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Unicode text input is broken with CodeMirror 4.8 (needs upgrade) #223
Description
Hi, While working on an Arabic-script translation for TryRuby (PR #222 – Persian),
I noticed that text input in the editor is unreliable for Unicode content.
TryRuby currently uses CodeMirror 4.8, which has known issues with Unicode/BiDi text handling. This can result in incorrect character order and cursor behavior (e.g. Persian text rendering in reverse).
This is not a CSS or direction issue, but a limitation of the old CodeMirror 4.x text insertion logic. This directly affects the usability of Arabic-script languages.
Suggestion: upgrade CodeMirror to a newer version (5.x or later).
Even a minor upgrade should significantly improve Unicode input handling.
Activity
Goudarz commentedon Jan 6, 2026
CC @hsbt 🙏🏻
Goudarz commentedon Oct 5, 2026
CC @hsbt 🙏🏻
hsbt commentedon Oct 6, 2026
Fixed in #254, which is now live on https://try.ruby-lang.org/. The cause was a Bootstrap style rule rather than CodeMirror 4.8, so the editor did not need an upgrade. If Persian text still looks wrong in your browser, please let me know.