when typing markdown and the windows has to scroll and "scroll-on" an error occur

[marcnicole]

Describe the bug

the bug is located in getCmRangeHeight(mdNode, cm) which calls getNextEmptyLineHeight with only 2 parameters instead of 3 and cause getNextEmptyLineHeight to crash

(screen shot are on toastui-editor 2.0.1, just modified to debug)

To Reproduce

simply type a lot of new line in the markdown, when it has to scroll it will soon cause the error

Expected behavior

simply correct the return statement as shown above

Screenshots

we see here the root cause of the problem: one parameter is invalid

Desktop (please complete the following information):

• OS: Windows (but OS independent)
• Browser chrome
• Version 81.0.4044.122

[seonim-ryu]

@marcnicole
Thank you for explaining in detail! 👍 But I can't reproduce, can you show me what the situation is with an image like a gif? And can you check if it happens in the example page below?

https://nhn.github.io/tui.editor/latest/tutorial-example01-editor-basic

[marcnicole]

@seonim-ryu
I can't reproduce the problem on https://nhn.github.io/tui.editor/latest/tutorial-example01-editor-basic, but I can't check the source code neither because it is webpacked / minimized .

I used the npm deployement...so I have a single large file. I will look if I can find the difference in the source. maybe an issue with the npm package... I will look , but I need some time

[seonim-ryu]

@marcnicole Looking at the screenshot you gave me again, I think the location of the offending code is here.

tui.editor/apps/editor/src/js/scroll/helper.js

Line 67 in a2dc672

let detailLineInfo = lineInfo.handle;

But to debug, I have to reproduce the current situation, but I can't reproduce it, so it's difficult to solve this problem..

[HiroyukiNIshimura]

When I handle Null, it’s cured.

before

while (start <= end && !detailLineInfo.text.trim()) {
  height += detailLineInfo.height;
  start += 1;
  detailLineInfo = cm.lineInfo(start).handle;
}

after

while (start <= end && !detailLineInfo.text.trim()) {
  height += detailLineInfo.height;
  start += 1;
  if (!cm.lineInfo(start)) {
    break;
  }
  detailLineInfo = cm.lineInfo(start).handle;
}

[ndhhien27]

This bug still occurs in React. Does someone have a solution to fix it?

[ndhhien27]

The error occurs when we scroll in the write tab with a empty line at the end of editor