))
    (should (equal result '())))
  (let ((result (cl-set-exclusive-or '() '())))
    (should (equal result '())))
  (let ((list1 (list 1 2 3 4 5))
        (list2 (list 3 4 5 6 7)))
    (should (equal (cl-set-exclusive-or list1 list2) '(1 2 6 7)))
    (should (equal list1 '(1 2 3 4 5)))
    (should (equal list2 '(3 4 5 6 7)))))

(ert-deftest cl-nset-exclusive-or-test ()
  (should-not (cl-nset-exclusive-or () ()))
  (should-not (cl-nset-exclusive-or (list 1 2 3) (list 1 2 3)))
  (should-not (cl-nset-exclusive-or (list 1 2 3) (list 3 2 1) :test #'equal))
  (should (equal (cl-nset-exclusive-or (list 1 2 3) (list 3 4 5))
                 '(1 2 4 5)))
  (should (equal (cl-nset-exclusive-or (list 1 2 3) ())
                 '(1 2 3)))
  (should (equal (cl-nset-exclusive-or (list 1 1 2 2 3) (list 3 4 5))
                 '(1 1 2 2 4 5)))
  (should (equal (cl-nset-exclusive-or (list 1 2 3) (list 3 3 4 5))
                 '(1 2 4 5)))
  (should (equal (cl-nset-exclusive-or (list 1 2 3) (list 3 2 4))
                 '(1 4)))
  (should (equal (cl-nset-exclusive-or () (list 1 2 3))
                 '(1 2 3)))
  (should (equal (cl-nset-exclusive-or (list 1 2 3 4 5) (list 3 4 5 6 7))
                 '(1 2 6 7))))

(ert-deftest cl-subsetp-test ()
  (should (cl-subsetp '(1 2) '(1 2 3 4)))
  (should (cl-subsetp () '(1 2 3 4)))
  (should-not (cl-subsetp '(1 2) ()))
  (should (cl-subsetp '(1 2 3) '(1 2 3)))
  (should (cl-subsetp '(1 1 2) '(1 2 3)))
  (should (cl-subsetp '(1 2) '(1 1 2 3 4)))
  (should-not (cl-subsetp '(1 "two" 3) '(3 "two" 1)))
  (should (cl-subsetp '(1 2) '(2 1) :test #'equal))
  (should (cl-subsetp '((1 . "one") (2 . "two"))
                      '((1 . "uno") (2 . "dos"))
                      :key #'car))
  (should (cl-subsetp '(1 2) '(3 4 2 1) :test #'eq))
  (should (cl-subsetp '((1 2) (3)) '((1 2 . "found") (3 . "found")) :key #'car))
  (should (cl-subsetp '(1 2) '(1 2 3 2)))
  (should (cl-subsetp () ())))

(defun cl--oddp-safe (x)
  (and (numberp x) (oddp x)))

(ert-deftest cl-subst-if-test ()
  (should (equal (cl-subst-if 'X #'cl--oddp-safe '(1 2 (3 4 5) 6))
                 '(X 2 (X 4 X) 6)))
  (should (equal (cl-subst-if 'X #'cl--oddp-safe '(1 2 (3 4 5) 6)
                              :key (lambda (x) (and (numberp x) (1+ x))))
                 '(1 X (3 X 5) X))))

(ert-deftest cl-subst-if-not-test ()
  (should (equal (cl-subst-if-not 'X (lambda (x) (or (not (numberp x)) (oddp x)))
                                  '(1 2 (3 4 5) 6))
                 '(1 X (3 X 5) X)))
  (should (equal (cl-subst-if-not 'X (lambda (x) (or (not (numberp x)) (oddp x)))
                                  '(1 2 (3 4 5) 6)
                                  :key (lambda (x) (and (numberp x) (1+ x))))
                 '(X 2 (X 4 X) 6))))

(ert-deftest cl-nsubst-test ()
  (should (equal (let ((tree (list 'a 'b (list 'c 'd 'a) 'e)))
                   (cl-nsubst 'X 'a tree))
                 '(X b (c d X) e)))
  (should (equal (let ((tree (list 'a 'b (list 'c 'd 'a) 'e)))
                   (cl-nsubst 'X 'a tree
                              :test #'eq))
                 '(X b (c d X) e)))
  (should (equal (let ((tree (list 'a 'b (list 'c 'd 'a) 'e)))
                   (cl-nsubst 'X 'a tree
                              :test-not (lambda (a b) (or (consp b) (eq a b)))))
                 '(a X (X X a . X) X . X)))
  (should (equal (let ((tree (list (cons 1 'a) (cons 2 'b) (cons 3 'a))))
                   (cl-nsubst 'X 'a tree
                              :key #'cdr-safe))
                 '(X (2 . b) X))))

(ert-deftest cl-nsubst-if-test ()
  (should (equal (let ((tree (list 1 2 (list 3 4 5) 6)))
                   (cl-nsubst-if 'X #'cl--oddp-safe tree))
                 '(X 2 (X 4 X) 6)))
  (should (equal (let ((tree (list 1 2 (list 3 4 5) 6)))
                   (cl-nsubst-if 'X #'cl--oddp-safe tree
                                 :key (lambda (x) (and (numberp x) (1+ x)))))
                 '(1 X (3 X 5) X))))

(ert-deftest cl-nsubst-if-not-test ()
  (should (equal (let ((tree (list 1 2 (list 3 4 5) 6)))
                   (cl-nsubst-if-not 'X
                                     (lambda (x) (or (not (numberp x)) (oddp x)))
                                     tree))
                 '(1 X (3 X 5) X)))
  (should (equal (let ((tree (list 1 2 (list 3 4 5) 6)))
                   (cl-nsubst-if-not 'X
                                     (lambda (x) (or (not (numberp x)) (oddp x)))
                                     tree
                                     :key (lambda (x) (and (numberp x) (1+ x)))))
                 '(X 2 (X 4 X) 6))))

(ert-deftest cl-sublis-test ()
  (should (equal (cl-sublis '((a . x) (b . y)) '(a b (a c)))
                 '(x y (x c))))
  (should (equal (cl-sublis '((1 . x) (2 . y)) '(1 2 (3 4))
                            :key (lambda (x) (and (numberp x) (1- x))))
                 '(1 x (y 4))))
  (should (equal (cl-sublis '(("a" . x) ("b" . y)) '("a" "b" ("a" "c"))
                            :test #'equal)
                 '(x y (x "c"))))
  (should (equal (cl-sublis '(("a" . x) ("b" . y)) '("a" "b" ("a" "c"))
                            :test-not #'equal)
                 'x)))

(ert-deftest cl-nsublis-test ()
  (should (equal (let ((tree (list 'a 'b '(a c))))
                   (cl-nsublis '((a . x) (b . y)) tree))
                 '(x y (x c))))
  (should (equal (let ((tree (list '(1 . a) '(2 . b) '(3 . c))))
                   (cl-nsublis '((a . x) (b . y)) tree))
                 '((1 . x) (2 . y) (3 . c)))))

(ert-deftest cl-tree-equal-test ()
  (should (cl-tree-equal '(1 (2 3) 4) '(1 (2 3) 4)))
  (should-not (cl-tree-equal '(1 (2 3) 4) '(1 (2 3) 5)))
  (should (cl-tree-equal '(("a" . 1) ("b" . 2)) '(("a" . 1) ("b" . 2)) :test #'equal))
  (should-not (cl-tree-equal '(("a" . 1) ("b" . 2)) '(("a" . 1) ("b" . 3)) :test #'equal))
  (should (cl-tree-equal '(1 2 3) '(1 2 3) :key (lambda (x) (and x (1+ x)))))
  (should (cl-tree-equal '(a b c) '(a b c) :key #'symbol-name :test #'equal))
  (should-not (cl-tree-equal '(1 2 3) '(1 2 3) :test-not #'eq))
  (should (cl-tree-equal '(1 2 3) '(1 2 3) :key #'identity :test #'eq)))

(provide 'cl-seq-tests)
;;; cl-seq-tests.el ends here