J.H Editor turns into Excel search tool, not just Markdown

The project started as a way to learn AI while building something concrete. The first version was written entirely by hand, but basic editor behavior — cursor movement, PageUp/PageDown scrolling, and keeping typed characters in sync with the cursor — proved surprisingly hard to get right. After the developer consulted AI, CodeMirror 6 was recommended; adopting it removed the need to manage those fundamentals and freed attention for features. The AI used was Gemini at first, then Claude, and development reportedly sped up after the switch.

From there the editor's character shifted. Markdown editing and viewing were fully separated, with block-level editing in a modal that shows source and live preview side by side. But the feature that became most used was Excel search and preview: pressing Ctrl+Shift+R opens a file search, typing part of a name narrows thousands of files in milliseconds, and Enter shows a read-only preview that preserves column widths, merged cells and borders. CSV files open as tables without automatic formatting that can corrupt values, and XML/JSON get a tree view alongside source. These were added after the foundation was in place, not planned from the start.

The result is cluttered: beyond the four highlighted features, it also includes diff and merge, a Git panel, large log viewing, Mermaid diagrams, slide view and 14 themes. The developer admits that even he only realized Excel search was the most convenient part after using it for a while, and that a first-time user told "this is a Markdown editor" would rarely find it. Other stated issues are the lack of code signing, which triggers a Windows warning during install, and that only a Windows version exists.