Use lexical-binding in tempo.el and add tests

For discussion, see the following thread:
https://lists.gnu.org/archive/html/emacs-devel/2019-05/msg00395.html
* lisp/tempo.el: Use lexical-binding.
(tempo-define-template): Expand documentation to mention
`tempo-user-elements'.
(tempo-local-tags, tempo-collection, tempo-dirty-collection)
(tempo-marks, tempo-match-finder): Define with defvar-local.
(tempo-named-insertions, tempo-region-start, tempo-region-stop): Make
them automatically buffer-local.
* test/lisp/tempo-tests.el: Add tests for tempo.el.

2 files changed, 246 insertions, 23 deletions

diff --git a/lisp/tempo.el b/lisp/tempo.el
index 28afbec0f49..e3b9c76a5b8 100644
--- a/lisp/tempo.el
+++ b/lisp/tempo.el
@@ -1,11 +1,11 @@
-;;; tempo.el --- Flexible template insertion
+;;; tempo.el --- Flexible template insertion -*- lexical-binding: t; -*-
 
 ;; Copyright (C) 1994-1995, 2001-2019 Free Software Foundation, Inc.
 
 ;; Author: David Kågedal <davidk@lysator.liu.se>
 ;; Created: 16 Feb 1994
 ;; Kågedal's last version number: 1.2.4
-;; Keywords: extensions, languages, tools
+;; Keywords: abbrev, extensions, languages, tools
 
 ;; This file is part of GNU Emacs.
 
@@ -152,7 +152,7 @@ setting it to (upcase), for example.")
 (defvar tempo-tags nil
   "An association list with tags and corresponding templates.")
 
-(defvar tempo-local-tags '((tempo-tags . nil))
+(defvar-local tempo-local-tags '((tempo-tags . nil))
   "A list of locally installed tag completion lists.
 It is an association list where the car of every element is a symbol
 whose variable value is a template list.  The cdr part, if non-nil,
@@ -161,16 +161,16 @@ documentation for the function `tempo-complete-tag' for more info.
 
 `tempo-tags' is always in the last position in this list.")
 
-(defvar tempo-collection nil
+(defvar-local tempo-collection nil
   "A collection of all the tags defined for the current buffer.")
 
-(defvar tempo-dirty-collection t
+(defvar-local tempo-dirty-collection t
   "Indicates if the tag collection needs to be rebuilt.")
 
-(defvar tempo-marks nil
+(defvar-local tempo-marks nil
   "A list of marks to jump to with `\\[tempo-forward-mark]' and `\\[tempo-backward-mark]'.")
 
-(defvar tempo-match-finder "\\b\\([[:word:]]+\\)\\="
+(defvar-local tempo-match-finder "\\b\\([[:word:]]+\\)\\="
   "The regexp or function used to find the string to match against tags.
 
 If `tempo-match-finder' is a string, it should contain a regular
@@ -195,23 +195,15 @@ A list of symbols which are bound to functions that take one argument.
 This function should return something to be sent to `tempo-insert' if
 it recognizes the argument, and nil otherwise.")
 
-(defvar tempo-named-insertions nil
+(defvar-local tempo-named-insertions nil
   "Temporary storage for named insertions.")
 
-(defvar tempo-region-start (make-marker)
+(defvar-local tempo-region-start (make-marker)
   "Region start when inserting around the region.")
 
-(defvar tempo-region-stop (make-marker)
+(defvar-local tempo-region-stop (make-marker)
   "Region stop when inserting around the region.")
 
-;; Make some variables local to every buffer
-
-(make-variable-buffer-local 'tempo-marks)
-(make-variable-buffer-local 'tempo-local-tags)
-(make-variable-buffer-local 'tempo-match-finder)
-(make-variable-buffer-local 'tempo-collection)
-(make-variable-buffer-local 'tempo-dirty-collection)
-
 ;;; Functions
 
 ;;
@@ -268,11 +260,14 @@ The elements in ELEMENTS can be of several types:
  - `n>': Inserts a newline and indents line.
  - `o': Like `%' but leaves the point before the newline.
  - nil: It is ignored.
- - Anything else: It is evaluated and the result is treated as an
-   element to be inserted.  One additional tag is useful for these
-   cases.  If an expression returns a list (l foo bar), the elements
-   after `l' will be inserted according to the usual rules.  This makes
-   it possible to return several elements from one expression."
+ - Anything else: Each function in `tempo-user-elements' is called
+   with it as argument until one of them returns non-nil, and the
+   result is inserted.  If all of them return nil, it is evaluated and
+   the result is treated as an element to be inserted.  One additional
+   tag is useful for these cases.  If an expression returns a list (l
+   foo bar), the elements after `l' will be inserted according to the
+   usual rules.  This makes it possible to return several elements
+   from one expression."
   (let* ((template-name (intern (concat "tempo-template-"
                                        name)))
          (command-name template-name))
diff --git a/test/lisp/tempo-tests.el b/test/lisp/tempo-tests.el
new file mode 100644
index 00000000000..6e610ffa6ea
--- /dev/null
+++ b/test/lisp/tempo-tests.el
@@ -0,0 +1,228 @@
+;;; tempo-tests.el --- Test suite for tempo.el  -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2019 Free Software Foundation, Inc.
+
+;; Author: Federico Tedin <federicotedin@gmail.com>
+;; Keywords: abbrev
+
+;; 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 'tempo)
+(eval-when-compile (require 'cl-lib))
+
+(ert-deftest tempo-string-element-test ()
+  "Test a template containing a string element."
+  (with-temp-buffer
+    (tempo-define-template "test" '("GNU Emacs Tempo test"))
+    (tempo-insert-template 'tempo-template-test nil)
+    (should (equal (buffer-string) "GNU Emacs Tempo test"))))
+
+(ert-deftest tempo-p-bare-element-test ()
+  "Test a template containing a bare `p' element."
+  (with-temp-buffer
+    (tempo-define-template "test" '("abcde" p))
+    (tempo-insert-template 'tempo-template-test nil)
+    (tempo-forward-mark)
+    (should (equal (point) 6))))
+
+(ert-deftest tempo-r-bare-element-test ()
+  "Test a template containing a bare `r' element."
+  (with-temp-buffer
+    (tempo-define-template "test" '("abcde" r "ghijk"))
+    (insert "F")
+    (set-mark (point))
+    (goto-char (point-min))
+    (tempo-insert-template 'tempo-template-test t)
+    (should (equal (buffer-string) "abcdeFghijk"))))
+
+(ert-deftest tempo-p-element-test ()
+  "Testing template containing a `p' (prompt) element."
+  (with-temp-buffer
+    (tempo-define-template "test" '("hello " (p ">")))
+    (let ((tempo-interactive t))
+      (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "world")))
+        (tempo-insert-template 'tempo-template-test nil))
+      (should (equal (buffer-string) "hello world")))))
+
+(ert-deftest tempo-P-element-test ()
+  "Testing template containing a `P' (prompt) element."
+  (with-temp-buffer
+    (tempo-define-template "test" '("hello " (P ">")))
+    ;; By default, `tempo-interactive' is nil, `P' should ignore this.
+    (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "world")))
+      (tempo-insert-template 'tempo-template-test nil))
+    (should (equal (buffer-string) "hello world"))))
+
+(ert-deftest tempo-r-element-test ()
+  "Testing template containing an `r' (with prompt) element."
+  (with-temp-buffer
+    (tempo-define-template "test" '("abcde" (r ">") "ghijk"))
+    (let ((tempo-interactive t))
+      (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "F")))
+        (tempo-insert-template 'tempo-template-test nil))
+      (should (equal (buffer-string) "abcdeFghijk")))))
+
+(ert-deftest tempo-s-element-test ()
+  "Testing template containing an `s' element."
+  (with-temp-buffer
+    (tempo-define-template "test" '("hello " (p ">" P1) " " (s P1)))
+    (let ((tempo-interactive t))
+      (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "world!")))
+        (tempo-insert-template 'tempo-template-test nil))
+      (should (equal (buffer-string) "hello world! world!")))))
+
+(ert-deftest tempo-&-element-test ()
+  "Testing template containing an `&' element."
+  (tempo-define-template "test" '(& "test"))
+  (with-temp-buffer
+    (insert "  ")
+    (tempo-insert-template 'tempo-template-test nil)
+    (should (equal (buffer-string) "  test")))
+  (with-temp-buffer
+    (insert "hello")
+    (tempo-insert-template 'tempo-template-test nil)
+    (should (equal (buffer-string) "hello\ntest"))))
+
+(ert-deftest tempo-%-element-test ()
+  "Testing template containing an `%' element."
+  (tempo-define-template "test" '("test" %))
+  (with-temp-buffer
+    (tempo-insert-template 'tempo-template-test nil)
+    (should (equal (buffer-string) "test")))
+  (with-temp-buffer
+    (insert "hello")
+    (goto-char (point-min))
+    (tempo-insert-template 'tempo-template-test nil)
+    (should (equal (buffer-string) "test\nhello"))))
+
+(ert-deftest tempo-n-element-test ()
+  "Testing template containing an `n' element."
+  (tempo-define-template "test" '("test" n "test"))
+  (with-temp-buffer
+    (tempo-insert-template 'tempo-template-test nil)
+    (should (equal (buffer-string) "test\ntest"))))
+
+(ert-deftest tempo-n>-element-test ()
+  "Testing template containing an `n>' element."
+  (tempo-define-template "test" '("(progn" n> "(list 1 2 3))"))
+  (with-temp-buffer
+    (emacs-lisp-mode)
+    (tempo-insert-template 'tempo-template-test nil)
+    ;; Tempo should have inserted two spaces before (list 1 2 3)
+    (should (equal (buffer-string) "(progn\n  (list 1 2 3))"))))
+
+(ert-deftest tempo->-element-test ()
+  "Testing template containing a `>' element."
+  (with-temp-buffer
+    (emacs-lisp-mode)
+    (insert "(progn\n)")
+    (backward-char)
+    (tempo-define-template "test" '("(list 1 2 3)" >))
+    (tempo-insert-template 'tempo-template-test nil)
+    ;; Tempo should have inserted two spaces before (list 1 2 3)
+    (should (equal (buffer-string) "(progn\n  (list 1 2 3))"))))
+
+(ert-deftest tempo-r>-bare-element-test ()
+  "Testing template containing a bare `r>' element."
+  (with-temp-buffer
+    (tempo-define-template "test" '("(progn" n r> ")"))
+    (emacs-lisp-mode)
+    (insert "(list 1 2 3)")
+    (set-mark (point))
+    (goto-char (point-min))
+    (tempo-insert-template 'tempo-template-test t)
+    ;; Tempo should have inserted two spaces before (list 1 2 3)
+    (should (equal (buffer-string) "(progn\n  (list 1 2 3))"))))
+
+(ert-deftest tempo-r>-element-test ()
+  "Testing template containing an `r>' (with prompt) element."
+  (tempo-define-template "test" '("(progn" n (r> ":") ")"))
+  (with-temp-buffer
+    ;; Test on-region use
+    (emacs-lisp-mode)
+    (insert "(list 1 2 3)")
+    (set-mark (point))
+    (goto-char (point-min))
+    (tempo-insert-template 'tempo-template-test t)
+    (should (equal (buffer-string) "(progn\n  (list 1 2 3))")))
+  (with-temp-buffer
+    ;; Test interactive use
+    (emacs-lisp-mode)
+    (let ((tempo-interactive t))
+      (cl-letf (((symbol-function 'read-string) (lambda (&rest _) "  (list 1 2 3)")))
+        (tempo-insert-template 'tempo-template-test nil))
+      (should (equal (buffer-string) "(progn\n  (list 1 2 3))")))))
+
+(ert-deftest tempo-o-element-test ()
+  "Testing template containing an `o' element."
+  (with-temp-buffer
+    (tempo-define-template "test" '("test" o))
+    (insert "hello")
+    (goto-char (point-min))
+    (tempo-insert-template 'tempo-template-test nil)
+    (should (equal (buffer-string) "test\nhello"))
+    (should (equal (point) 5))))
+
+(ert-deftest tempo-nil-element-test ()
+  "Testing template with nil elements."
+  (with-temp-buffer
+    (tempo-define-template "test" '("Hello," nil " World!"))
+    (tempo-insert-template 'tempo-template-test nil)
+    (should (equal (buffer-string) "Hello, World!"))))
+
+(ert-deftest tempo-eval-element-test ()
+  "Testing template with Emacs Lisp expressions."
+  (with-temp-buffer
+    (tempo-define-template "test" '((int-to-string (+ 1 1)) "=" (concat "1" "+1")))
+    (tempo-insert-template 'tempo-template-test nil)
+    (should (equal (buffer-string) "2=1+1"))))
+
+(ert-deftest tempo-l-element-test ()
+  "Testing template containing an `l' element."
+  (with-temp-buffer
+    (tempo-define-template "test" '("list: " (l "1, " "2, " (int-to-string (+ 1 2)))))
+    (tempo-insert-template 'tempo-template-test nil)
+    (should (equal (buffer-string) "list: 1, 2, 3"))))
+
+(ert-deftest tempo-tempo-user-elements-test ()
+  "Testing a template with elements for `tempo-user-elements'."
+  (with-temp-buffer
+    (make-local-variable 'tempo-user-elements)
+    (add-to-list 'tempo-user-elements (lambda (x) (int-to-string (* x x))))
+    (tempo-define-template "test" '(1 " " 2 " " 3 " " 4))
+    (tempo-insert-template 'tempo-template-test nil)
+    (should (equal (buffer-string) "1 4 9 16"))))
+
+(ert-deftest tempo-expand-tag-test ()
+  "Testing expansion of a template with a tag."
+  (with-temp-buffer
+    (tempo-define-template "test" '("Hello, World!") "hello")
+    (insert "hello")
+    (tempo-complete-tag)
+    (should (equal (buffer-string) "Hello, World!"))))
+
+(ert-deftest tempo-expand-partial-tag-test ()
+  "Testing expansion of a template with a tag, with a partial match."
+  (with-temp-buffer
+    (tempo-define-template "test" '("Hello, World!") "hello")
+    (insert "hel")
+    (tempo-complete-tag)
+    (should (equal (buffer-string) "Hello, World!"))))
+
+(provide 'tempo-tests)
+;;; tempo-tests.el ends here