trilium/packages/codemirror/src/index.ts

import { defaultKeymap } from "@codemirror/commands";
import { EditorView, keymap, lineNumbers, type EditorViewConfig } from "@codemirror/view";

export default class CodeMirror extends EditorView {
    constructor(config: EditorViewConfig) {
        super({
            ...config,
            extensions: [
                keymap.of(defaultKeymap),
                lineNumbers()
            ]
        });
    }
}