very-small-parser/lib/markdown/is.js

A very small Markdown, HTML, and CSS parser.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.is = void 0;
// Headings H1-H6.
const h1 = /(^|\n) {0,3}#{1,6} {1,8}[^\n]{1,64}\r?\n\r?\n\s{0,32}\S/;
// Bold, italic, underline, strikethrough, highlight.
const bold = /(?:\s|^)(_|__|\*|\*\*|~~|==|\+\+)(?!\s).{1,64}(?<!\s)(?=\1)/;
// Basic inline link (also captures images).
const link = /\[[^\]]{1,128}\]\(https?:\/\/\S{1,999}\)/;
// Inline code.
const code = /(?:\s|^)`(?!\s)[^`]{1,48}(?<!\s)`([^\w]|$)/;
// Unordered list.
const ul = /(?:^|\n)\s{0,5}\-\s{1}[^\n]+\n\s{0,15}\-\s/;
// Ordered list.
const ol = /(?:^|\n)\s{0,5}\d+\.\s{1}[^\n]+\n\s{0,15}\d+\.\s/;
// Horizontal rule.
const hr = /\n{2} {0,3}\-{2,48}\n{2}/;
// Fenced code block.
const fences = /(?:\n|^)(```|~~~|\$\$)(?!`|~)[^\s]{0,64} {0,64}[^\n]{0,64}\n[\s\S]{0,9999}?\s*\1 {0,64}(?:\n+|$)/;
// Classical underlined H1 and H2 headings.
const title = /(?:\n|^)(?!\s)\w[^\n]{0,64}\r?\n(\-|=)\1{0,64}\n\n\s{0,64}(\w|$)/;
// Blockquote.
const blockquote = /(?:^|(\r?\n\r?\n))( {0,3}>[^\n]{1,333}\n){1,999}($|(\r?\n))/;
/**
 * Returns `true` if the source text might be a markdown document.
 *
 * @param src Source text to analyze.
 */
const is = (src) => h1.test(src) ||
    bold.test(src) ||
    link.test(src) ||
    code.test(src) ||
    ul.test(src) ||
    ol.test(src) ||
    hr.test(src) ||
    fences.test(src) ||
    title.test(src) ||
    blockquote.test(src);
exports.is = is;