@tanstack/markdown/dist/extensions/callouts.js

A tiny, fast, deterministic Markdown renderer for blogs and documentation.

export function calloutsExtension() {
    return {
        name: 'callouts',
        parseBlock: parseCalloutBlock,
    };
}
export function parseCalloutBlock(context) {
    const first = context.lines[context.index] ?? '';
    const match = first.match(/^ {0,3}>\s*\[!([A-Za-z]+)\](?:\s+(.*))?$/);
    if (!match)
        return undefined;
    const kind = match[1].toLowerCase();
    const title = match[2]?.trim() || titleCase(kind);
    const body = [];
    let cursor = context.index + 1;
    while (cursor < context.lines.length) {
        const line = context.lines[cursor] ?? '';
        if (/^\s*$/.test(line)) {
            body.push('');
            cursor++;
            continue;
        }
        const quoted = line.match(/^ {0,3}>\s?(.*)$/);
        if (!quoted)
            break;
        body.push(quoted[1]);
        cursor++;
    }
    context.consume(cursor - context.index);
    return {
        type: 'callout',
        kind,
        title,
        children: context.parseBlocks(body.join('\n')),
    };
}
function titleCase(value) {
    return value.slice(0, 1).toUpperCase() + value.slice(1).toLowerCase();
}