move codemirror extensions into their own folder

client/components/codeEditor/extensions/customFolding.js

@@ -0,0 +1,46 @@
+import { foldService, codeFolding } from '@codemirror/language';
+
+const foldOnPages = [
+	foldService.of((state, lineStart)=>{ //tells where to fold
+		const doc = state.doc;
+		const matcher = /^(?=\\page(?:break)?(?: *{[^\n{}]*})?$)/m;
+
+		const startLine = doc.lineAt(lineStart);
+		const prevLineText = startLine.number > 1 ? doc.line(startLine.number - 1).text : '';
+
+		if(!matcher.test(prevLineText)) return null;
+
+		let endLine = startLine.number;
+		while (endLine < doc.lines && !matcher.test(doc.line(endLine + 1).text)) {
+			endLine++;
+		}
+
+		if(endLine === startLine.number) return null;
+
+		return { from: startLine.from, to: doc.line(endLine).to };
+	}),
+	codeFolding({
+		preparePlaceholder : (state, range)=>{
+			const doc = state.doc;
+			const start = doc.lineAt(range.from).number;
+			const end = doc.lineAt(range.to).number;
+
+			if(doc.line(start).text.trim()) return ` ↤ Lines ${start}-${end} ↦`;
+
+			const preview = Array.from({ length: end - start }, (_, i)=>doc.line(start + 1 + i).text.trim()
+			).find(Boolean) || `Lines ${start}-${end}`;
+
+			return ` ↤ ${preview.replace('{', '').slice(0, 50).trim()}${preview.length > 50 ? '...' : ''} ↦`;
+		},
+		placeholderDOM(view, onclick, prepared) {
+			const span = document.createElement('span');
+			span.className = 'cm-fold-placeholder';
+			span.textContent = prepared;
+			span.onclick = onclick;
+			span.style.color = '#989898';
+			return span;
+		},
+	}),
+];
+
+export default foldOnPages;