mirror of
https://github.com/deepseek-ai/deepseek-harness
synced 2026-08-15 21:04:50 +00:00
87 lines
3.3 KiB
TypeScript
87 lines
3.3 KiB
TypeScript
/**
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* Minimal dependency-free HTML-to-readable-text conversion for `web_fetch`, not a full parser. It
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* removes non-content elements and tags, decodes common entities, collapses whitespace, and keeps
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* basic headings, lists, and links. A richer converter can replace it without changing the seam or
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* tool schema.
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* @module @deepseek-ai/dsh-tool-web/html
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*/
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/** Decode the handful of HTML entities common in textual content. */
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function decodeEntities(text: string): string {
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return text
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.replace(/&(#[xX][0-9a-fA-F]+|#[0-9]+|[a-zA-Z]+);/g, (match, entity: string) => {
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if (entity.startsWith('#x') || entity.startsWith('#X')) {
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const code = Number.parseInt(entity.slice(2), 16)
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return safeFromCodePoint(code, match)
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}
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if (entity.startsWith('#')) {
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const code = Number.parseInt(entity.slice(1), 10)
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return safeFromCodePoint(code, match)
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}
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return NAMED_ENTITIES[entity] ?? match
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})
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}
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const NAMED_ENTITIES: Record<string, string> = {
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amp: '&', lt: '<', gt: '>', quot: '"', apos: "'", nbsp: ' ',
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copy: '©', reg: '®', trade: '™', hellip: '…', mdash: '—', ndash: '–',
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}
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function safeFromCodePoint(code: number, fallback: string): string {
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try {
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return String.fromCodePoint(code)
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} catch {
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// An out-of-range code point (RangeError) is the only failure here; keep the
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// original entity text rather than throwing out of pure presentation.
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return fallback
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}
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}
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/**
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* Convert an HTML document to a readable markdown-ish text approximation.
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* Best-effort and lossy by design — fidelity is the job of a future heavier
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* converter, not this fallback.
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*
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* @param html - the raw HTML source.
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* @returns plain text with markdown headings, list bullets, and links;
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* whitespace collapsed to at most one blank line and trimmed.
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*/
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export function htmlToMarkdown(html: string): string {
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let text = html
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// Drop non-content elements entirely (including their contents).
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.replace(/<script\b[^>]*>[\s\S]*?<\/script>/gi, '')
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.replace(/<style\b[^>]*>[\s\S]*?<\/style>/gi, '')
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.replace(/<noscript\b[^>]*>[\s\S]*?<\/noscript>/gi, '')
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.replace(/<!--[\s\S]*?-->/g, '')
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// Convert links to markdown before stripping tags.
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text = text.replace(/<a\b[^>]*\bhref\s*=\s*["']([^"']*)["'][^>]*>([\s\S]*?)<\/a>/gi, (_match, href: string, label: string) => {
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const cleanLabel = label.replace(/<[^>]+>/g, '').trim()
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return cleanLabel.length > 0 ? `[${cleanLabel}](${href})` : href
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})
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// Headings → markdown hashes.
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text = text.replace(/<h([1-6])\b[^>]*>([\s\S]*?)<\/h\1>/gi, (_match, level: string, body: string) => {
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const hashes = '#'.repeat(Number(level))
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return `\n\n${hashes} ${body.replace(/<[^>]+>/g, '').trim()}\n\n`
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})
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// List items → bullets.
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text = text.replace(/<li\b[^>]*>([\s\S]*?)<\/li>/gi, (_match, body: string) => `\n- ${body.replace(/<[^>]+>/g, '').trim()}`)
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// Block-level breaks become paragraph breaks.
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text = text
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.replace(/<\/(p|div|section|article|header|footer|tr|table|ul|ol|blockquote)>/gi, '\n\n')
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.replace(/<br\s*\/?>/gi, '\n')
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// Drop all remaining tags, decode entities, collapse whitespace.
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text = text.replace(/<[^>]+>/g, '')
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text = decodeEntities(text)
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text = text
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.replace(/[ \t\f\v]+/g, ' ')
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.replace(/ *\n */g, '\n')
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.replace(/\n{3,}/g, '\n\n')
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.trim()
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return text
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}
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