DRY up highlighting code

webview-ui/src/utils/highlight.ts

@@ -0,0 +1,44 @@
+export function highlightFzfMatch(text: string, positions: number[], highlightClassName: string = "history-item-highlight") {
+	if (!positions.length) return text
+
+	const parts: { text: string; highlight: boolean }[] = []
+	let lastIndex = 0
+
+	// Sort positions to ensure we process them in order
+	positions.sort((a, b) => a - b)
+
+	positions.forEach((pos) => {
+		// Add non-highlighted text before this position
+		if (pos > lastIndex) {
+			parts.push({
+				text: text.substring(lastIndex, pos),
+				highlight: false
+			})
+		}
+
+		// Add highlighted character
+		parts.push({
+			text: text[pos],
+			highlight: true
+		})
+
+		lastIndex = pos + 1
+	})
+
+	// Add any remaining text
+	if (lastIndex < text.length) {
+		parts.push({
+			text: text.substring(lastIndex),
+			highlight: false
+		})
+	}
+
+	// Build final string
+	return parts
+		.map(part =>
+			part.highlight
+				? `<span class="${highlightClassName}">${part.text}</span>`
+				: part.text
+		)
+		.join('')
+}