| 1 | // A highlight.js span can cross newlines. Balance it at each line boundary so |
| 2 | // React can retain unchanged line hosts without losing multiline token styles. |
| 3 | export function splitHighlightedCodeLines(html: string): string[] { |
| 4 | const lines: string[] = []; |
| 5 | const openTags: string[] = []; |
| 6 | let current = ""; |
| 7 | let offset = 0; |
| 8 | const closeTags = () => [...openTags].reverse() |
| 9 | .map(tag => tag.startsWith("<mark") ? "</mark>" : "</span>").join(""); |
| 10 | while (offset < html.length) { |
| 11 | if (html[offset] === "\n") { |
| 12 | lines.push(current + closeTags()); |
| 13 | current = openTags.join(""); |
| 14 | offset += 1; |
| 15 | continue; |
| 16 | } |
| 17 | if (html[offset] === "<") { |
| 18 | const end = html.indexOf(">", offset); |
| 19 | if (end !== -1) { |
| 20 | const tag = html.slice(offset, end + 1); |
| 21 | current += tag; |
| 22 | if (/^<(span|mark)\b/.test(tag)) openTags.push(tag); |
| 23 | else if (/^<\/(span|mark)>$/.test(tag)) openTags.pop(); |
| 24 | offset = end + 1; |
| 25 | continue; |
| 26 | } |
| 27 | } |
| 28 | const length = (html.codePointAt(offset) ?? 0) > 0xffff ? 2 : 1; |
| 29 | current += html.slice(offset, offset + length); |
| 30 | offset += length; |
| 31 | } |
| 32 | lines.push(current + closeTags()); |
| 33 | return lines; |
| 34 | } |
| 35 |