[ADD] Test for normal behavior

KeyWeeUsr · Aug 17, 2024 · 8ec016b · 8ec016b
1 parent 6425778
commit 8ec016b
Showing 1 changed file with 48 additions and 0 deletions.
diff --git a/typewriter-roll-mode-tests.el b/typewriter-roll-mode-tests.el
@@ -5,13 +5,61 @@
 (require 'ert)
 (require 'typewriter-roll-mode)
 
+(defun typewriter-roll--cursor-line ()
+  (line-number-at-pos))
+(defun typewriter-roll--top-line ()
+  (line-number-at-pos (window-start)))
+
 (ert-deftest trm-backspace ()
   (should (not
            (let ((this-command "hello"))
              (typewriter-roll--is-backspace))))
   (should (let ((this-command 'delete-backward-char))
             (typewriter-roll--is-backspace))))
 
+(ert-deftest normal-behavior ()
+  "Write something until it overflows `fill-column', then scroll it away."
+  (let ((scroll-margin 0)
+        (typewriter-roll-keep-in-focus 0))
+    (with-temp-buffer
+      (switch-to-buffer (current-buffer))
+      (let* ((old-win-start (window-start))
+             (old-win-end (window-end))
+             (old-text "text text")
+             (expected-text (format "%s\ntext" old-text)))
+        ;; initial text
+        (insert old-text)
+        ;; default state
+        (should (string= (buffer-string) old-text))
+        (should (eq (typewriter-roll--cursor-line) 1))
+        (should (eq (typewriter-roll--top-line) 1))
+
+        (let ((fill-column 10))
+          (typewriter-roll-mode)
+
+          (typewriter-roll--scroll-main (current-column))
+          ;; default state, not enough chars to fill `fill-column'
+          (should (string= (buffer-string) old-text))
+          (should (eq (typewriter-roll--cursor-line) 1))
+          (should (eq (typewriter-roll--top-line) 1))
+
+          (insert " text")
+          (should (string= (buffer-string) (format "%s text" old-text)))
+          (should (eq (typewriter-roll--cursor-line) 1))
+          (should (eq (typewriter-roll--top-line) 1))
+
+          ;; only after
+          (typewriter-roll--scroll-main (current-column))
+          (should (string= (buffer-string) expected-text))
+          (should (eq (typewriter-roll--cursor-line) 2))
+          (should (eq (typewriter-roll--top-line) 2))
+
+          (insert " ")  ; will be removed by filling
+          (typewriter-roll--scroll-main (current-column))
+          (should (string= (buffer-string) expected-text))
+          (should (eq (typewriter-roll--cursor-line) 2))
+          (should (eq (typewriter-roll--top-line) 2)))))))
+
 (provide 'typewriter-roll-mode-tests)
 
 ;;; typewriter-roll-mode-tests.el ends here