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143 | import { esc } from "./html";
/**
* Compact markdown renderer for README/about pages. Supported: headings,
* fenced code, lists, blockquotes, hr, links, images, emphasis, inline
* code, autolinks. Not supported: tables, footnotes, raw HTML (everything
* is escaped first; only http(s)/relative/# link targets are allowed).
*/
function safeUrl(url: string): string | null {
const u = url.trim();
if (/^(https?:)?\/\//i.test(u) || u.startsWith("#") || /^[\w./-]/.test(u)) {
if (/^javascript:/i.test(u) || /^data:/i.test(u) || /^vbscript:/i.test(u)) return null;
return u;
}
return null;
}
function inline(text: string): string {
let s = esc(text);
// inline code first (protects its content from other rules)
s = s.replace(/`([^`]+)`/g, (_m, code) => `<code>${code}</code>`);
// images
s = s.replace(/!\[([^\]]*)\]\(([^)\s]+)(?:\s+"[^&]*")?\)/g, (_m, alt, url) => {
const u = safeUrl(url);
return u ? `<img src='${u}' alt='${alt}' style='max-width:100%'/>` : alt;
});
// links
s = s.replace(/\[([^\]]+)\]\(([^)\s]+)(?:\s+"[^&]*")?\)/g, (_m, txt, url) => {
const u = safeUrl(url);
return u ? `<a href='${u}'>${txt}</a>` : txt;
});
// bold, italics
s = s.replace(/\*\*([^*]+)\*\*/g, "<strong>$1</strong>");
s = s.replace(/(^|[\s(])\*([^*\s][^*]*)\*/g, "$1<em>$2</em>");
s = s.replace(/(^|[\s(])_([^_\s][^_]*)_/g, "$1<em>$2</em>");
// autolink bare urls (not already inside an attribute)
s = s.replace(/(^|[\s(])(https?:\/\/[^\s<)]+)/g, "$1<a href='$2'>$2</a>");
return s;
}
export function renderMarkdown(src: string): string {
const lines = src.replaceAll("\r\n", "\n").split("\n");
const out: string[] = [];
let para: string[] = [];
let inCode = false;
let codeLines: string[] = [];
let listStack: ("ul" | "ol")[] = [];
let quote = false;
const flushPara = () => {
if (para.length) {
out.push(`<p>${inline(para.join("\n"))}</p>`);
para = [];
}
};
const closeLists = (depth: number) => {
while (listStack.length > depth) out.push(`</${listStack.pop()}>`);
};
const closeQuote = () => {
if (quote) {
out.push("</blockquote>");
quote = false;
}
};
for (const raw of lines) {
if (inCode) {
if (/^\s*(```|~~~)\s*$/.test(raw)) {
out.push(`<pre class='md-code'><code>${esc(codeLines.join("\n"))}</code></pre>`);
codeLines = [];
inCode = false;
} else {
codeLines.push(raw);
}
continue;
}
const fence = raw.match(/^\s*(```|~~~)\s*(\S*)\s*$/);
if (fence) {
flushPara();
closeLists(0);
closeQuote();
inCode = true;
continue;
}
const heading = raw.match(/^(#{1,6})\s+(.*)$/);
if (heading) {
flushPara();
closeLists(0);
closeQuote();
const level = heading[1].length;
out.push(`<h${level}>${inline(heading[2].replace(/\s+#+\s*$/, ""))}</h${level}>`);
continue;
}
if (/^\s*([-*_])\s*\1\s*\1[\s\-*_]*$/.test(raw)) {
flushPara();
closeLists(0);
closeQuote();
out.push("<hr/>");
continue;
}
const bq = raw.match(/^\s*>\s?(.*)$/);
if (bq) {
flushPara();
closeLists(0);
if (!quote) {
out.push("<blockquote>");
quote = true;
}
out.push(inline(bq[1]) + "<br/>");
continue;
}
const li = raw.match(/^(\s*)([-*+]|\d+[.)])\s+(.*)$/);
if (li) {
flushPara();
closeQuote();
const depth = Math.min(Math.floor(li[1].length / 2), 3) + 1;
const kind: "ul" | "ol" = /^[-*+]$/.test(li[2]) ? "ul" : "ol";
while (listStack.length < depth) {
out.push(`<${kind}>`);
listStack.push(kind);
}
closeLists(depth);
out.push(`<li>${inline(li[3])}</li>`);
continue;
}
if (/^\s*$/.test(raw)) {
flushPara();
closeLists(0);
closeQuote();
continue;
}
// setext-ish: plain text joins the current paragraph
closeLists(0);
closeQuote();
para.push(raw);
}
if (inCode) out.push(`<pre class='md-code'><code>${esc(codeLines.join("\n"))}</code></pre>`);
flushPara();
closeLists(0);
closeQuote();
return out.join("\n");
}
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