Problem with emojis/unicode (assumed double-width?)

[mofux]

In current v3, Emojis seem to take up two cells. Using the arrow keys, two cells are jumped instead of one. Deleting also clears two cells.

[Tyriar]

I can't reproduce this on macOS/bash. I wouldn't expect it to happen unless we tried to tweak with the emoji width (make it non-1). Any more details on repro steps would be useful.

[mofux]

Reproduce (OSX, MacOS High Sierra)

• start v3 demo
• paste 😀 multiple times
• hit left arrow key multiple times, see how it jumps two cells each time and runs into the cell boundaries.

Are you already on MacOS High Sierra, because I am? Maybe it is also related to node-pty - I can see that when inserting an emoji in Terminal.app it automatically adds a space after the emoji, and even more, I cannot select that space, it's like High Sierra would threat it as a double-width character...

Terminal.app on MacOS High Sierra

[Tyriar]

This might be a high sierra thing where they tried to make Emojis better in the terminal? I can't update currently as it messes up rendering in Electron apps.

[mofux]

I hate to say that I've upgraded and now I'm stuck with tons of rendering glitches in all those chromium based apps 😤

[Tyriar]

Yeah I was careful to track feedback before updating as similar things happened with Sierra I think.

[Tyriar]

I notice that Terminal.app has a nice emoji experience where they're treated as proper wide characters, we can probably do it if they can 😄

[mandel59]

UAX #11 East Asian Width, Revision 31 changed emoji East Asian Wide (double-width), and wcswidth in wchar.h returns the width of strings. I guess macOS High Sierra would have supported the update.
xterm.js's wcwidth in src/CharWidth.ts doesn't have supported it yet.

[Tyriar]

@mandel59 thanks for the info!

[Tyriar]

@mandel59 I think this issue is specific to emoji, I think CJK chars should be correctly categorized as double width chars (some components may be broken though like #1387)